Soft gain aperture effect from pump beam size inside the laser crystal is crucial for obtaining stable Kerr lens mode-locking and generating ultrabroad-bandwidth pulses in Ti∶sapphire laser. Modelocking dynamics is experimentally investigated for a diode-pumped all-solid-state laser. At the pump power of 4 W,the femtosecond laser pulses tunable from 794 nm to 835 nm are generated with high output power of 570mW and extremely large bandwidths at the maximum of 135 nm,which can support the transform-limited pulse width in sub-10 fs time duration. Moreover,this laser is extended to blue pulses tunable from 418 nm to 429 nm by using a 260 μm-thick BBO crystal.The measured ultrabroad bandwidths are unprecedent in this spectral region,and their transformlimited pulse durations are sub-15 fs.

The leaky spectrum of Photonic crystal fibers (PCF) was simulated with beam propagation method. The results showed that the leaky spectrum usually had several bandgaps,which would provide theoretical reference for designing a novel multi-band filter. Furthermore,the leaky spectrum was very sensitive to the PCF structure,the spectrum was affected not only by the period of the air hole but also by its dimension. Finally,the liquid crystal (LC) could be infiltrated in the air holes of the PCF,because the refractive index of LC could be tuned by controlling the voltage and the temperature. The peak leaky wavelength and bandgap wavelength would red shift with the LC refractive index increasing,which would provide reference for designing a novel tunable filter and optical switch by controlling the voltage or tune the LC temperature.

Based on the theory of matrix optics,temperature effect of Ring Laser with the Total Reflection Prisms (TRPRL) is studied. A 3×3 transformation matrix of optic system with the variation of refractive index is investigated theoretically. A deflection model of ray in resonator for the variation of refractive index is established. The regular pattern of deflection in the TRPRL caused by temperature shift is discussed. The method of reducing the influence of temperature effect is studied. These conclusions have important purposes in design and application of the TRPRL.

Generally,the energy density distribution of a TEA CO2 laser was flat-topped. In order to find a new method for studying and analyzing the output beams of TEA CO2 lasers,according to the FGB theory,the energy density distribution of the measured flat-top beam output by a TEA CO2 laser was expanded in Hermit-Gauss functions. And the space distribution characteristics of the output beam were analyzed and investigated. It was proven that the energy density distribution of a TEA CO2 laser could be expanded in Hermit-Gauss functions.

The plume photograph from laser ablation of metal Cu in different Ar pressure was taken,and it has different colour in different region. The effect of pressure over 265 kPa-98.2 kPa on plume colour was studied. Spatial-resolved spectral measurment technique was used to study the spatial emission intensity distributions of plume by pulsed laser ablation of metal Cu in different pressure. The excimer dynamics of laser ablation of Cu surface was studied,the microscopic excimer mechanism of laser laser ablation of Cu surface was discussed. The results show that the plume may be explained using a simple model based on plume is made of three region,the region ablation mechanism is different from one another,the excited Cu atoms and Cu ions may be produced from different mechanism. The model can be used to explain the experimental results qualitatively.

The five mirror cavity of diode pumped Yb ∶YAG Kerr-lens mode-locked laser was analyzed theoretically in this paper. To get stable self-mode-locking in the experiment,the best parameters of the cavity had to be found. Compared the five mirror cavity with the four mirror cavity,it was found that the mode-locking was much more stable in the five mirror cavity. The reasonable explanation of five mirror cavity stable mode-locking was given in this paper by using stability region theory. And the Kerr-strength of the five-mirror cavity was calculated. It would provide a theoretical method for the modulation of the diode pumped kerr-lens mode-locked laser.

A magneto-optical-modulating-double-frequency system is set up and actualized with temperature controlled added. The eigen rotation and Verdet constant of the paramagnetic terbium glass Tb20 are measured in 293K～343K. With the temperature goes higher,the eigen rotation increases to a stable value gradually and the Verdet constant decreases keeping to the theoretical formula. The experimental results show that the terbium glass has sensitive temperature response. When it is used,especially used as Zero-Lock gyro Faraday bias element,temperature compensation must be taken,and several potential approaches to temperature compensation are also given.

By means of two dimension beam propagation method (2D-BPM) with high order Pade approximation,behaviors of SOI waveguide based bend intersections with variant bending radius are simulated and analized. The result shows that crosstalk of intersections decreases with the increase of bending radius and intersecting angle. Furthermore,loss and crosstalk characteristics of bend intersections formed by sine bend,cosine bend and arc bend are compared. Sine bend based structures are proved that it can present lowest loss and smallest crosstalk properties among the three and may find their wide application in the design of bend intersections and other more complicated photonic devices and circuits.

Optical Waveguide Array (OWA) was the key parts of Optical Waveguide Array Electro-Optic Scanner (OWAEOS). Propagation and output characteristics of OWA were studied in the finite-difference beam-propagation method (FD-BPM). Effect of structure parameters of OWA on propagation and output characteristics was analyzed. These results showed that core layer thickness,period,length and number of optical waveguide of OWA were of great effect on amplitude and phase distribution on output section and on the full width at half-maximum (FWHM) of main lobe of output beam. By comparing these results with what were obtained in other methods,the FD-BPM was more convenient and comprehensive to describe propagation and output characteristics of OWA. In addition,scanning characteristics of OWA were studied. Then according to the demand of beam scanning,the optimal structure scheme of OWA is presented.

Laser-fused fiber taper optical coupler features a significantly smaller package in comparison with conventional flame fused coupler and was ready to fit in modern compact devices. An algorithm was proposed for the design of the microcoupler and a 3 dB microcoupler with a fused length 200 μm was presented. As an effort to search for optimal low loss coupling,optical properties of the micro-coupler were studied for various taper lengths from 1000 to 6000 μm as well as for different diameters in coupling region. Beam Propagation Method (BPM) was used to simulate the operation of microcoupler and the theoretical result was compared with measured property. An optimum design was found at a taper length of about 1320 μm and coupling diameter of 14 μm with an excellent coupling efficiency.

A multimode interference (MMI) coupler with the exponentially tapered multimode waveguide is proposed in order to reduce the scale of the MMI device. The relation between the length of the multimode waveguide and the parameters of the tapered structure was analyzed in theory. Compared with the parabolically tapered structure,which has been successfully used in the MMI devices,this structure could further reduce the length of the MMI devices. The results of the simulation by the wide-angle finite difference beam propagation method (FD-BPM) for some MMI couplers with different parameters were given. It was shown that the performance of the MMI couplers with the exponentially tapered structure was similar to the devices with the parabolically tapered structure. As a result,the exponentially tapered structure can be used in MMI devices to reduce the length of this kind of devices.

An optimizing method of main structure parameters (e. g.,the thickness of the crystal) and writing conditions (e. g.,the incident angle) is presented for a holographic grating wavelength division demultiplexer based on photorefractive LiNbO3 crystals. The key performance parameters of the demultiplexer,such as the loss and the polarization dependent loss (PDL),are optimized by selecting favourite structure parameters using a rigorous coupled wave analysis method. Numerical results show that a low loss and a low PDL can be achieved by using the optimal crystal thickness and incident angle. The designed demultiplexer obtains the favourite synthetical performance for an actual application. The experimental method of the grating recorded is also introduced in the present paper. The experimental results accorded with theoretical computation commendably by testing the three different specimens.

The thermally-induced misalignment of fiber collimators in laser packaging of optical module under accelerated temperature cycle testing has been studied both experimentally and numerically. Two types of laser welding clips for fiber/fiber collimator,the saddle-shaped and the arch-shaped were employed in the testing. Experimental results showed that the fiber angular misalignment when using saddle-shaped clip is up to 0.023°after undergoing 10 temperature cycles,whereas the misalignment of arch-shaped is 0.01°,about tw two times less than that of the saddle-shaped. A nonlinear thermal-elasticity coupled finiteelement analysis (FEA)has also been utilized to analyze the properties of residual stresses and consequent angular misalignment of collimators. Experimental measurements of the collimator angular misalignment were in a good agreement with the FEA calculated results. The saturated thermally induced angular shift was calculated to be 0.043° for arch-shaped clip in comparison with 0.065° for saddle-shaped clip,and Von Mises stresses were also presented for the both kinds of clips. It was concluded that arch-shaped clip exhibits a 50% higher thermal stability in optical module packaging.

PAL (Panoramic Annular Lens) was a hemispheric panoramic imaging system based on the principle of FCP(Plat Cylinder Perspective),field range of 360° around the optical axis could be imaged into a annular plane without any kinds of rotatable parts. The image was distorted,thus it was necessary to correct the deviation. An algorithm of correcting the image of a two-dimensional plane was provided based on the principle of FCP,after being treated by radical and tangential linear processes,image of the plane could be corrected into its former shape.

A Sc* ferroelectric liquid crystal with the N*-Sc* phase sequence was used. Through controlling the frequency and amplitude of the applying voltage during the N*-Sc* phase transition,the display of various molecular layer alignments was prepared and the V shaped or half V shaped electro-optical character with continuous gray scale was realized. Based upon the interacting theory between the spontaneous polarization and the torque of electric field,the reason for the alignment frame of different molecular layers of the display,the V shaped and half V shaped electro-optical character was analyzed.

Sampling of photoelectric imaging system could infinitely replicate the scene spectrum in spectrum space. If the sampling intervals were too large to satisfy the Nyquist criterion,the replicas would be overlapped and there was aliasing. The optical transfer function could demonstrate that how the optical imaging,integral sampling and reconstruction affected the overall performance. The optical transfer function was used for analysis of the photoelectric imaging system with OLPF. The results show that optic low-pass filter could effectively limit the scene spectrum width and critically satisfy Nyquist sampling condition,so the aliasing could be eliminated and quality of the image reconstructed is improved.

The reflection effect of the spherical surface of a hemisphere solid immersion lens (SIL) has been investigated using the vectorial diffraction theory for high numerical aperture systems. The results showed that this reflection had an important influence on the transmitted field intensity of the SIL microscopy system. However,the reflection on the spherical surface of a hemisphere SIL did not change the resolution of the hemisphere SIL microscopy system. The larger mismatch in refractive indiced on both sides of the SIL's spherical interface results in the less transmission intensity of the system. This disadvantage could be overcome by using one layer of antireflecting film that was coated on the SIL's spherical surface or by filling the space between the objective and the SIL with a material with large (but smaller than SIL's) refractive index.

The method of designing binary optical element (BOE) is proposed to realize Achromatic Optical Variable Device (AOVD). The distribution of confined slot was used as target object and then the binary phase structure was calculated by Iterative Fourier Algorithm (IFTA). The structure had directional diffractive character and acted as the cell of AOVD. Two different datum schemes were adopted to design AOVDs of different configurations. AOVD was fabricated by SVG-LDW04 lithography system in patternby-pattern mode and vector writing mode respectively. The minimum width of phase structure of AVOD is 2 μm and the photos of fabricated AVODs were also given. The results show that the directional diffractive binary phase structure was achromatic and apt for hot embossing and offers a new method for AVOD.

A method of laser speckle for information marks measurement of optical disk was proposed.When laser beam illuminating the weak scattering objectted,there was an approximately linear relationship between the speckle average contrast and the roughness of the illuminated surface in the diffraction field.According to this theory,the optical disk can be regarded as a weak diffuse object. In this paper,the patterns generated by several regions of blank,read-in-data and damaged optical disks were studied. The experimental results indicated that this method could be applied to obtain some statistical characteristics of optical disk due to its advantages of quantitative and full-field measurement,which provided a novel technique to character the optical disk quality.

The three-dimensional intensity pulse function of a confocal scanning microscope for secondharmonic wave is derived and compared with that of a two-photon fluorescent confocal scanning microscope. By use of Fourier transformation,the three-dimensional intensity pulse function is theoretically investigated in frequency domain where the transverse and axial cut-off spatial frequencies,together with the transmission bands are given. The results show the optical resolution for second-harmonic wave is better than that for two-photon fluorescence. Such conclusion is also proved from the uncertainty principle.

A more general formula thinking over deconvolution coefficient for computing changes in the signal-to-noise ratio of the spectrum resulting from the Fourier self-deconvolution procedure was derived.Fourier self-deconvolution could reduce the intrinsic halfwidths of lines,which was in practice limited by the noise in the spectrum. The choice of deconvolution coefficient seriously influence the changes in the SNR of Fourier transform spectrum. With the help of the derived formula,the rate of decrease in the SNR as a function of apodization length for six different apodization function was studied,when deconvolution coefficient increased gradually. It was shown that when deconvolution coefficient increased gradually,the rate of decrease in the SNR become great rapidly.

Unfried and fried oils were analyzed and studied by synchronous scan fluorescence spectra and combined with infrared absorption spectra. Synchronous scan fluorescence gave a narrower and simpler spectrum and was of extensive use for multi-fluorescence analysis. In this method,both excitation and emission monochromators were scanned simultaneously keeping a fixed wavelength interval (△λ) between them ( constant △λ mode). In experiment,the optimization △λ was 10 nm. The synchronous scan fluorescence was obtained in the emission wavelength range of 250 nm～700 nm. Compared with fresh oils,in the fluorescence spectra image of fried oils,fluorescence peak value in 370～380 nm disappeared,and two fluorescence peak value in 461 nm and 479 nm emerged. In 1745 cm－1,the intensity of infrared absorption increased. All of this indicate that the number of carbonyl ( C = O) increased,which was the same to chromatogram approximately.

Eu3+ chelates with thenoyltrifluoroacetylacetone(TTFA),Hexafluoroacetylacetone(HFA) and dibenzoyl-methide (DBM) as the ligands and PMMA doped with these chelates were synthesized,respectively. Fluorescence properties of the chelates Eu (TTFA)3,Eu (HFA)3,Eu (DBM)3 in benzene solution and in PMMA matrix were investigated. It was found that the fluorescence intensity of Eu (TTFA)3 was the topmost. The effect factors on the fluorescence intensity of complexes were analyzed. It was testified that TTFA was a good ligand of Eu3+ for red fluorescence emission. Finally,the dependence of Eu (TTFA)3 doping concentrations (0.08 wt.% ～ 0.5wt.%) on the fluorescence intensity and the fluorescence lifetimes were investigated. The results showed that the fluorescence intensity and the lifetimes increased within the doping concentrations investigated. The fluorescence lifetimes were between 280～400 μs. Such fluorescing PMMA might have extensive prospect of applications in optical devices,such as polymer optical fibers,lasers,amplifiers and waveguides.

A novel configuration for millimeter-wave (mm-wave) radio-over-fiber transmission systems with remote local-oscillator (LO) delivery was proposed. The proposed technique provides a very simple solution to base-station access points for pico-cellular networks in order to distribute the future broadband wireless-access services. Both numerical and simulation results show that,622 Mbit/s binaryphase-shift-keying (BPSK) data in the downlink can be successfully transmitted with a bit error rate ≤10－9 over 30 km of a conventional single-mode fiber,for a laser output power of －6.5 dBm,an optical gain of 6 dB,and laser linewidths (LLw's) of 1 MHz,75 MHz,and 150 MHz,respectively.The variance of an additional phase error of the remotely delivered mm-wave LO due to laser phase noise and fiber dispersion is calculated to be only about 30.4 mrad (1.740°),in the case of the relatively large LLW of 150 MHz and a fiber length of 30 km.

Satellite vibration was one of important factors which affected the performance of inter-satellite optical CDMA communication system. Considering the effects of multi-user interference,atmospheric scintillation,avalanche photodiode detector (APD) noise,thermal noise,and satellite vibration,the system model of intersatellite two-dimensional optical CDMA communication system with PPM signal format was presented,and the influence of satellite vibration on the bit error rate of this system was analyzed in detail.The results show that the wavelength,bit rate and satellite vibration could affect the bit error rate of intersatellite two-dimensional optical CDMA communication system all together. In the two-dimensional optical CDMA communication system which bit rate was 622 Mbps and wavelength was 1550 nm,when the standard variance was small (σ≤4 ×10－7),it couldn't affect the bit error rate of this communication system severely. Otherwise,when the normal variance was large (σ≥l. 2×10－6),the bit error rate couldn't satisfy the requirement of communication. Some methods needed to be used to suppress the influences of satellite vibration on the bit error rate of inter-satellite two-dimensional optical CDMA communication system.

The axial strain of D-shaped fiber Bragg grating (D-FBG) and normal fiber Bragg grating induced by bending was analyzed with mechanics of materials. Bending sensitivity characteristic of Bragg wavelength's shift was obtained. Experiment result was in good agreement with the theory analysis. DFBG's bending sensitivity was about 80 times higher than normal circularly symmetrical FBG. The studied D-FBG can be directly applied in bending measurement,and indirectly in pressure or acceleration measurement. The theory analysis and experiment result was helpful for the design of device or sensor system using D-FBG.

A two-layer parallel optical interconnection network has been designed. The top layer was a star network,which was made up of digital routing nod,node computer and optical network interface cards. The maximum transmission rate of single channel was 1.4 Gbit/s and the total throughput of network was more than 10 Gbit/s with eight channels. The bottom layer was a ring comprising optical network interface cards and node computer. The peak transmission rate of optical interface cards was 1.065 Gbit/s. Fiber optic rotary joints that can transmit dynamic data were assembled in sub-layer network between the node computer and sensors. The maximum communication latency inside a ring was less than 5.292 μs. The average communication latency of parallel optical interconnection network was 11.03 μs,and the bandwidth of the ring network was less than 50 Mbit/s.

The influence of different RWA (Routing and Wavelength Assignment) approaches on the optimal performance of p-cycles in WDM networks without wavelength conversion was investigated. The method of load balanced was proposed to achieve nearly uniform distribution of working capacity over the wavelength layers in order to reduce total network capacity. Five RWA approaches were considered,including Dynamic Layered Generalized RWA (DL-GRWA),Shortest Path RWA (SP-RWA),Dynamic Layered with load balanced (DL-LB) Shortest Path with load balanced (SP-LB) and Fixed Wavelength with load balanced (FW-LB). Simulation results show that by means of every approach the total network capacity decreases with the increase of the maximum allowed cycle hops. Among them,SP-LB approach can minimize the total network capacity.

The five series for the Yb3+/Er3+ co-doped Al2O3 films with constant Er3+ concentration have been prepared on the SiO2/Si water by medium frequency magnetron sputtering. The photoluminescence (PL) of the thin films between 1.430 μm and 1.630 μn were investigated under room temperature.Experimental results showed that Ytterbium co-doping efficiently increased the PL peak intensity,and the PL intensity of optimal concentration for 1.OOmol % Er3+ and Yb3+ ∶Er3+ ratio of 10 ∶1 enhance by a factor of about 40,compared with that of 1.OOmol% Er3+ doped film;there existed the optimal Yb3+/Er3+ ratio with constant Er3+ concentration,this mainly was an interacting result of energy transfer and back energy transfer between Yb3+ and Er3+,whereas the optimal Yb3+ /Er3+ ratio decreased with increasing the Er3+ concentration;the change trend of PL peak intensity for only Er3+ oped film was similar with Gauss figure whereas that for Yb3+/Er3+ co-doped film was similar with anti-Gauss figure as a function of Er3+ concentration.

Cu and Ag were implanted into the pores of anodic alumina by means of electroplating. Its transmitted and polarized spectra was measured using UV-3101 spectral photometer,and the relationship of polarization property and incident angle was also studied. The experimental result indicated that such anodic alumina with metallic columns had good polarization property in the near-infrared waveband,and the incident angle had obviously effect on its polarization property.

An optical system of Dome-screen projector which plays important roll in the pilot-training process was proposed. The lens system adopted the Reverse-Telephoto configuration which had an effective focal length of 5.5mm,an F-number of F/4,a field of view of 175°,and a working wavelength in the range of visible spectrum. A discussion about the relationship between the screen radius and the field curve was presented to explain why this system had an advantage in reducing the field curve. A relatively convenient method of choosing the appropriate screen radius was given at the end of the discussion.

A novel blind watermarking algorithm based on virtual channel technique was proposed,by which a gray-scale image was embedded into host image. By modifying coefficients of host image in frequency domain,the host channel can be regarded as a virtual watermark channel,which was composed of several deficient sub-channels. Neither original image nor original watermark was necessary in extraction. Experimental results show that proposed algorithm provides good invisibility and robustness.

An approach of calibration method for three-dimensional (3-D) vision system based on shifted point array encoding was presented in this paper. Initially a 3-D calibration benchmark was established in object space,thus the camera subsystem can be calibrated with the benchmark in light of the concept of benchmark transmission. Furthermore the projection subsystem could be calibrated according to the constraint condition between the camera and the projection subsystems. Once both subsystems have been calibrated,in light of the shifted point-array encoding method the 3-D coordinates of range image could be obtained with moderate accuracy,which could be used to compare with the prescribed benchmark in order to build up a square-error based objective function,leading to a non-linear equation. By solving this equation,all structural parameters involved in 3-D vision system could be determined with appropriate accuracies. Experiment results showed that,after proposed calibration procedure,the 3-D vision system based on point array encoding was able to achieve such accuracy as the standard deviation in X direction is 0.29 mm,0.24 mm in Y direction,and 0.29 mm in Z direction,respectively,for a measuring volume of 300×300 ×80 mm3.

A method for measuring flying object's 3D pose using optical images was introduced. As an important step of the method,the image's processing procedure was researched and explained in detail. The validity of image processing method was tested and verified by applying to a self-made simulative target.The results consistently show that the method has high degree of accuracy and is suitable for practical need.

An image compression project based on the combination of lifting wavelet transform and fractal was proposed. Making the best of the coefficients' distribution,the algorithm was consisted of improved fractal coding in low-frequency of lifting wavelet transform coefficients and SPECK coding in other parts.The experimental results show that the quality of the image was improved at enhancing compression efficiency.

A blind audio watermark embedding algorithm by a holographic technique was proposed. The digital-watermark image to be hidden was phase modulated in a random wise in order to form the object wave. The Fourier transform of the object wave was interfered with the reference wave to form the Fourier-transformed digital hologram. It made full use of the energy compression of DCT (Discrete Cosine Transform) to embed the watermark,in the form of Fourier-transformed digital hologram,into the audio signal by quantification process. The watermark can be extracted without the original audio signal. The process of constructing and reconstructing a digital hologram were described on the basis of the theory of Fourier optics and simulated by the computer. Experimental results show that the algorithm was robust against common signal manipulations and attacks,such as Gaussian noise,low pass filter and cropping especially.

A new designed FED system was introduced in this article and the components of the system were illustrated. The factors that affected the temporal resolution of the system were analyzed in detail,such as the material and thickness of the photocathode,electric field near the cathode,focusing method,deflection sensitivity and sweeping speed. Finally,designed a FED system with 35 nm-thickness Ag film,1 0 kV / mm electric field near the cathode . Magnetic focusing was used and the deflection sensitivity was 26.3 mm/kV,the sweeping speed could reach up to 1.45×108 m/s,so the total temporal resolution was reduced to about 500 fs.

The band-to-band absorption edges of Si/Ge quantum wells were characterized by photocurrent measurement. The regular change of absorption edge was observed in different bias voltage and temperature condition. By fitting of band-to-band absorption edges,the bandgap of Si conduction band to Ge valence band was acquired. With the increase of external electric field,absorption edge curves shifted to low energy direction. By theory calculation,the relationship between the shift of absorption and external electric field was obtained,and it was well agreement with experiment. With the decrease of temperature,absorption edge shifted toward high energy direction. The qualitative analysis of this phenomena was given,and the change rate of bandgap with temperature was acquired by fitting.

On the basis of Helmhots-Kirchohoff diffraction integration,Axial and radial intensity distribution and diffraction pattern of Frenel zone plate for Gaussian laser beam were analyzed theoretically. Numerical results showed that it presented a series of focal points on axis,around each of which there is oscillation of intensity distribution,with the increase of order number of focal point,the intensity increasing rapidly. There were phenomena of focal shifts,and focal shifts increased with the rise of the order number of focal point. The focal depth reduced on inverse square law with the rise of the order number of focal point and increasewith the reduction of zone number or the increase of focal length. On focal planes,the size of light spots was proportional to the width of the most external circle and inversely to the order number of focal point.

The near-field vector electromagnetic distribution in illumination-mode scanning near-field optical microscopes (SNOM) was studied numerically using a two-dimension program based on the boundary element method,taking into consideration of both the sample properties and the polarization of the input light. The numeric results indicated,that in the case of topography-free samples,the power transmission of the optical probe was increased with the increase of the permittivity and the loss angle of the sample material,and that the spot size was hardly effected. However,in the case of topographic samples,the resolution of the SNOM was increased with the increasing of the permittivity and the loss angle of the sample material. Comparison of two operating modes of SNOM indicated that the constantdistance image had a higher resolution for the local change of the sample topography than the constantheight image.