In dense wavelength division multiplexing systems, the light sources are difficult to be synchronized and costly. A structure of multi-carrier light source with good flatness, large number of subcarriers, large spectrum width and adjustable frequency spacing was proposed which can be used in dense wavelength division multiplexing systems. The structure is cascaded with a Mach-Zehnder modulator , an electro-absorption modulator and a phase modulator . In the structure, all the modulators can be driven by a sinusoidal signal to obtain multiple sub-carriers with low flatness and adjustable frequency spacing. When the driving signal frequency is 9 GHz and 12.5 GHz, the number of subcarriers is 31, the flatness of the generated multi-carrier light source can reach 0.09 dB. When the driving signal frequency is turned from 3 GHz to 16 GHz, the number of generated subcarriers is almost unchanged, and the flatness of the subcarriers is always less than 0.15 dB under the condition of 31 subcarriers. And when the driving signal frequency is 16 GHz, the spectrum width of the obtained multi-carrier light source can reach 480 GHz. In addition, the influence of the parameters, such as the upper and lower arm bias voltages of Mach-Zehnder modulator, the chirp factor and the modulation index of electro-absorption modulator, are analyzed with the performance of the system, such as the number of subcarriers, the spectrum width of the generated multi-carrier light source.

A demodulation algorithm based on all-phase filters was proposed for fiber Bragg grating noise reduction. The all-phase filter can configure the filter coefficients rapidly and flexibly according to the frequency characteristics of the fiber Bragg grating signal, which can effectively filter out the high-frequency components mixed in the original signal by controlling the filter boundary adaptively. The analytical expression of the filter was deduced, and the amplitude-frequency characteristics of the filter was analyzed with the digital frequency characteristics of fiber Bragg grating signals. The experimental results show that the proposed filtering algorithm has an adaptive performance in processing fiber Bragg grating signals at different sampling intervals. This algorithm has a similar wavelength stability compared with the Gaussian fitting method, but the average demodulation time is shortened by 10 times. The wavelength demodulation stability is improved by 30% compared with the centroid method.

A temperature-controlled liquid crystal filling photonic crystal fiber was designed. The dispersion compensation characteristics of photonic crystal fiber were numerically simulated by using the finite element method. The effects of various structural parameters on the photonic crystal fiber dispersion were theoretically analyzed. And the structure parameters were adjusted. By adjusting the liquid crystal′s refractive index, dispersion compensation location can be precisely adjusted to 1 550 nm, the peak of negative dispersion is －426 000 ps·nm－1·km－1. A 2-meter-long designed fiber can compensate a 50 000-meter-long standard single-mode fiber (G652). The simulation results show that the dispersion compensation wavelength changes with the effective refractive index of the filled LC, and it might be quantitatively controlled by the temperature adjustment in the wavelength range from 1 533 nm to 1 552 nm.

Based on the model of ultraviolet communication transmission, the absorption and scattering characteristics of ultraviolet communication were analyzed based on the Mie scattering and Rayleigh scattering theory. The impact of different path loss and bit error rate were simulated on the basis of Monte Carlo method under the condition of fine weather, severe fog and haze weather, extremely severe fog and haze weather. Using a 255nm ultraviolet LED as the light source, a photomultiplier as the receiving device and a 10 kHz and 100 kHz square wave signal as the transmitting signal, outdoor short distance ultraviolet communication experiment under three different weather conditions were performed. The experimental results indicate that under the condition of communication distance less than 100 m, with the increasing of fog and haze pollution, the path loss of line-of-sight ultraviolet communication increases gradually, and the path loss of non-line-of-sight ultraviolet communication decreases gradually. In non-line-of-sight ultraviolet communication, when the transmitting power is 0.6 mW, the transmitting and receiving elevation angles are less than 20° and the communication distance is less than 40 m, the communication quality is relatively better.

A theory for magnetic-temperature coupling effect generated in a Fiber Optic Gyroscope (FOG) under the combined action of magnetic and temperature fields was proposed. The magnetic-temperature coupling in FOG originates from the interaction of the magnetic field, fiber twist, birefringence caused by thermal stress, and the intrinsic and bending birefringence of the fiber. The cross-coupling changes with temperature. When the polarization maintaining fiber has a diameter of 250 μm, beat length of 3 mm, length of 1 600 m, twist rate of 1 rad/m, and optical source wave length of 1550 nm, the maxim degree of magnetic-thermal coupling generated by a 1 mT radial magnetic field within the temperature range of 20℃ to 60℃ is 6.796%.

This paper is aiming at jointly optimizing the design and analysis of the optics and digital image processing for imaging systems. The influence of each aberration on the imaging sharpness is analyzed according to the Zernike polynomial model. A digital image processing algorithm is proposed for aberration correction, which is based on the variational bayesian framework and weighted bi-direction difference prior. Then the aberrations are divided into two categories: easy to digital correct and hard to digital correct, so an optics-digital processing co-design method can be established based aberration optional-correction. At last, a three-lens large aberration optical system is designed by the co-design method, its MTF value at the nyquist frequency is about 0.50; in contrast, a six-lens system is designed by traditional method, and its MTF value is about 0.53. These results show that the imaging quality of two system is similar, therefore, the proposed method would be capable of reducing the complexity of the optical system.

Based on the clinical available wavefront aberrations of human eye, corneal topography and axial data, 60 individualized eye models were constructed in the optical software Zemax, with which the ingoing wavefront aberrations and outgoing wavefront aberrations under the pupil diameter of 6 mm and of 3 mm were obtained. When the pupil diameter is 6 mm, the ingoing wavefront aberrations and outgoing wavefront aberrations are 3.753 μm and 3.074 μm, respectively, showing a statistically significant difference(p<0.05). The difference of defocus between the ingoing wavefront aberrations and outgoing wavefront aberrations is 1.131μm, which is accounting for 82% of the whole difference. The difference of spherical aberration between the ingoing wavefront aberrations and outgoing wavefront aberrations is 0.185 μm, which contributes 13% of the total difference. Except for higher-order aberrations, the differences in defocus, astigmatism, coma and spherical aberration are statistically different in 6 mm pupil. When the pupil diameter is 3 mm, the ingoing wavefront aberrations and the outgoing wavefront aberrations are 0.804 μm and 0.732 μm, respectively, which difference is statistically significant (p<0.05). The difference in defocus is 0.133 μm, which is accounting for 80% of the total difference. Except for astigmatism, difference in defocus, coma, spherical aberration and higher-order aberrations are statistically different. The results of this study show that the difference between the ingoing wavefront aberrations and the outgoing wavefront aberrations of the human eye is statistically significant, both for large pupil and for small pupil.

The intersection issues between the reflected light and the incident light are transformd into the intersection problems between the reflected light and the plane containing the incident light, and the line-plane model is constructed. The point light source is used to replace the traditional continuous surface light source, and the incident light plane is determined by detecting the projected lights of two or more light source points on the incident light. Then the mirror point is determined by the intersection between the reflected light and the incident light plane. The calibration method for line-plane deflectometry is proposed on the basis of the mirror calibration method, which can be used for specular measurement with only once calibration. The effect of the posed relationship on reconstruction accuracy of the system is analyzed in simulations. The maximum error of system measurement is 0.25 mm, the root mean square error is 0.073 mm. Experiments verify the feasibility of the proposed methods, and the experimental results show that the method has high accuracy.

Aiming at the need of high-precision detection of aeroengine blade profile, the 3D reconstruction technology of blade profile based on laser scanning point cloud was described, and the error of profile reconstruction was analyzed. The measurement data was processed through the mathematical model of point → line → surface. First, the smoothing curve is fitted by the first-order end-point vector method of point cloud, then the Non-Uniform Rational B-Splines surface is fitted based on the section curve, smooth surface method is used to reconstruct the surface, and the reconstruction error is analysised by calculating the minimum distance between the space measuring point and the surface. Finally, the algorithm is verified by the blade profile laser measuring device. The experimental results show that the reconstruction error is less than 0.015 mm, which meets the evaluation requirements of blade profile quality.

The digital holographic measurement method and the diffraction propagation algorithm of variable sampling interval were proposed to realize the fine measurement of the focal length and focal spot of the photon sieve. The bifocal photon sieve and its theoretical focal spot distribution were presented. The double-exposure off-axis holographic method was used to obtain the complex amplitude distribution of the light field at the CCD. Based on the light field, the focusing field characteristics of bifocal photon sieves with higher resolution were obtained through the diffraction propagation algorithm of variable sampling interval.The resolution of the focal spot is about 10times that of the direct measurement by CCD. The focal length is equal to the sum of the two distances obtained by the autofocus algorithm and the intensity maximum scanning method respectively. The experimental results show that the deviations between the measured bifocal lengths and the designed focal lengths are 0.53% and 0.37% ,respectively. Compared with the full-width at half-maximum of Greek-ladder photon sieve as required, the measured width of the two focal spots is accurate enough with error of 2.86% and 1.86%, respectively. The measurement method proposed in this paper can be widely applied to the measurement and performance analysis of other diffractive lens focusing characteristics besides the performance testing of photon sieves.

With a LiNbO3 crystal as the electro-optic Q-switch, a compact Q-switched laser with a high repetition rate and a narrow pulse width was developed. The crystal was sandwiched between two crossed polarizers, then the variation of the laser transmitted intensity with the pulsed high voltage applied to the crystal was measured to investigate the piezoelectric ringing effects in LiNbO3 crystals with different dimensions. Additionally, the piezoelectric ringing effects in LiNbO3 crystals were compared with that of a RbTiOPO4 crystal. The results show that the block LiNbO3 crystal suffers enormously from piezoelectric ringing, while the piezoelectric ringing in the miniaturized LiNbO3 crystal is similar to that of the RbTiOPO4 crystal and is negligible. Combining with the piezoelectric effect theory, it is derived that the acoustic ringing is influenced by the applied voltage and the piezoelectric resonance frequency, the acoustic ringing decreases with the decreasing of applied voltage and the increasing of piezoelectric resonance frequency. Based on these results, a miniaturized LN electro-optic Q-switch that can operate at a high repetition rate was prepared, its dimensions is 1.2 mm×9 mm×9.4 mm. The miniature LN crystal was successfully used for high repetition rate electro-optic Q-switching. A Nd∶YVO4 crystal possessing a large emission cross-section and a short fluorescence lifetime was used as the gain medium. One side of the Nd∶YVO4 crystal was high-reflection coated at 1 064 nm, and another side was cut along the Brewster angle, then a reflecting mirror and a polarizer was saved and the cavity length was shortened. The pump source was a fiber-coupled laser diode with a central wavelength of 808 nm. Based on the above design, a compact cavity with a length of only 20 mm was achieved. In the pulse-off Q-switching operation, a stable pulsed laser operating at a maximum repetition rate of 15 kHz with a pulse width of 5.4 ns and a peak power of 2.94 kW was obtained.

An active-passive double Q-switched 946 nm laser was reported which with a double 45° cut-magnesium oxide doped LiNbO3 electro-optic crystal and a monolayer molybdenum selenide saturable absorber. In order to obtain 946 nm laser pulses with high energy and high peak power, a pulsed laser diode side-pumped long Nd∶ YAG rod is used as the gain medium in a folded biconcave cavity. Output pulses with maximum pulse energy and peak power up to 3.15 mJ and 346 kW were obtained, corresponding to 550 Hz repetition rate and 9.1 ns pulse duration at 946 nm. Peak to peak instabilities of pulse width and pulse energy were ±2.87% and ±3.42%, beam quality factors were Ｍ2x＝3.851 and Ｍ2y＝3.870.

Based on theoretical calculation of the stored energy and small-signal gain coefficient of the travelling wave amplifier, the characteristics of the output laser were simulated. With the increment of the pumping current, the stored energy and small signal gain coefficient increase rapidly. And amplifier energy extraction efficiency can reach more than 76%. In terms of the output energy, it rises linearly with the increasing of the pumping current. When the pumping current is 80 A, a 798 mJ laser pulse can be obtained. Related experiment is carried out on the basis of theoretical simulation. In this experiment, a pulse with 350 mJ energy, 10 Hz repetition frequency, 10 ns width is used as the seed. The size of the Nd∶YAG crystal rod in amplifier is Φ7 mm×134 mm and the doping concentration is 1.1 at%. The maximum peak power of laser diode (LD) is 24 kW. In order to control the temperature of the crystal working environment, three thermoelectric coolers are chosen with a maximum power of 66 W. Ultimately, a 700 mJ, 10 ns, 10 Hz laser pulse is obtained for single-pass amplification. The beam qualities of horizontal and vertical direction are 7.9 and 12.4, respectively, measured by the beam quality diagnostic instrument M-200S.

Dynamical characteristics of a monolithically integrated semiconductor laser have been experimentally studied. The laser consists of a distributed feedback semiconductor laser section, a phase controlling section and a semiconductor optical amplifier section. Using a general analysis method of dynamics, we have experimentally investigated the bifurcation route to chaos and the dynamical characteristics of intermittent chaos through the optical spectra, time series, phase portraits and power spectra of the laser. The results show that, under suitable operating parameters, the monolithically integrated semiconductor laser can be driven into intermittent chaos oscillation characterized by the chaotic state stochastically interrupted by the stable state. For fixing the currents of distributed feedback semiconductor laser section and semiconductor optical amplifier section and gradually increasing the current of the phase controlling section IP, the monolithically integrated semiconductor laser successively undergoes stable state, period one, intermittent chaos, and returns to stable state. The range of IP required for achieving intermittent chaos oscillation is determined. Moreover, the evolution of the average laminar time with the increase of IP has been analyzed, and the result shows that, with the increase of IP, the average laminar time decreases firstly, after reaches a minimum, and then rapidly rises.

According to the temperature tunability of chirped fiber grating, a new kind of dispersion compensation method was proposed, which make chirp fiber grating in a continuous linear temperature gradient field. The dispersion of chirped fiber Bragg grating is fine-tuned by adjusting temperature difference between the ends of the fiber Bragg grating. The dispersion mismatch in chirped pulse amplification system, which is based on the chirped fiber Bragg grating as pulse stretcher and chirped volume Bragg grating as pulse compressor, can be continuously compensated, and the feasibility of this method is verified by experiment. The experimental results show that the application fields, when the temperature difference of the continuous temperature gradient along the chirped fiber Bragg grating continuously changes from 0℃ to 50℃, the dispersion mismatch between the stretcher and compressor can be continuously adjusted, thereby eliminating the tedious pulse width optimization steps. The gradient of the continuous linear temperature field is reported for the first time to fine-tune the dispersion mismatch in chirped pulse amplification system that uses the chirped fiber Bragg grating as pulse stretcher and chirped volume Bragg grating as pulse compressor.

The samples of Er3+ and Eu3+ co-doped GaN epitaxial films were prepared by ion implantation technique. Their optical properties and energy transfer mechanism were investigated using cathodoluminescence. For Er3+ and Eu3+ co-doped GaN films sample, the mixed color of green and red light can be realized at 300 K. Moreover, the emission intensity of Eu3+ ions and intensity ratio of Er3+ ions were decreased with the increase of Er3+ ions implantation dose, which proved the existence of the energy transfer from Eu3+ to Er3+ in the GaN host. The result of temperature-dependent cathodoluminescence spectra shows that the intensity ratio is decreased with the temperature increasing, which indicates there is a thermal coupling of 2H11/2 and 4S3/2 states of Er3+ ions. The calculated chromaticity coordinates and color correlated temperature can be tuned through adjusting the implantation dose ratio of Er3+ to Eu3+. This work shows Er3+ and Eu3+ co-doped GaN films are promising materials applied in optical devices.

In order to study the stability of graphene transparent conductive film under light irradiation and the mechanism of its stability change, the electrical conductivity of graphene under different atmosphere, wavelength and power density of visible light irradiation were introduced. Results show that resistance of graphene film increase slowly under irradiation, and decrease after light off. The resistance of graphene film is most stable under nitrogen, and most unstable under vacuum. Under the irradiation of red light with the same power density, the relative resistance changes of samples under nitrogen, air and vacuum is 0.09%, 0.22% and 0.4% respectively. In the same environment, the shorter the wavelength, the higher the photon energy of the light source has the greater impact on the samples. In the atmosphere, with the same power density, the relative resistance of the sample changes 20% under blue light, compared to 3% for green and 0.22% for red.

In order to obtain high-performance flexible transparent conductive thin films, STO (30 nm)/Ag/STO (30 nm) multilayer thin films were prepared on PC substrates by magnetron sputtering. The influences of Ag mid-layer thickness on the structure, optical and electrical properties of the multilayer thin films were investigated. As the thickness of Ag mid-layer increases, the average transmittance in visible region firstly increases and then decreases, both the resistivity and sheet resistance decrease. For the multilayer thin films with 11 nm thick Ag mid-layer, it exhibits the maximum figure of merit of 14.23×10－3 Ω－1 with sheet resistance of 9.2 Ω/sq., and the average transmittance is ~82 % in the visible light region.

Based on research idea of Quantitative Structure-Property Relationship, parameters of physicochemical properties refractive index and density as well as the structure parameter molar refraction were correlated with the component parameter boron content, the relationship between material structure, composition and property was responsed by a mathematical model to calculate the boron content of boron doped stress application preform. For boron doped stress application preform, molar refraction of B2O3 and SiO2 was calcuated by the experimental results are 10.546 13 and 7.373 32, respectively. The simulation model and caculated results were verified by experimental data. The relative errors of boron content between calculated values and measured values are within 0.5%. The results show that the precision of simulation model is high enough to meet the industrial production demand for estimating the boron content of boron doped stress application preform.

The transmissivity and conductivity of the few-layer graphene with 600 nm CW laser and two substrates are measured and analyzed, based on terahertz time-domain spectroscopy and the Drude model. In this study, the absorption of terahertz signal is obviously enhanced through the graphene on high-resistivity silicon or the absorption of terahertz signal is slightly decreased through the graphene on PET (Polyethylene terephthalate) with the excitation of external laser. At 0.5 THz, the conductivity of the graphene on high-resistivity silicon is increased by 7 times or the conductivity of the graphene on PET is felled to 77%, compared to that without external laser. Meanwhile the experiments verify that the conductance in the few-layer graphene appears as the linear superposition of per layer among the THz waveband.

Extinction enhancement of GaSb nanowire because of Au nano antenna is studied based on finite difference time domain method. The electric field property and optical property of Au nano antenna array with different shapes are analyzed, it is found that triangular is the best structure, which possesses the resonant absorption peak with high intensity and the electric field with high enhancement factor. Then, the engineering of size and gap with nanowire of triangular structure is performed. Adjusting the triangular size and the gap of nanowire respectively, the results show that the corresponding extinction peak increases from 783 nm to 1638 nm monotonously with the size increasing from 70 nm to 210 nm, and the intensity and enhancement factor of electric field are enhanced. The size of 200 nm is six times the enhancement factor of 70 nm; Increasing the gap from 80 nm to 130 nm, the corresponding extinction peak decreases from 1655 nm to 1460 nm, with lightly weaken intensity and enhancement factor of electric field. So the optimal approach of tuning the size after the determined gap is appeared for the design of Au nano antenna structure.

By measuring the distribution of impurity Zn in InP of planar-type InGaAs/InP Geiger mode Avalanche Photodiodes,the function of doping concentration with diffusion depth was fitted, and the optimum depth of etch well at different multiplication layer thickness as well as the best etching method were studied using ionization integral.The results show that the optimum etch well depth is varied with multiplication layer thickness when the thickness of top InP is constant.And when the multiplication layer thickness is about 1 μm, the well depth should be between 0.1 μm and 0.3 μm. Reactive ion etching can obtain a good etch well morphology, which is beneficial to the suppression of edge breakdown.

A theoretical model of Ag/Au micro and nano structure was established based on the optical near-field excitation and the local field theory by optical simulation software. The new structure of polymer/fullerene solar cells based on the perfect absorber are demonstrated by high resolution lithography technology, and the perfect all-optical wavelength absorption of the solar spectrum from the ultraviolet to near-infrared light is achieved in order to improve energy conversion efficiency of solar cells. At the same time, the new donor materials was designed and prepared which have similar structure, good "compatibility" and complementary absorption spectrum. The ternary solar cells were prepared which fabricated with two polymers as the electron donors blended with fullerene acceptor to maximize the matching of the solar spectrum. This method can effectively improve the response of the device to the sunlight, produce a large number of optical carriers, and greatly improve the short circuit current density and the open circuit voltage. Then the new polymer solar cells with high efficiency and high stability are expected.

A tunable gradual changed Slotted Photonic Crystal Waveguide (S-PCW) was demonstrated based on subwavelength particle controller for vacuum environment. Particles can be trapped in slot structure and transported along the light transmission direction. Through thermal-optic tuning the gradual changed S-PCW, particles can be transported to the desired position. The bandgap structure and transmission characteristics of the S-PCW were analyzed, as well as the optical force with the particle. The simulation results on the power consumption of the thermal control and the temperature distribution in S-PCW show that the particle transportation in a gradual changed silicon S-PCW can be achieved through thermal-tuning the refractive index of silicon material. The calculated refractive index shift is 0.012 for position control in a 18 μm-long S-PCW with 4 nm slot width shift fron input port to output port, which corresponding to a 13.7 mW heating power. The compact device footprint shows the potential of the controller for micro manipulating applications.

It is found that the resolution of the striations is reduced from the center to the edge. In order to improve the edge spatial resolution of the streak, the compression sensing is applied to the X-ray streak camera imaging system. The compressed sensing reconstruction model is constructed for the streak camera, the compressed sensing objective function is implemented by orthogonal matching method, and the reconstruction parameters are optimized. After the original image is compared with the reconstructed image, the result shows that the contrast ratio of the compressed sensing reconstruction is 5% higher than the original; the limit resolution is 2lp/mm higher than the original image, furthermore, the improvement effect far from the central area is better than that of the central area. The compressed sensing reconstruction can improve image contrast ratio on the edge of image, thus, the static spatial resolution of the image is improved.

A Hexagonal Close-packed Multi-lamination-layer Carbon Nanotube (HCP-MLL-CNT) cathode is proposed. In this scheme, the silver slurry is sintered to form the substrate silver electrode with a hexagon-shaped edge, which is fabricated on the transparent indium-tin-oxide electrode, with a staggered arrangement of the adjacent substrate silver electrode on the cathode faceplate. Using ZnO and SnO2 powders as mixing materials, the base blending layer is formed between the substrate silver electrode and the single CNT layer, whereas the CNTs in single CNT layers are mainly utilized to emit the cathode electrons. The fabrication process of an HCP-MLL-CNT cathode is discussed in detail, and and the feasibility study which the HCP-MLL-CNT cathode is applicable as an electron source is performed. The sintering method, in which the nitrogen gas is used as a protective gas, was adopted to remove the organic binder materials and other organic impurities of the preparation slurry. The HCP-MLL-CNT cathode was vacuum-sealed into the triode field emission display, and a stable electron emission current was formed. The measurement results indicate that the proposed HCP-MLL-CNT cathode possesses the enhanced electron emission characteristics, a low turn-on electric field of 1.83 V/μm, and the increased maximum electron emission current of 2718.6 μA. The HCP-MLL-CNT cathode revealed an excellent electron emission curve trend, in which the increasing range of electron emission current was approx. 1410.3 μA for the electric field enhancement range from 2.17 V/μm to 3.06 V/μm. The fluctuation of the electron emission current with time was also measured, and a reliable and stabile electron emission for HCP-MLL-CNT cathode was experimentally verified. The green emission image was displayed, which corroborated a good electron emission uniformity and high electron emission luminance of the proposed HCP-MLL-CNT cathode. It is shown that a simple fabrication structure and manufacturing process of the proposed HCP-MLL-CNT cathode possesses a high potential for practical applications.

An integrated spectral micro-module with a linear variable filter and an InGaAs focal plane array was proposed. As the core light dispersing element, the linear variable filter was coupled with an InGaAs detector array. Compared with the grating spectrometer, the micro-module has compact structure and stable optical properties. The wavelength calibration method and its accuracy were proposed and validated experimentally. The spectral range of the module is from about 900 nm to 1 700 nm. The calibration accuracy is better than 1.3 nm and the spectral resolution is no larger than 1.25% of peak wavelength. Experimental results demonstrate that the method of wavelength calibration is feasible and accurate. The spectral micro-module can be widely used in field or on-line applications.