Investigation of the performance of electronic equalization applied to receiver in the optical communication systems is introduced. Compared with other digital equalizers, maximum likelihood sequence estimator (MLSE) equalizer seems to be the most promising candidate solution to mitigate impairments caused by chromatic dispersion (CD), polarization mode dispersion (PMD) and fiber’s nonlinearity. The performance of a novel MLSE digital equalizer technology is analyzed and it is combined with feed-forward equalizer (FFE) receivers in optical 40 Gb/s polarization-maltiplexed (Pol-Mux) RZ-DQPSK systems. The MLSE receiver combined with FFE technique can achieve a higher CD tolerance and a long haul transmission with 280 km without any optical dispersion compensation and meanwhile the bit error ratio (BER) of the receiver is less than 10-3.

The frequency-locked multi-carrier source is a key element for achieving Tb/s data rate transmission. It has high frequency efficiency and its implement is simple. Therefore, it has become the topic in high-speed mass optical fiber communication system. The structure of the I/Q modulator and the operation principle for generating multi-carrier are analyzed in theory, the experimental system of frequency-locked multi-carrier source based on I/Q modulator is set up. The 15-carrier space at 12.5 GHz generation is successfully conducted. Simultaneously, the parameters affecting the performance of the muti-carrier source is analyzed by simulation. The results show that the radio frequency drive voltage, the variation of states of polarization are main factors to affect the generation of the frequency-locked multi-carrier source.

A novel type of photonic crystal fiber (PCF) with low dispersion and high nonlinearity for four-wave mixing is proposed. This kind of fiber is composed of a solid silica core and a cladding with squeezed-hexagonal-lattice elliptical air-hole along the fiber length. Its dispersion and nonlinearity coefficient are investigated simultaneously by using full vectorial finite element method. Numerical results show that proposed highly-nonlinear low-dispersion fiber has the total dispersion as low as ±2.5 ps/(nm·km) over ultra-broad wavelength range from 1.43 μm to 1.8 μm by adjusting the structure parameters of photonic crystal fiber, such as the hexagonal squeezing ratio, the relative air hole size and the air hole ellipticity, and the corresponding nonlinearity coefficient is about 150 (W·km)-1 at 1.55 μm. The proposed PCF with low ultra-flattened dispersion, high nonlinearity and high birefringence can have important applications on the four-wave mixing.

Based on defect mode theory and slow light effects, a new scheme of encoder/decoder in 2D-opticalcode division multiple acess (2D-OCDMA) which uses multi-channel photonic crystal (PC) filter is proposed. According to couple-mode theory, user signals were cut into several pulses in accordance with the address code sequence due to the defect resonator. Then, the frequency encoded of user signal in 2D-OCDMA can be performed. Because of the slow light effects of PC waveguide，the time delay of the structure in micron magnitude is up to nanometer magnitude, which comes up to the standard of correct encoding and decoding. The centre wavelength of the three-channel encoder of 2D-OCDMA are 1545.00, 1555.30 and 1570.60 nm respectively, and the time delay between dot defects is 0.4 ns. Without sidelobe in the transmission spectrum, there is no interference in decoding, which ensures the accuracy in the process of encoding and decoding.

To make the optical systems simply controlled and easily realized in wireless optical communications, the design scheme of an automatic control device is put forward based on the optical closed－loop mode in which the volume and the inertia of the optical systems of collimating and beam expanding are small. Using the feedback control technology for reference, a light path of close－loop feedback is done with the pulse laser as control signal. The system is achieved by the micro controller unit (MCU) and the photoelectric detectors. Meanwhile, the hardware configuration and the software design scheme of the autocontrol device are presented, the former includes the MCU control system, stepping motor set, photoelectric detection system and feedback system, and the latter contains the control protocol and programmed function modules. Furthermore, the experimental results show that the automatic control device has the advantages of smooth operation and reliable automatic control. Thus, this study has practical value on the research of the light path collimating in wireless optical communications.

The degradation of the performance in wireless non-line-of-sight ultraviolet (UV) communication is due to the presence of the intersymbol interference. Lenst mean square (LMS) class and constant modulus algorithm (CMA) equalizer are studied based on on-off key (OOK) modulation. The results indicate that the bit error rate (BER) is so high that only low bit rate communication can be used. The convergence rate is very slow for LMS equalizer on UV channel, BER is nearly not affected by equalizer tap numbers and step size has an optimal value. The relations between parameters of two variable step size LMS algorithms and BER are obtained. It is proved that UV channel is a minimum phase system and can use blind equalizer. BER is not sensitive to the step size and tap number for CMA blind equalizer.

A stimulated Raman scattering (SRS)-based multiwavelength fiber laser comprising of broadband chirped fiber Bragg grating and Sagnac interleaver is investigated experimentally. Four-wave mixing processes among channels are introduced into the cavity through a length of dispersion-shifted fiber (DSF) with small integrating Raman gain. Results show that four-wave mixing plays a role of transferring energy from higher power channels to lower ones, and the quantity of output wavelength increases from three without DSF to six at the same pump level.

Supercontinuum generation is one of the most important applications of photonic crystal fibers. An optical pulsed laser, of pulse width smaller than 1 ns, repetition rate about 6.85 kHz, average output optical power lower than 100 mW, and central wavelength near 1064.5 nm, is used to pump a segment of highly nonlinear photonic crystal fibers with length about 15 m, air hole diameter 2.205 μm, hole-hole space 3.359 μm, average core diameter 4.5 μm, zero dispersion wavelength 1016 nm. Then a flat supercontinuum of spectrum span over 1100 nm is obtained. The supercontinuum is also a series of optical pulses, whose repetition rate is the same as the pumping pulse, and each single pulse is broaden due to the dispersive effect. Except the peak at 1064.5 nm, which is generated by the residual pumping optical power, the power fluctuation is within 10 dB over the whole measuring range of 600~1700 nm. Therefore, an excellent supercontinuum, of low optical power and flat spectrum response, is obtained. It is very useful in various optical measurements, such as ultra-broadband super-width dispersion measurement of fibers.

A sample of multi-cladding high concentration silica host erbium doped fiber with bismuth-gallium-aluminum co-doped is fabricated by MCVD process with a type of annular graphite heater furnace. Its geometric parameters and absorption spectrum are measured and analyzed. It is presented that the mode field diameter and absorption coefficient of the erbium-doped fiber are both increased efficiently by using multi-cladding structure. The absorption reaches to 84 dB/m at 1530 nm and the mode field diameter is 11.6 μm at 1550 nm, but the background loss is 1.5 dB/m. An erbium-doped fiber amplifier is established and the best length of fiber is experimentally found. As a result, a 1.95 m C-band erbium-doped fiber amplifier is presented with small signal gain of 23 dB.

A two-dimensional code/encode based on chirped fiber Bragg grating (CFBG) and fiber Bragg grating (FBG) is proposed. The degradation of autocorrelation peak with wavelength mismatch of the FBG, and the deterioration of bit error rate consequentially, are investigated. The experimental result of output power versus different mismatch wavelengths and hops is given. The results indicate that the decoder based on CFBG can improve output power a little, which also decrease wavelength matching accuracy and provide dispersion compensation.

To solve the problem of calibrating the polarimeter module, a new approach based on vector projection algorithm was proposed, and the principle of calibration was analyzed. The continuous-wave (CW) light passed through the tunable optical attenuator, polarization analyzer, photon detectors of polarimeter module, then the photocurrent was fed into the preamplifier circuit and high-speed analog to digital converter (ADC) in turn. Finally, the digital voltage signals were acquired by the digital signal processor (DSP) and sent to the computer. At the same time, the polarization analyzer exported corresponding Stokes parameters. The calibration matrix could be calculated by the vector projection algorithm based on the given data. The experimental result shows that, in comparison with the common iterative algorithm, the vector projection algorithm has even higher computational efficiency and accuracy. The measured error of the degree of polarization (DOP) is less than 3 percent.

A fiber Bragg grating (FBG) sensing network using code division multiplexing (CDM) and time division multiplexing (TDM) increases the multiplying density, but decreases the network′s dynamic performance and is difficult to be implemented in engineering for its complex structure. A new kind of FBG sensing network using CDM and wavelength division multiplexing (WDM) by coding measuring points directly with 2D-CDMA codes is proposed, which increases the multiplying density while does not influence its dynamic performance and is easy to be implemented in engineering for its simple structure. Simulation experiment indicates that in a spectral range of 10 nm, 49 FBG sensors can be arranged in this type of sensing network, and the measuring range of every sensor reaches 10 nm.

A novel method for active fiber refractive index measurement based on beat frequency interrogation of the multi-longitudinal-mode distributed Bragg reflector (DBR) fiber laser was presented. Based on beat frequency interrogation, the measurement of erbium-doped fiber refractive index had been taken by monitoring the beat note between adjacent longitudinal modes. This method was simple of structure, and low cost compared with the conventional wavelength interrogation approach, etc. The measurement method had been analyzed theoretically and tested experimentally. By utilizing a uniform cantilever beam (UCB) for axial strain on the oscillation cavity, strain dependence of fiber refractive index had been measured. Experimental results indicated that erbium-doped fiber refractive index linearly decreased with strain increased, and its coefficient of determination reached to 0.9971. The strain coefficient of fiber refractive index was about -6.3086×10-7 (με)-1, basically in agreement with earlier related studies.

A novel slit with angular transmittance is proposed and the interference patterns of a vortex beam transformed through the angular slit are investigated theoretically and experimentally with the angular slit by CCD. The method is the observation of the interference pattern. The theoretical results are simulated based on the intensity expression in the far field, which are in consistent with the experimental results .The influence of the slit number and topological charge on the interference pattern are investigated. It is shown that, the interference pattern depends on the number of the angular slits and the topological charge of the vortex beam. It results from the change of the vortex beam phase. The result may have potential application in measuring the topological charge of a vortex beam.

Based on coupled-mode theory and mechanics of materials, the four-core fiber Bragg gratings (F-CFBG) transverse force sensing rules according to transverse load, direction and fiber outer diameter were studied. The F-CFBG reflection spectrum split into two main peaks under transverse load. The resonant wavelength changes and the space between those two peaks are proportional with the applied transverse force magnitude, but decrease as the transverse orientation increases. The ratio of the peak splitting between two cores at 90° separation only lie on the orientation of transverse. The numerical analysis of F-CFBG wavelength shift with different outer diameters was also presented respectively. On condition that normalized frequency keeps constant, the wavelength change and the space between those two peaks increase as the fiber outer diameter decreases, but the increase degree lie on the transverse orientation.

Dispersion is one of the most significant parameters of photonic crystal fibers. The dispersion properties of total internal reflection photonic crystal fibers are numerically studied using the simple empirical relation method and CUDOS simulation software, which is based on the multipole method, by analyzing various numerical methods available currently. And the effects of air hole diameter d, hole pitch Λ, and d/Λ on the dispersion properties are numerically investigated in details, and some results, which are useful for design of photonic crystal fibers, are given. A photonic crystal fiber, whose length is 328 mm, hole diameter is 2.17 μm, and hole pitch is 3.47 μm, is tested using the ultro-broadband and high precision dispersion measurement system constructed previously, which is based on white light interferometer using supercontinuum as the light source. The experimental dispersion curve is well in agreement with the numerical results, and the tested zero-dispersion wavelength and the numerical value are 0.973 μm and 1.018 μm respectively, which well verify the validities of the numerical method and the measurming system.

With the development of photonic integrated circuits and all-optical networks, semiconductor ring lasers (SRL) based on the structure of ring resonator have received increasing attention and have been one of the focuses in the field of integrated optics in recent years. The design, fabrication and test of a semiconductor ring laser with two coupling bus waveguide are reported in this paper. The width of the ring resonator is 3.4 μm, the ring radius is 349 μm, the gap between the ring resonator and the bus waveguides is 1.0 μm, the threshold current of the (SRL) is 36 mA, the free spectral range FSR is 0.33 nm, and the center lasing wavelength is 1566.66 nm when injected current is 61 mA. Coupling an optical fiber to an end of the bus waveguide, the output optical power reaches to 40 μW. Semiconductor ring laser’s bidirectional operation state, unidirectional bistability operation and unstable alternating oscillation operation state are observed through the P-I characteristic plot. At last, the spectral characteristics of lasing and non-lasing are analyzed when the ring laser operates in unidirectional bistable region.

A 1550 nm monolithically integrated resonant cavity-enhanced (RCE) semiconductor photodetector with four-mirror and three-cavity (M4C3) is reported. The contradiction among high quantum efficiency, high response speed and narrow spectral response linewidth is overcome by multi-cavities structure. High-quality GaAs/InP heteroepitaxy is realized by employing a low-temperature buffer layer. By adopting M4C3 structure, high quantum efficiency, high response speed, and narrow spectral response linewidth can be obtained simultaneously. Peak quantum efficiency of about 70%, spectral linewidth of 0.5 nm and 3 dB bandwidth of 8.0 GHz have been obtained in this device.

Automatic segmentation is a core technology for dendritic spines detection, identification and reconstruction. A novel level set segmentation method is proposed for neuron object in 3D fluorescence confocal images. In the fist step, 3D image are smoothed and enhanced by curvature anisotropic diffusion filter, and then the level set speed images are computed. In the second step, the seed points of neuron object are computed automatically located at the extreme local iso-surface curvature, which correspond to the local ridge or valley points on neuron object. Then in the third step, the fast marching method is used to produce the initial level set shape images. In the last step, the initial level set shape images are passed as input to the shape detection based level set algorithm to compute the final 3D neuron object. This method reduces the computation time by minimizing level set propagation, which converges at the optimal object within a fixed iteration number. Experiments on 2-photon lasers or 3D fluorescence confocal images demonstrate that this method is effective and efficient.

The principle of confocal scanning microscope is introduced. A THz confocal imaging system is presented based on a CO2 pumped continuous-wave THz laser SIFIR-50, and preliminary study on THz confocal imaging is carried out. The experimental result shows that the combination of confocal microscope and THz imaging can improve the lateral resolution of THz imaging system effectively, which illustrates the exciting potential applications for this emerging technique.

When biological cells or tissue thick specimens are imaged by bio-optical microscopy, image resolution decreased significantly due to the impact of diffraction and defocus. Digital confocal microscopy can improve the image resolution through a three-dimensional image restoration method. The criterions of resolution degradation ratio and resolution improvement ratio are proposed, and a simulation-thick specimen is designed with different lateral and axial spacing of optical points and lines. The full width at half-maximam is used for measurement, evaluation and analysis in the image resolution of thin specimen diffraction imaging, thick specimen imaging containing out-of-focus ingredients, and image by restored digital confocal microscopy. The results show that the digital confocal microscopy has high resolution improve ratio, and can restore lateral and axial resolution of thick specimen effectively.

The three-dimensional (3D) dark with high uniform light wall is very useful for many applications such as 3D dark spot microscopy and 3D dark spot trap. A new method is proposed to generate a 3D dark spot surrounded by uniform light at all directions. In this method, a double-ring-shaped radially polarized beam and a single-ring-shaped azimuthally polarized beam are incoherently superimposed. When two component beams of the composite beam have a proper intensity ratio, a 3D dark spot with high uniform light wall can be generated by focusing the composite beam. Compared with the result obtained from a single double-ring-shaped radially polarized beam focusing, the uniformity of the light wall surrounding the 3D dark spot obtained from the superimposed beam focusing can be increased twice or more.

The rate equations of fluorophore are solved with Runge-Kutta algorithm, and the process of the excitation and the depletion in stimulated emission depletion (STED) microscope is analyzed in detail. Gaussian shaped pulse is used to simulate ther excitation and the depletion process. The pump time versus the exciting time and intensity, the depletion time versus the intensity of depletion beam are calculated. With the simulation in an exciting and depletion period, the best synchronization delay time between the excited beam and the STED beam in STED microscope is achieved. These results will play an important role in the microscope setup.

As the electromagnetic environment becomes increasingly complex, the problems of traditional carrier frequency measuring are gradually protruded. So the acousto-optic frequency measurement system is designed. Here the optical signal processing is mainly studied. On the basis of acousto-optic diffraction theory, the mechanisms of acousto-optic deflector dealing with frequency signal are described, and spatial filtering of acousto-optic deflector is analyzed. It is obtained that to some degree the system can reduce the effect of noise, because when different frequency signals are input to the piezoelectric transducer, the volume gratings of different grating constants which will have different influence will be established in the acousto-optic media. By experiment, data is tested in the areas of improving signal to noise ratio, ameliorating signal resolution, and enhancing the processing capacity of the transient signal. It is demonstrated that the system has the features of good real-time performance, high interception rate, wide bandwidth, high precision, handling multi-signal simultaneously etc. And it can realize instantaneous frequency measurement of the multiple signals simultaneously arriving at transducer and fully embody the advantages of acousto-optic deflection system.

Multi-sensor images matching is one of the key steps in vision navigation and multi-sensor images fusion. A common image matching method is to match the features detected in both images separately. However, for the images with great difference in imaging apparatuses, for example, synthetic aperture radar(SAR) image and optical image, it is hard to obtain corresponding features. A edge support (ES) algorithm is proposed to matching multi-sensor images. ES algorithm only needs to detect edge feature in one image and find the maximal support in the transform space of the other image. The ES is calculated by normalizing the summation of orientation gradient. The matching result can be obtained by optimizing the support function through genetic algorithm′s global optimum solution. Experimental results show that the ES algorithm can matching SAR image and optical image effectively.

Objective quality assessment of image mosaic is of fundamental necessary in real-time digital image mosaic system. An image mosaicking quality objective assessment method based on visual information fidelity(VIF) is proposed considering that the results using traditional objective assessment methods do not agree with the results of the human subjective assessment methods. Firstly, assuming that the image sources meet Gaussian scale mixture (GSM) model and regarding image mosaic algorithms as image signal distortion channel, and considering human visual noise characteristics within neurons, VIF digital image mosaic objective quality assessment model is established, and a mosaic image quality evaluation index mosaic visual information fidelity (MVIF) is also derived. And then, the method of estimating the parameters in MVIF assessment algorithm is introduced in detail. Finally, the performance of MVIF assessment algorithm has been validated with lots of mosaic images. The experiment indicates that the method can evaluate mosaic image quality correctly and its objective evaluation results are more consistent with subjective evaluation results than those of traditional methods.

A fast de-blurring variational model for optical remote sensing image is proposed. In the proposed model, the de-blurring and de-nosing parts can be divided into two alternating minimizing processes using surrogated functional decoupling approach. Combined Fourier domain linear de-blurring filtering and subspace projection de-nosing method together, a novel alternating iterative numerical algorithm is proposed. Two classical point spread functions such as atmosphere turbulence Gaussian blurring and out-of-focus blurring are designed to demonstrate this algorithm′s performance. Experimental results show that the improved signal to noise ratio in this algorithm is about 2 dB larger than that of the gradient decreasing (GD) algorithm and the iterative convergent rate is improved more than one order of magnitude.

In the image denoising methods based on discrete wavelet transform, the generalized cross validation (GCV) algorithm has been proven to be an effective statistical way for estimating the optimal threshold and used widely to remove the image noise. However, GCV has the higher computational complexity than other denoising threshold estimating method. For the high spatial resolution remote sensing image, the GCV algorithm spends most time for computing the wavelet denoising threshold of every subband. An effective and efficient high spatial resolution remote sensing image denosing algorithm based on region of interest (ROI) and fast GCV is proposed. This new algorithm first obtains these image regions of interest (ROI) using shape adaptive integer wavelet transform (SA-IWT) and then computes the denoising threshold of ROI on the high spatial resolution remote sensing image by fast GCV algorithm. Finally, the new algorithm completes the ROI denoising using the soft-threshold merhod. The experimental results show that the new algorithm can not only first complete ROI denoising of the remote sensing image, but also reduce the computational complexity of GCV effectively. This new method is valuable for future high spatial resolution remote sensing image denoising.

Near infrared spectroscopy (NIRs) technology and Mie theory are utilized for scattering characteristics research on radiofrequency ablation of biological tissue. Firstly, NIRs is utilized to monitor the radiofrequency ablation surgery rats in real-time so as to explore the relationship between reduced scattering coefficient (RSC) μ′s and the degree of thermally induced tissue coagulation. Then, Mie theory is utilized to analyze the morphological changes of biological tissue so as to explore the basic mechanism of the changes of optical parameters caused by thermally induced tissue coagulation. Results show that there is a close relationship between μ′s and the degree of thermally induced tissue coagulation; the degree of thermal coagulation can be obtained by the value of μ′s; when biological tissue thermally coagulates, the average equivalent scattering particle radius decreases, the particle density increases, and the anisotropy factor decreases.

The shear-warp algorithm is used to reconstruct optical coherence tomography images (OCT) of the tooth in vitro. 3D reconstruction image is convenient for doctors to locate lesions and has a great potential for the clinical diagnosis of early dental caries. The basic principle of the shear-warp algorithm is introduced, as well as the all-fiber optical coherence tomography dental diagnosis system and three dimensional reconstruction image of the tooth in vitro based on 97 OCT images.

Recently, reflectometry interference technology has been widely used in detections of biomolecular interaction, food security and drug screening due to its advantages in label-free and dynamic detection. Protein microarray, providing an opportunity to monitor multiple biomolecular interactions simultaneously, has a potential to be used in clinical diagnosis. In this study, we have designed and constructed a label-free, real-time reflectometry interference imaging system that detects interactions of proteins according to optical phase differences from the accumulation of biological material on solid substrates, which can perform the measurement of the change of thickness in nm level. The specific binding between human IgG and anti-human IgG is performed and continuously detected by using this label-free and real-time interference imaging platform. The thickness of SiO2 is optimized so that the interference image with high signal contrast is achieved. In addition, streptavidin coupled microsphere solution is introduced to to enlarge detection signal of the biotin-linked antibody. The experimental results show that the microsphere efficiently increases the intensity of binding sites and improves the sensitivity of detection.

Cavitation effect induced by holmium laser pulses firstly happens when fiber-transmitted holmium laser pulses ablate biological tissues under liquid environment. Then liquid thermodynamics can directly determine the overall mechanisms of laser-tissue interaction. Free-running holmium laser pulses with pulse duration of 300 μs ［full width at half-maximum (FWHM)］ and wavelength of 2.12 μm are used to ablate calculus consisting of calcium oxalate monohydrate (COM) and uric acid (UC) constituents. After irradiation the crater tomographic image is measured by optical coherent microscopy (OCM) technology to quantify width, height, and volume. Experimental results indicate after multi-pulse irradiation with the same energy of a single pulse, the difference of the surface tomography is much more obvious. The ablation efficiency in water is much higher than that in air. This indicates that liquid can contribute to the laser-substance interaction.

In order to improve the accuracy of colorimetric characterization of digital image devices, an adaptively polynomial model based on Gaussian weighted function is proposed. Certain nearest training samples are adaptively selected for each target sample, and a Gaussian function is designed to weight the contribution of each training sample, and then the least-squares method is adopted to get the coefficients of the corresponding polynomial models. An experiment is implemented to colorimetric characterization of digital still cameras with the proposed model, common polynomial model and polynomial model based on inverse distance weighted function. The experimental results indicate that the prediction accuracy of the proposed model is highest in all the training and testing samples combinations.

In order to research the spatial characteristics of human vision system, the luminance and chromatic contrast sensitivity function (CSF) is measured for sinusoid wave patterns on a CRT displayer using the psychophysical method of interleaved staircase. Based on the CIELAB space, the contrast is defined as the ratio between color difference ΔE*ab and the average luminance L*, so that the luminance and chromatic CSF can be compared in the uniform scale. The luminance and chromatic CSF for the sinusoid wave patterns whose average color is neutral gray (L*=76，a*=b*=0) are measured under three field sizes of 10°, 6° and 2.44°, respectively, for spatial frequencies from 0.5 to 23.4 cycle /(°). The test data are fitted using different exponent functions. It is found that the peak luminance CSF values and the cross points of chromatic CSF curves of different color directions change with the field sizes. The ratio curves between the luminance CSF and the chromatic CSF under different fields are also obtained, which reflect the difference of human′s sensitivity to the luminance and chromatic contrast.

A multi-sample parallel estimation method using in the volume-holographic scene matching system is proposed. The method makes good use of the characteristics of stationary random of the remote sensing image and the characteristics of the high speed, multi-channel and high parallelism of the volume holographic correlator, and implements scene matching with high accuracy. Theoretical basement of multi-sample parallel estimation method is analyzed. The essential steps of the method including image preprocessing, template images preparation and estimation equation establishing are discussed in detail and the requirements for these steps are introduced. The experimental results show the validity of the multi-sample parallel estimation method, and the recognition accuracy is improved by increasing the sample numbers.

Limited by diffraction effect, the size of focused IR spot is usually larger than the pixel pitch of FPAs, hence the crosstalk testing is quite difficult. A crosstalk experimental setup of infrared focal plane array (IRFPA) is introduced briefly. Estimating methods of IR spot size are studied. Furthermore a new crosstalk measuring method called “spot shifting method” is presented. Finally, a determining method of spot shifting distance is given. The focused spot is controlled to scan over the center of an interested pixel along the row (or column) of the FPA. At the same time the output signal of the interested pixel and the spot position are recorded. With these, the spot size is estimated. By centering the focused spot on the interested pixel then shifting the spot to left for a proper distance, the crosstalk of the irradiated pixel to right adjacent pixel is measured. After a similar shifting, crosstalk to other adjacent pixel is also measured. It is vital to select a proper shifting distance. With this spot shifting method, crosstalk is measured even when the pixel size of FPA is smaller than the spot size.

Based on the research of the actuality with microelectronic device reliability testing and electronic speckle pattern interferometer (ESPI), a method that predicts the specimen life time according to the change of out-of-plane displacement of packing is presented. In the method, temperature control system is used to provide the condition of accelerated temperature stress, and the working lifetime of specimen at normal temperature is estimated by the activation energy of specimen extracted according to out-of-plane displacement law. When the specimens S8550 are given the temperature range from 100 ℃ to 190 ℃, the speckle interference stripes are collected at every temperature points. Then the activation energy of specimen is extracted rapidly, and the working lifetime of the specimen at temperature of 50 ℃ and100 ℃ is obtained. The experimental results agree with the data in references well, which demonstrates the feasibility of the proposed method.

The research was made in fabrication and application of multimode waveguides using the Ag+-Na+ ion-exchange technique in glass. First, Ag+-Na+ ion exchange was run in nitrate melt . Then a electric field was applied. By using this method it is possible to control independently the width and depth of the waveguide. Three-dimensional beam propagation method (3D-BPM) was utilized to simulate and design power splitters with multimode interference (MMI) structure and Y-junction. The measurement results with 1550 nm light showed that the measured loss of multimode straight waveguide can be lower than 0.28 dB/cm, and the insertion loss was 3.6 dB, and uniformity of the splitters was 0.21 dB. It is proved that the fabrication process was adjustable with parameters and reliable on repeatability, which makes it suitable for optical power splitters with high performance.

Three asymmetric structures are introduced into cross-section of holey fiber by changing the size of diameters of micro holes near the fiber core while maintaining the hexagonal lattice. The linear variation of birefringence over wavelength is controlled and expanded by the compensation between the positive and negative ones. Full-wave beam-propagation-method is used to calculate influence of different structural parameters on the beat-length dispersion, including the material dispersion of fused silica. Considering the permission of fabrication art, flat dispersion curve of beat-length about 9 cm is obtained by parameters′ optimization in super-wide band covering both 1310 nm and 1550 nm wavelength windows commonly used in the optical telecommunications. The relative change of beat-length is less than 0.15% in 1250~1650 nm band, and 0.85% in 1000~1900 nm. This optimal fiber is suitable for making wideband fiber-optic wave-plate used in fiber sensors to promote the systematic stability and liability.

Optical fiber smart metal structures can be formed by embedding fiber Bragg grating (FBG) sensors into the metal matrix can. The stress sensing of the FBG is affected by the embedding method and the characteristics of the interlayer and the matrix. FBG sensors with nickel protective coating are embedded into the metal component using soldering method. The theoretical model for embedded FBG’s wavelength trend with external force is developed. Bending tests are carried out to test the transversal stress sensing of the embedded FBG sensors. The experimental results show, that the model is feasible to forecast the transversal stress sensing of embedded FBG.

A novel surface plasmons (SP) sensor system for gas with high-refractive index resolution is designed. The method of reflective wavelength detection is used in the system of gas sensor that works in wavelength of optical fiber communications. The sensor is based on a metal grating with a spacer between the periodic strips and a metal film (MGS). The SP excited by gratings, is constrainted in the waveguide layer between the metal grating and the metal coatings, which enhances the SP effect, makes the SP resonance peak seasitive to the charge of gas index. This gas sensor has higher sensitivity compared with metal grating sensor. The computation demonstrates that the average wavelength resolution over the range of 1.000~1.001 is approximately 3050 nm/RIU, which is twice more than metal grating-based gas sensors. The minimum resonance peak reflectivity and the full width at half maximum (FWHM) values are only 0.25% and 4.2 nm, respectively. The gas sensor based on MGS has the characteristics of high sensitivity and resolution, safe, ease of integration, enabling real-time detection and remote monitoring. It has very important application value for gas refractive index detection.

A comb-filter based on Mach-Zehnder interferometer (MZI) is experimentally fabricated by splicing a section of single mode twin-core fiber (TCF) between two single mode fibers (SMFs). The wavelength spacing between the adjacent transmission peaks of the transmission spectrum of the device versus wavelength, the length of the TCF and the effective index difference between the two cores are analyzed. When a wavelength is chosen, the wavelength spacing between the adjacent transmission peaks is proportional to the square of the wavelength and inversely proportional to the product of length of the TCF and the effective index difference between the two cores. The insertion loss, the flatness of the transmission spectra and the extinction ratio of the fabricated comb-filters are tested and analyzed. The insertion loss of the device decreases effectively by tapering the splicing regions between the SMFs and TCF. The device with insertion loss about 7 dB is obtained and comb-filter with extinction ratio about 13 dB are obtained. The comb-filter with maximum peak power difference as low as 1.59 dB is also obtained. This device is simple and compatible.

All-optical sampling needs femtosecond fiber laser as sampling pulse source. A passively mode-locked erbium-doped femtosecond fiber laser, pumped by 976 nm laser diode, using nonlinear polarization rotation mode-locking mechanism and inline polarization controllers is reported. At pump power of 176 mW, average output power is about 8.1 mW, with 29.69 MHz repetition rate and 16.8 nm spectrum width. The laser is easily mode-locked and stable. All-fiber ring cavity construction makes it compactable and convenient.

The key factors of nonlinear fiber devices are analyzed from the loss aspect. The dependences of insertion loss, reflection loss and intrinsic loss on the input optical power are studied. In the case of high input optical power, the insertion loss is proportional to the input optical power due to the stimulated Brillouin scattering (SBS), and the slope is related to the SBS efficiency. The changes of loss are measured in fiber spools with different diameters. The SBS threshold and the efficiency of four-wave mixing (FWM) in the fiber spool with small diameter are also investigated experimentally. The results indicate that the nonlinear performance of optical devices with a 7cm-diameter fiber spool is basically the same as that of the fiber spool with the conventional diameter, which helps to design the toroidal coil with the magnetic field along the fibers and analyze the characters of the nonlinear magneto-optic fiber.

A novel multi-parameter sensor based on a cascaded long-period fiber grating with two different periods is proposed and demonstrated. The sensing properties of long-period fiber gratings with different periods are investigated in detail which indicate that the long-period fiber gratings with different periods and the resonant peak positions have obvious sensitivity differences to the same changes of the external parameters. Such properties are useful for the design of multi-parameter sensor. Through the control of the fabrication parameters and the period, the fabrication of the cascaded long-period fiber gratings is achieved with the CO2 laser. The temperature and refractive index sensing properties of the cascaded long-period fiber grating are explored through experiments. Multi-parameter sensing is realized with such cascaded long-period fiber gratings in the experiments.

A self-Q-switched and multi-wavelength mode-locked fiber laser which is based on the figure-of-eight cavity is proposed. Multi-wavelength mode-locked with the shortest pulse width of 1.6 ns and the repetition rate of 1.79 MHz are obtained when the total length of the cavity is 106.5 m. The repetition rate of the Q-switched pulse changes with the input pump power and adjustment of the polarization controllers. As we change the length of the cavity, a multi-wavelength fiber laser oscillation which operates around 1612 nm with the line space of 3.3±0.2 nm is generated. Single line, dual and triple line can be obtained by adjusting the polarization controllers.

A LD-pumped passively Q-switched Nd:YAG ceramic laser with a GaAs saturable absorber is demonstrated. At a pump power of 23.3 W, maximum average output power of 2.06 W is obtained, corresponding to optical conversion efficiency of 8.8% and slope efficiency of 9.9%. The highest repetition rate, largest pulse energy, shortest pulse width and highest peak power are measured to be 49.5 kHz, 41.6 μJ, 17 ns and 2.44 kW, respectively.

The fabrication process of holographic polymer dispersed liquid crystal (H-PDLC) and its characteristics are introduced. Optical chopper based on H-PDLC gratings is put forward and experimentally conducted. The specific electrical driving source and controlling system are specially designed for H-PDLC based chopper. The one-channel and two-channel optical choppers based on H-PDLC gratings have been experimentally researched. According to experimental results, the new device proposed enjoys benefits such as rapid response, being without moving parts, being easy to be operated and integrated etc. The convenience of changing its frequencies and duty ratio is its biggest advantage over mechanical ones, which promises the new device has a good application prospect.

Y2.94Al5-2x(MgSi)xO120.06 Ce yellow-phosphors are synthesized by the high temperature solid-state method. The structure and optical properties of samples are characterized by application of powder X-ray diffraction (XRD) and photoluminescence spectroscopy. Moreover, the variation of photoluminescence (PL) and photoluminescence excitation (PLE) spectra are studied as a function of (Mg-Si) concentration as well as the energy level of outer shell electron of Ce3+. XRD analysis reveals that all of the synthesized phosphors are nearly single-phase garnet and no impurity phases are presented. Phosphors show broad yellow emission band in the range of 500～650 nm and two maximum excitation peaks are located at 340 nm and 460 nm. With the increase of (Mg-Si) concentration, the PL spectra presents distinct red-shift. In the PLE spectra, the near ultraviolet excitation band shows blue-shift and the blue excitation band shows red-shift, respectively. Simultaneously, the crystal field strength around Ce3+ is enhanced and the energy level of outer shell electron (5d1) of Ce3+ is broadened.

Blue-emitting Ba1-xSi2O2N2xEu2+(0.01≤x≤0.08) phosphor has been synthesized via an ultrasonic suspension route. The microstructure and photoluminescence properties of the as-synthesized phosphor are characterized by X-ray diffraction (XRD) and photoluminescence spectroscopy, respectively. Its XRD pattern indicates that the BaSi2O2N2Eu2+is the major crystalline phase for all compositions. It can be efficiently excited over a broad excitation band extending from 287 to 460 nm。The BaSi2O2N2Eu2+phosphor has strong blue emission. The emission spectrum consists of a single-peak broadband with a maximum at 487 nm, which may be ascribed to the 4f65d→4f7transition of Eu2+. A larger Stokes shift of Eu2+luminescence is expected at the excitation wavelength of 303 nm than at 397 nm due to nonradiative relaxation. The luminescence intensity is enhanced and a red shift is observed upon increasing Eu2+concentration. When x exceeds 0.02, the emission intensity tends to monotonically decrease due to the Eu2+concentration quenching. This new phosphor has promising applications in phosphor-converted white LED.

As the photocathode practical application mode, transmission-type structure has important signitication for the research. A MOCVD epitaxial p-type GaN, which has sapphire substrate and AlN buffer layer, was designed as transmission-type material. This material was prepared into GaN photocathode by ultra-high vacuum surface cleaning technique and (Cs,O) activation technique. The UV spectral response of prepared GaN photocathode was measured. The testing results showed that the photocathode had obvious gate-shaped response in the transmission mode, and the maximum quantum efficiency was close to 15%. Comparing to the reflection-mode spectral response curve, the overall responses of transmission-mode were lower and long-wave response threshold moved towards shortwave. The experiment results were analyzed from photocathode material structure, epitaxial level and photocathode preparation techniques.

The experiment developed a novel method of microlens array preparation on polymethyl methacrylate (PMMA), which can fabricate the microlens with smooth surface, and the radius of curvature and size of lens could be controled by changing laser machining parameters. Laser irradiation induced glass evaporation and vaporization, so the liquid glass surface tranformed to sphere shape with the effect of surface tension. A microlens formed after the surrounded liquid glass cooling down. The lens radius of curvature could be minished with the laser output enhanced. But when the PMMA was impure or dirty, the microlens were bad with airballes and failure points.

A novel Ti4+ doped SiO2-Al2O3-ZnO-K2CO3 is synthesized. Its X-ray diffraction (XRD) pattern, excitation spectrum and emission spectrum are measured and recorded at room temperature. The X-ray diffraction diffusion (XRD) data demonstrate that there are β-Zn2SiO4 nanocrystals in the glass substrate. Theory computation shows that the size of β-Zn2SiO4 nanocrystals is about 25 nm. Under 275 nm light excitation, the emission band (350～650 nm) originated from Ti4+ ion can be observed in Ti4+ doped glass ceramics. Compared with the precursor glass, upconversion luminescence enhances significantly in the glass ceramics. The CIE coordinate (x=0.242, x=0.363) of the Ti4+ doped glass ceramics heat-treated at 750 ℃ for two hours is close to the standard white-light illumination (X=0.333,Y=0.333). The results indicate that Ti4+ doped glass ceramics containing β-Zn2SiO4 nanocrystals can act as suitable materials for phosphor.

CaSi2N2O2 codoped with Ce (fixed) and varying Tb concentrations were prepared by solid-state synthesis method. Crystalline phase was investigated by powder X-ray diffraction, the Tb, Ce-codoped CaSi2N2O2 phosphors have the monoclinic structure. Excitation spectra and emission spectra were investigated by spectrometer. The results indicated that there were two emission bands centered at 542 nm and 410 nm when excited by 360 nm, which were ascribed to the characteristic emissions of the Tb3+ and Ce3+. Monitored at 542 and 410 nm, respectively, the overlapped excitation spectra were obtained. Moreover, this excitation spectrum of Ce3+ overlapped perfectly with the excitation spectrum of Tb3+. As a result, the energy transfer from Ce3+ to Tb3+ was observed. The results of sample color coordinate analysis show that the Ca0.995-ySi2O2N2 0.005Ce3+, yTb3+ (y=0.06, 0.08, 0.10) is a single host phosphor with superior properties for white light emitting diodes.

The effect of temperature on GaAs nanowires (NWs) growth is investigated. Three samples are grown on GaAs (111) B substrate by Au-assisted metalorganic chemical vapor deposition (MOCVD) using vapor-liquid-solid (VLS) mechanism at 500 ℃, 530 ℃ and 560 ℃, respectively. It is found that all samples are vertical to the substrate. Their length growth at low temperature are independent with their diameters, and the NWs are straight from base to top. The growth rate of thick NWs increase reversely with growth temperature. That is because the VLS mechanism growth is suppressed at high temperature. For thin NWs, the growth is induced by Ga atom diffusion at high temperature. The NWs growth at high temperature taperes. That ascribes to lateral growth on NWs sidewalls. It is revealed that crystalline structure of NWs grown at low temperature is pure zinc blende (ZB) and there is no defect in thick NWs. At high temperature, there are many defects in NWs, such as stacking faults and twins.

In order to reduce the shrinkage properties of photopolymer material, a photopolymer doped with Mg(OH)2 nanoparticles is fabricated. By using methylene blue trihydrate as photosensitizer, this material is exposed with laser of 647-nm wavelength. The experimental results show that the shrinkage decreases from 3.2% to 1.6% and the diffraction efficiency increases from 75% to 89% and the maximum refractive index modulation reaches 2.24×10-3 when the photopolymer is doped with Mg(OH)2 nanoparticle. The analog image is stored in the material and the reconstructed hologram is still clear. All of the results demonstrate that the incorporation of Mg(OH)2 nanoparticles can improve the holographic characteristics of photopolymer material.

Coating-induced polarization aberrations of large incident angle are theoretically studied by Jones matrix. The method to reduce the aberrations is proposed through derivation, which is δ=0 and arbitrary incident angle should be appended as two additional optimization goals of optical coating design when the requirements of transmittance are met. Two different anti-reflection coatings which are designed through different optimization goals are compared to further verify the theory. The two anti-reflection coatings represent large and small transmittance and phase difference respectively. Numerical simulation of the two coating induced polarization aberrations is also performed to further verify the theory.

The spatial scanning Raman spectra method is applied in the study of fluid inclusion of carbonate reservoir. Some inclusions of carbonate reservoir are exannined by microscopic confocal Raman spectral methods. In experimental process, X-Y scanning and depth profile(Z scanning) have been finished around the inclusion, with sample temperature of 20℃, -40℃, -80℃ and -170 ℃. Because the size of some inclusions are relatively small or hidden deeply in sample, their Raman spectra signals are often buried in some noises and other disturbing signals which stem from main mineral. The experimental results show that the original experimental spectral curve of the inclusion does not almost distinguish from the original experimental spectral curve of pure main mineral(rock core) when relative large size of confocal pinhole is used. It is found that the number aperture (NA) and the fill factor of objective are important to the performance of lateral resolution, whereas the size of confocal pinhole is critical to the longitudinal resolving ability of microscopic confocal Raman spectroscope.

Leptin and its long form receptor (OB-Rb) were expressed in many tissues including mammary gland. To elucidate the expression location and relative expression quantity of leptin and OB-Rb in different development stage of mouse mammary gland, the expression and localization of leptin and OB-Rb were detected by introducing indirect immunofluorescence and laser scanning confocal microscopy. The images required were analyzed by Image Pro 5.0 Plus and the quantification of leptin and OB-Rb were represented by gray value. The results showed that leptin was detected in mammary fat pad, ductal epithelial cells and acinar epithelial cells. OB-Rb was detected on the basal surface of ductal epithelial cells and acinar epithelial cells. The expression variations of leptin and OB-Rb reached the highest level in virgin, and then decreased in pregnancy. In lactation, the expression of leptin and OB-Rb become lower. After offspring withdrew, the expression of leptin and OB-Rb increased and recovered to the original level of about virgin. The expression quantity of leptin was a little higher than OB-Rb in the whole development cycle. Correlative analysis showed that there was a positive correlation between the expression of leptin and OB-Rb(r=0.941, P≤0.01).

Four psychrophilic bacteria are cultured in the laboratary to resolve the low domestic sewage treatment load at low temperature. Scanning electron microscope is used for observing the morphological feature and biological fluorescence spectroscopy is employed to measure the bioactibity of the four psychrophilic bacteria. The results show that the four bacteria are all from bacillus and have high bioactivity and strong adaptability. The bioactivities of psychrophilic bacteria are higher than those of mesophilic bacteria when the temprature is below 15 ℃. Therefore, it is necessary to add psychrophilic bacteria into domestic sewage to increase the degradation rates since the mesophilic bacteria almost lose their bioactivities when the temperature drops below 15 ℃. The value of the degradation rate is measured and the result shows that the removal ratio of tatal nitrogen increase 53.5% and the removal ratio of tatal phasphoras increases 80% in our experiment by using the mixed psychrophilic bacteria.

Human eyes′ contrast sensitivity function (CSF) at temporal frequencies and wave-front aberrations of optical system of the eye have been measured respectively, and then the neural contrast sensitivity function (NCSF) is calculated by the correlation between them. The results demonstrate that the overall value of NCSF decreases as the temporal frequency increases. From the low to the high temporal frequencies (the testing temporal frequencies of 1~30 cycle/s for two eyes and 1~24 cycle/s for the other two), the relative decreasing amounts of NCSF are: 90%, 87%, 60% and 68%, respectively. Comparing with the corresponding CSF at temporal frequencies, the NCSF curve is smooth at low and middle spatial frequencies [2~10 cycle/(°)] and decreases appreciably at high spatial frequencies [greater than 10 cycle/(°)]. The values of NCSF curves at the same temporal frequency for 4 subjects′ eyes are approximate, which demonstrates that the responding of the human eyes (without optic nerve disease) to the same temporal frequency is identical.

Many factors of intracavity perturbation can degrade output power and beam quality in high power passive Q-switching slab lasers. The experiment test on output beam quality of a passive Q-switching zig-zag slab laser has been performed by adopting Hartmann-Shack (H-S) wavefront sensor and Zernike modal reconstruction theory. In this way, peak value (PV) and root mean square (RMS) values of the wavefront aberration, and Zernike aberration of each order can be acquired accurately. Moreover, distribution of circle energy in far-field, point spread function (PSF) and other beam evaluation factors can also be obtained by further calculation, so the beam quality can be illuminated comprehensively. Results analysis show that the wavefront aberration of beam mainly concentrates in the frontal 10 ranks of Zernike aberration, mainly including the defocus A3, the low-order astigmatism A5, the coma aberration A6 and the spherical aberration A10 because of the crystal thermal effect and intracavity aberrated perturbation.

There are more and more demands for micro integrated filter because of the infrared hyperspectral application. In 1.9~2.4 μm infrared spectrum, 32-channnel integrated infrared filter is designed by changing the thickness of spacer layer and maintaining the basic optical layers the same. The change of the spacer layer can be realized by etching or depositing. Considering the error during fabricating, the spectrum can still meet the requirements. The half power bandwidth is 5~8 nm, the spectrum curve across-points are lower than 15% in transmittance mostly. With the current technique, both the etching and the depositing methods can be used to fabricate the integrated infrared filter.

Utilizing Bulk model based on the Monin-Obukhov similarity (MOS) theory, the spatial and temporal distribution of atmospheric turbulence in marine surface layer of China Sea is analyzed based on the routine meteorologic factors of South and East China Sea. A program is compiled to realize the function in estimating atmospheric turbulence in marine surface layer. The input data is the routine meteorologic factors from the district of 10° to 33° north latitude and 110° to 130° east longitude, based on the data published by China Meteorological Administration. The routire meteorologic factors consist of water temperature, air temperature at height z, water vapor density adjacent to the sea surface, average water vapor density at height z, air pressure and the average wind speed. The panoramic image of atmospheric turbulence in marine surface layer of China Sea (independent to time) is established utilizing the algorithm of estimating refractive index based on the mean field of the several years meteorologic factors. Then by making a statistic on the air-sea temperature difference (ASTD) by month, we can get two sets of fluctuation data of ASTD on 2D spatial various observation points in East China sea and South China Sea, each of which has 12 groups because the data analyzed is from different districts in the South China Sea and East China Sea. The fluctuation of ASTD is deemed as the key index to depict the seasonal rule or temporal distribution of atmospheric turbulence in marine surface layer. The spatial distribution of atmospheric turbulence is also discussed in the month that has the maximum or minimum variance of ASTD, since it is denoted as the dispersion index. The difference of atmospheric turbulence between seacoast and mare liberum is also discussed while the location is taken into account, thus the spatial distribution of atmospheric turbulence in marine surface layer of China Sea is brought forward.

The longitudinal distributions of beam in resonators always change with the focal length of thermal lens. Therefore, most of fundamental mode laser output from laser diode-side-pumped modules are usually obtained at given pump powers. The resonator model with thermal lens and the condition for fundamental mode operation are studied. The relation between the fundamental-mode spot at crystal and the focus of thermal lens is calculated, and the resonator is designed for dynamic fundamental-mode operation. At repletion rate of 10 kHz, the laser operates with dynamic fundamental mode and the average power can be obtained from threshold to 17.7 W, M2x=1.29 and M2y=1.20. Pulse duration is measured to be 200 ns and the peak power is 7.65 kW.

With Cr:YAG as saturable absorber and output coupler, passively Q-switched microchip laser was obtained for laser diode (LD) end-pumped Nd:LuVO4 crystal. When the pump power was 13.86 W, a maximum average output power of 0.508 W was obtained, corresponding to an optical conversion efficiency of 3.6%, and a slope efficiency of 8.3%. The highest repetition rate, largest pulse energy and shortest pulse width were measured to be 23.95 kHz, 21.21 μJ, and 4.5 ns, respectively, corresponding to a peak power of 4.71 kW.

Based on the characteristics of small radar cross section, high speed of air moving target, the existing condition of shitty target detection effect and low detection efficiency of those conventional radar and infrared means, a new algorithm of acquiring air moving target information based on wind field disturbance detected by lidar is proposed. The basic principle and main process of moving target information acquisition based on wind field disturbance is given. Through receiving the laser echo signal reflected by atmosphere and the retrieval algorithm of radial and horizontal wind speed, the wind field distribution in scanning area can be acquired. Meanwhile, the disturbance wind field can be acquired by filtering background wind field, the location and attribute of target can also be obtained based on the moving target information acquisition algorithm. The experimental result shows that the target location is the radial distance of 800 m and the pitching angle of 82°drawn by this algorithm is the same as the practical situation. Consequently, this new means of target detection is practicable, which will offer a brand-new path of detecting and discovering air moving target efficiently in the future.

MOCVD epitaxial P-GaN, which was grown on the sapphire substrate and AlN buffering layer, was used to make photocathode by ultra-high vacuum preparation technique. The quantum efficiency properties of prepared GaN photocathode under reflection mode and the transmission mode measured and analyzed by UV spectral response testing instrument. Experimental results showed that the sample in reflection mode has up to 50% quantum efficiency at 240 nm, but in transmission mode, the maximum quantum efficiency is only 15%. Curve fitting results of experimental quantum efficiency revealed that sample′s back interface recombination velocity is about 104 cm/s. It was also found that the reasons for the great difference in this two operating modes were back-interface recombination velocity and the thickness of GaN epitaxial materials.

Assuming atmospheric molecules extinction coefficient is known, a new method for retrieving aerosol extinction coefficient with pure aerosol echoes is proposed. The pure aerosol echoes are reconstructed with rotational Raman echoes and Mie echoes detected with a rotational Raman-Mie scattering lidar (RRML). Assuming the extinction backscattering ratio is an approximate constant, an integral formula for aerosol extinction coefficient inversion is derived. In the method, the Rayleigh backscattering signal included in the Mie echo is removed to reduce the impact of fluctuation of atmospheric molecules. Finally, the new method is applied to the RRML echo detectinon by the RRML developed by ourselves. The results showe that stable aerosol extinction coefficient profile could be retrieved effectively by using the new method.