Based on couple-modes equations, the reflection spectrum of sinusoidal-Tapered fiber grating was calculated in detail. It has been found that, under different sinusoidal-taper profile, the single peak of periodic grating splits into two or three peaks, This kind of grating is something like a comb-filter, and has good usage in WDM optical fiber communication system, multi-wavelength tunable optical fiber laser etc.

A new method of 360° turning 3D shape measurement is presented in which light sectioning and phase shifting techniques are both used. A sine light field is applied in the projected light stripe, meanwhile phase shifting technique is used to calculate phase of the light slit. The wrapped phase distribution of the slit is formed and the unwrapping process will be made by means of the height information based on the light sectioning method. So phase measuring results with better precision can be obtained. The target 3D shape data can be produced according to geometric relationship between phase and the object heights. The principles of this method are discussed in detail and experimental results are shown.

Rotation invariant target detection using a modified amplitude modulated hybrid optical circular harmonic joint transform correlator is proposed. In this technique, the reference images (i.e. the real and imaginary parts of the circular harmonic component), the disk-like local bias function and the target image are displayed simultaneously in the input plane. The joint power spectrum is firstly modified by the subtraction of the power spectra of the input-scene-only (with local bias function) as well as of the reference image (with local bias function) and by the addition of the power spectrum of the local bias function from it. Then the resultant modified joint power spectrum is multiplied by the amplitude modulated filter function. The technique is found to yield a better correlation output than a classical circular harmonic joint transform correlator does. Computer simulation results and hybrid optical experimental results are given.

By using the constrains on the object plane and on the hologam plane, we have realized the phase retrieval reconstruction of in-line hologram. It has proved to be effective by computer simulation. A new design for real time reconstruction of soft X-ray in-line hologram has been proposed.

The principle with the experimental configuration to measure both the magneto-optical Kerr and Faraday effects are given. The system is simple and is fully controlled by computer. Using the Forier transfer analysis method, the spectra of the absolute Kerr and Faraday parameters can be measured in the precision data range from 0.01° to a few hundred degrees and in the photon energy range from 1.5 to 6.0 eV. Taking for examples, the measured spectra of Kerr and Faraday effects for MnBiAl alloy thin film sample and GaP bulk sample were given. Since the Faraday rotation angle is proportional to the thickness of the sample, the data should be carefully analyzed in the situation in which the fundamental absorption edge of the magnetic sample is only determined by the Faraday spectra.

The principle and method of measuring X-ray focus spot are presented. Combination-type diagnostic technique is used to obtain the three-dimensional information about X-ray radiation spot varying with time, space and energy spectra. The relations of radiation spots with time and incident laser energy are obtained. The effects of expanding plasma, detection threshold, measurement energy region as well as the measurement position on the X-ray focus spot measurement are observed.

Optical coherence tomography (OCT) using low-coherence light as the source is an new technique in the field of imaging. By the method of Monte Carlo simulation, the coherent signal under different scattering conditions, the difference between single scattering and multiply scattering and its influence on imaging are discussed. Farther, we outline a method to utilize the difference to enhance the image sharpness and signal intensity. The influence of the incident beam diameter on the imaging resolution is dynamically studied to get a helpful conclusion to the experiment.

Physics property of target and background is described by scarttering from rough surface. According to Kirchhoff approximation, backscattering enhancement of one dimension random surface is observed using Monte-Carlo simulations. Gauss rough surface and fraction rough surface are studied. Rough surface of the same statistical characteristic at different wavelet scale is discussed. The results are in accord well with experimental fact.

A novel wavelength scanning fiber-optic interferometer for absolute distance measurement has been proposed. The output signals from two interferometers are analyzed in time and frequency domains. The influence of multi-beam interferences, and the relation between the signal to noise ratio and the random drifts of the scanning wavelength are deduced. From those deductions, some demands upon the design and production of the tunable external-cavity semiconductor laser are posed. Based on the conclusions in this paper and the digital signal processing techniques, an effective algorithm is established. So that the precision of 0.05 μm and resolution of 0.01 μm can be satisfied.

Spontaneous emission factor β is an important parameter to characterize semiconductor optic-electronic devices. In characteristic analysis of the superluminescent diodes, especially, in calculation of optical intensity using the rate equations, the value of the factor β estimated in the laser diodes is commonly applied since the superluminescent and laser diodes are similar in the structures. However the two types of devices are quite different, the extended usage of the factor may lead to confusion in physical concepts and make great error. In this paper, the spontaneous emission factor β for the superluminescent diodes is discussed, and a new concept on average value of the laser β is proposed. From estimation and comparison, the factors β of gain-guide and index-guide structures are obtained.

By using the nonlinear Schrodinger equation, an analytical treatment for the propagation of the astigmatic beam in a Kerr media is presented. The propagation in a Kerr medium can be calculated by a differential equation of the first order. The formulas are applied to calculate the self-consistent Gaussian mode of an astigmatic resonator used in a Kerr lens mode-locked laser.

A new-type weak feedback from a blazing grating in Littrow configuration was used to force a single-mode GaAlAs semiconductor laser to run at 852.11 nm. The frequency tuning range of 2.2 GHz around 852.11 nm and the output power higher than 90% of total power in the case of free running were obtained.

The relaxation between laser levels can strongly affect the operation and efficiency of high power laser amplifier. The influence of the thermalization rates among the components of the two multiplets to which the laser level belong and depletion rate of terminal laser level is studied in detail. A group of modified laser rate equations in consideration of the influence of thermalization and depletion between laser levels is are obtained. The properties of a practical amplifier is presented by numerical simulation.

Tm3+ and Yb3+ co-doped ZBLAN glass emits strong blue lights when pumped by a 798 nm laser diode which excites Tm3+ ions to 3F4 level. The energy transfer processes between Yb3+ and Tm3+ ions both forward and backward prove to be the origin of upconverted emissions. A brief discussion on this upconversion pump scheme is presented.

The transmittance spectra and Fluorescence spectra of Eu3+:Y2SiO5 crystal have been studied at room temperature. Spectral analysis shows that two optical sites with low symmetry were occupied by Eu3+ in this crystal. Spectra of two kinds of C1 sites were resolved at 5D0 level by transmittance spectrum and fluorescence spectrum. There is 0.18 nm space between them, and the spectral linewidths of each site are about 0.1 nm. In addition, some of the level structure of 7FJ(J=0, 1, 2, 3, 4), 5D1, 2 and 5L6 were also observed.

Porous silicon was employed as absorbing medium because of its large surface areas. When 2.2′ cyanine monomer molecules and its J aggregated molecules or fluorescein-sodium were absorbed to porous silicon, their fluorescence were enhanced greatly. The energy transfer effects were observed between porous silicon and dye molecule. The fluorescence enhanced mechanism and energy transferring effect were discussed and analyzed in detail.

Wavelength Division Multiplexed (WDM) system characteristics using various dispersion compensation schemes are compared by computer simulation. In our model, eight 10 Gb/s WDM channels with channel spacing of 100 GHz are transmitted through cascaded optical amplifiers. Fiber dispersion, self-phase modulation (SPM), cross-phase modulation (XPM) and four-wave-mixing (FWM) effects are considered. Dispersion compensation schemes include: conventional single mode fiber (SMF)+dispersion compensating fiber with positive dispersion slope (DCF1), SMF+dispersion compensating fiber with negative dispersion slope (DCF2), non-zero dispersion fiber with positive dispersion (TW1)+non-zero dispersion fiber with nagetive dispersion (TW2) and TW2+TW1. It is shown that TW2+TW1 has the best performance, where SPM, XPM and FWM are roughly equal. On the other hand, SMF+DCF1 results in the worst performance, where the combination of dispersion and SPM effect dominates, and the shorter wavelength channels suffer from severe pulse distortion.

Propagation of the unbounded bright spatial soliton in non-Kerr type media is studied. Numerical calculation results show that propagation of the unbounded bright spatial soliton can take place in the so-called cubic-quintic nonlinear medium. The stability of propagation depends on the values of the asymptotic wave number of the background plane wave q, and of χ(3), χ(5), where the nontrivial phase variation also plays an important role.

If new atomic coherence is introduced into correlated-emission laser systems, such systems can produce bright two-mode sub-Poissonian light. Using Scully-Lamb theory the Mandel Q parameter is calculated. When quantum noises of relative amplitude and relative phase drop to vaccum noise levels, average mode exhibits sub-Poissonian photon distribution; when quantum noises of average amplitude and average phase drop to vaccum noise levels, relative mode exhibits sub-Poissonian photon distribution; the optimum Mandel Q parameter is -0.5. In the above two cases, each of two CEL modes exhibits sub-Poissonian photon distribution with optimum Mandel Q parameter of -0.25.

In a general way, even q-coherent states in a finite-dimensional Hilbert space (FDHS) case are constructed explicitly. Some quantum statistical properties are discussed. It is found that squeezing and antibunching properties of even q-coherent states in a FDHS case are different from those of usual even q-coherent states. No matter the q-deformation exhibits or not, the former all exhibits not only quadrature squeezing but also antibunching effect.

Based on the interference between two-photon and two-photon processes, we have studied the ultrafast modulation spectroscopy(UMS) in a four-level system. The possibility of using UMS in a four-level system to measure the energy difference with Doppler-free precision has been demonstrated.

Employing computer to control optical scanners and lock-in amplifier to modulate gain and shift phase, a fluorescence phase-sensitive imaging system has been investigated for ruby and Ti-sapphire experimentally. The images with phase shift of π/12, π/4, and 7π/12 were obtained. The time resolution and the space resolution, as well as the practicality, of the system are analyzed.

The refractive index, absorption index and absorption spectra on a cobalt phthalocyanine (CoPc) thin film are theoretically calculated. The theoretical resultis is in a good accordance with the measured data. The theoretical formulas about optical absorption and dispersion changing with frequency in dielectric are analized.

A large size self-sustained film with considerable thickness ranging from 30 μm to 500 μm was prepared through sol-gel method by adopting dimethyldiethoxysilane/tetraethoxysilane composite material as precursors. The film exhibits satisfactory plasticity and film forming capability as well. AFM (Atomic Force Microscope) investigation of the film surface showes a mean roughness of 0.3 nm. Gas chromatogram/mass spectrum analysis indicates that a large amount of ［(CH3)2Si-O］n molecules were formed during the hydrolysis and condensation processes. These molecules act as space filler within the gel network. Such filler not only leads to the structural flexibility and plasticity of the film, but also inducess the substantial decrease of the capillary forces and shrinkage in the film.

The optical properties of NH3-treatment SnO2 films, prepared by sol-gel technique are investigated. It is found that the films have a good antireflective performance, and also have good electrical and mechanical performance.

Thin films of TNPPcZn (Tetra-neopentoxy phthalocyanine Zinc) were spin-coated onto glass substrates. Studies on the changes of TNPPcZn aggregate have been made by using films annealed at various temperature. The XRD patterns and absorption spectra over the wavelength range of 500～800 nm were measured. With the increasing temperature, monomer of TNPPcZn was transformed into aggregate gradually. But when the temperature was upto 450℃, aggregate was changed to monomer again. At the same time, phase changes occurred from amorphous to crystal then to amorphous again.

The preparation precedures of the WO3 electrochromic thin film and the semi-solid state WO3/LiClO4+PC/TiO2 electrochromic device are studied. The cyclic voltammogram characterization of WO3 thin film and electrochromic device (ECD) with different scan potentials and scanning rates are investigated. The coloration efficiency of WO3 film in 1 M/L LiClO4+PC is obtained. The results show that the sol-gel process is an effective method to prepare the large-area electrochromic smart windows.