Fiber gratings can be viewed as a periodic high and low refractive index multilayer thin film stack. The total reflection coefficient of this structure is then obtained through a recursion formula, which is derived by using electromagnetic field theory. Bragg matched and detuned uniform gratings as well as non uniform gratings have been analyzed by using this method. The results have been compared with that by using coupled mode theory, Rouard's method and fundamental matrix method, and the accuracy of these methods have been checked.

The effects of the amplifier spontaneous emission noise and the cross phase modulation in WDM on dispersion mamanged soliton (DMS) are theoretically analyzed. Based on the variational method, the mean square frequency shift, timing jitter and bit error ratio of dispersion managed soliton are obtained. For reducing mean square frequency shift of these perturbations, we also fix on the characteristic parameters of compensated fiber and compare three proposed schemes on the performance of DMS, these results can be used to optimal allocated dispersion managed soliton system.

A novel method for designing the interleaver applied in DWDM optical communication is presented. This passive component combines the nonlinear phase feature of the reflective beam within F P cavity and the linear periodic phase characteristic of the beam at certain propagation difference with the frequency. The performance could satisfy the DWDM′s requirement when those two phase matched beams interfered. The theoretic model is simulated using the characteristic matrix of thin film. The result is calculated and analyzed, and the feasibility of this kind of design is demonstrated.

A cascaded M Z fiber interferometer has been analyzed,which is made of several 3 dB couplers in series. Theoretical analysis and numerical simulation indicate that a good comb-like curve will be obtained when the length difference Δ L of interference arms is given by a certain value in order. SSR will increase as adding of the number of interference arms.

Based on the accurate diffraction formula and the accurate expression of light intensity on the transverse plane, the characteristics of axial light intensity of planar wave diffracted by small circular aperture are investigated. Variation relations of the maximum axial light intensity and the numbers of light extremum versus the radius of small circular aperture are given. The application condition of general Fresnel number formula is also studied.

An imported signal to noise ratio (SNR) measuring system for image intensifiers is reconstructed. The signal processing module, computer module and measurement software of the system are redeveloped. The frequency spectrum measurement of noise of image intensifiers is achieved by integrating Fast Fouier Transform (FFT) with hardware filter and digital filter. The improved system is used to analyze frequency spectra of noise of homemade and imported image intensifiers. The results are given and analyzed.

When utilizing laser Doppler effect to measure in plane displacement of an object at long distance, the intensity of Doppler signals of scattering light, SNR and quality of signals are very important parameters, and they affect the distance and accuracy of displacement measurement directly. The Doppler differential method, lock in amplifier and homomorphic filter are studied. A differential optical measuring system with the best effect, a lock in amplifier with high sensibility and high Q and a homomorphic system that can re construct the lost signals are designed. So the transverse displacement measurement of object at distance of 50m is accomplished with the maximal relative error of 1.5%.

The phase measurement method by grating projection is an effective technique in 3 D shape measurement. A novel method-two step phase shifting technique for phase measurement profilometry is proposed. In this method only two phase shifted fringe patterns are necessary in order to extract the phase values, and the phase unwrapping procure is not needed. Hence, this method requires little computing time. The experimental results are given. A comparison, which demonstrates the high accuracy of the new method, is made between the proposed two step and conventional four step phase shifting method.

For the steady question of a self mixing interference system, a mathematics model of the system is deduced based on an effective three mirror cavity model. The boundary of the single solution and multiple ones are given by solving the phase equation of the model. So, the optic feedback level in this system with a stable operating can be determined. This conclusion offers a guide to design the self mixing interference system.

In order to measure the solar irradiance and the earth radiation, a Solar Irradiance Absolute Radiometer (SIAR 1) is constructed. Two important improvements are made on electro calibrated cavity absolute radiometer and the absolute accuracy of SIAR 1 is improved. SIAR 1 has completed the international comparison with WRR in WRC, Switzerland during Sept. 25 to Oct. 13 in 2000, the comparison results showed that SIAR 1 is 0.08% higher than WRR. Whereafter, comparison of STIM with SIAR 1 is made. The average standard deviation among three absolute radiometers of STIM is 0.11%, The second absolute radiometer is accordance with SIAR 1 in the range of 0.09%. So it is concluded that the absolute accuracy of STIM is 0.16%.

A theoretical study on the propagation of single direction light in optical ring is presented. When the angular velocity changes, the frequency of single direction light propagating in optical ring will shift. The analytical expressions are obtained for the resonance conditions when the light propagates in optical ring resonator. A kind of integrated optical waveguide gyroscope structure based on ring resonator and Mach Zehnder interference is designed, which provides a convenient way to sense both the angular velocity and rotational direction. And the precision of such gyroscope is independent of the finesse of optical waveguide ring resonator. Comparing with the optical waveguide ring resonator based on Sagnac effect, this kind of structure has potential to get better performance.

The conventional expression of instantaneous phase of single frequency interferometer is based on inverse trigonometric functions and consequently is not continuous, which is generally not suitable for analyzing or improving the performance of interferometer synthetically. The feasibility of the Neural Network (NN) approach is investigated by simulations and experiment. Both simulating and experimental results show that the novel continuous model based on NN is applicable to practical, noisy signals, and the precision can be very good. Finally potential applications of the new NN approach, especially to the measurement of velocity and acceleration, are introduced.

According to surface plasma resonance effect, the influence of the metal layer thickness on the optic fiber surface plasma wave sensor is studied. Based on the experiment, different thickness of the metal film corresponds to different resonant wavelength when other parameters are fixed and a new kind of distributing optic fiber surface plasma wave sensor is devised. The new sensor will be an efficient tool to detect several parameters at different positions.

The M 2 factors, beam waists and far field divergence angles of the beams of two kinds real refractive index stripe waveguide semiconductor lasers, plane ridge waveguide and plane buried waveguide lasers, are investigated by means of nonparaxial vector moment theory and plane wave spectrum. The waveguide optical modes were obtained by a semi vectorial 2-D waveguide model. The effects of waveguide structure parameters on M 2 facotor are discussed and the beam properties are compared between the two kinds of laser structures.

An inhomogeneously broaden Nd∶CNGG laser end pumped by a CW laser diode was reported. At absorbed pump power of 675.5 mW. The maximum TEM 00 mode output power, slope efficiency and optical to optical conversion efficiency were 105.5 mW21.2% and 15.6%, respectively. It was shown that three wavelengths (1061.3 nm, 1059.1 nm and 1065.6 nm) reached thresholds orderly with increase of pump power, and simultaneous three wave oscillation was obtained eventually.

A cascaded Raman fiber laser (RFL) based on standard mono mode silica fiber and fiber Bragg gratings is fabricated. Pumped by a Yb doped double clad fiber laser, output power of the second Stokes wave around 1176 nm is obtained. The maximal total output power of the RFL is up to 309 mW, and the slope efficiency of the 1176.8 nm output is about 51.5%. Pulses with a repetition rate of 2.9 μs are observed in the laser output when the pump power is near to the threshold. However, when the pump power reaches to a value high enough, stable continue wave output power is achieved.

With computer modeling and experimental test, the gain distribution characteristics in the working medium side pumped by diode bars are studied. The effect of system parameters change on gain distribution is analyzed. The difference of gain distribution charactieristics between diode side pumped and lamp pumped are compared. The Effect on laser beam quality is discussed.

The luminescence of Tm 3+ doped tellurite glass pumped by 793 nm Ti∶Al 2O 3 laser is studied. It is found that there are both strong 785 nm two photon upconversion fluorescence of 1G 4→ 3H 5 transition and weak three photon upconversion 710 nm, 677 nm, fluorescence. The main fluorescence is at 810 nm, which corresponds to 3H 4→ 3H 6 transition. No fluorescence at 1480 nm ( 3H 4→ 3F 4) and 2300 nm ( 3F 4→ 3H 6) were observed.

Zinc tetrasulfo phthalocyanine (ZnPcS 4) was successfully doped into SiO 2 xerogel by sol gel technique and so a homogeneously doped composite was prepared. The changes of ZnPcS 4 UV/Vis absorption spectra during the sol gel process were studied correlated with the amount of dimers and monomers. The results show that the absorption intensity of ZnPcS 4 monomers increases with the time during the early stage of the sol gel process, but decreases in the latter stage. The reasons of such intensity variation are given from the change of the micro environment in which ZnPeS 4 existed during the sol gel process.

Using Crank Nicolson algorithm, the high order harmonic generation from one dimension multi atom molecular ion in an ultra short laser field is calculated. It is found that the resolution of high order harmonics can be seriously affected by initial phase of laser field. A rudimental explanation is given. It can be applied to other theory or experimental study for improving phase matching or producing well defined high-order harmonics by properly adjusting of initial phase of laser field.

Resonantly enhanced nonlinear refraction in rare earth doped solids is studied with femtosecond degenerate pump probe two beam coupling spectroscopy. An ultrafast resonant nonlinear refractive index of the order of 1×10 -14 cm 2/W is measured in Nd∶glass, and it is 10 2 times greater than the host material. It shows that both the transient probe transmission and the nonlinear refraction can be effectively controlled via the coherent coupling of probe beam with the pump through Nd∶glass sample. The experimental observation of the femtosecond resonant nonlinear refraction response in the rare earth solids may implicate important applications in ultrafast optical switching. It shows that coherent control can be applied to improve the modulation depth of ultrafast optical switching. Resonant nonlinear refraction measurements in other rare earth doped materials such as Er∶YAG and Nd∶YVO 4 demonstrate the general applicability of the pump-probe technique.

A comprehensive analytical approach towards cascaded second-order nonlinearities was presented. The nonlinear phase shifts by cascading in type Ⅱ second harmonic generation were investigated anlytically. The results show that type Ⅱ second harmonic generation can lead to large intensity dependent phase shifts for the input beams under a variety of conditions, provided that the orthogonal input components have unequal amplitudes. The analytical results can be used to optimize the process of cascaded second-order nonlinearties to obtain a certain phase shift with minimum power requirements. The effect of intensity dependent polarization rotation induced by the nonlinear phase shifts and a kind of all-optical polarization switching based on this effect were analyzed and discussed. These results are quite appealing for developing a new all-solid passive mode-locking femto-second laser device based on the polarization switching.

By using Nd∶YAG mode locked pulse laser (λ=532 nm, τ 0=35 ps), the third order nonlinear optical susceptibility χ (3) , and time response properties of liquid crystals containing Schiff base and Naphthalimide are measured with forward degenerate four wave mixing (DFWM). The corresponding nonlinear refractive index coefficient n 2, second hyperpolarizability γ (3) are calculated. The mechanism for their nonlinear effect is discussed.

The factors affecting the contrast performance of liquid crystal light volve (LCLV) projection system are quantitatively analyzed. A three dimensional mathematic model is built to trace the rays. The effects of wave plates and optical thin films are analyzed based on the theory of Jones matrix and vector optics. The theoretic calculation results of systems with or without wave plates are presented. From these data, it is concluded that wave plates with proper phase changes can greatly improve system contrast.

The designing considerations and procedure of hybrid refractive diffractive ultra wide angle (70°) eyepieces are presented, one is with two diffractive surfaces and another is with single diffractive surface. The factors such as the balance between aberrations, the manufacture issue of the minimum feature size of the diffractive element and the diffraction efficiency were taken into account in the design. It was shown that the performance merits, such as transverse aberration, lateral color, are greatly improved compared with the conventional Scidmore eyepiece, while the hybrid systems offer considerable reduction in the apparent size, weight and number of elements. Finally, the parameters of the diffractive surfaces were presented.

On the basis of research of the ordinary double pass polarization interference filter with identical thickness retarders, the new type double pass polarization interference filter is deduced in theory. The spectral and angle characteristics of three types of polarization interference filters are analyzed. The result shows that the new type double pass polarization interference filter has better spectral characteristics in practice can reduce the number of retarders, and is expected to be used extensively in color separation and recombination system of liquid crystal on silicon projector.

Diffractive properties of two dimensional relief gratings made with electromagnetic anisotropic medium are theoretically analysed by using rigorous modal theory, and the degradation is discussed. Reflection transmission coefficient matrix (RTCM) algorithm and correct Fourier factorization rules are adopted to improve stability, convergence and calculation efficiency of numerical computation. Numerical compution on gratings shows that the method is satisfying in credibility, stability and convergence.

TiN films were prepared with different process parameters by magnetron sputtering apparatus. The optical properties and optical constants were investigated in detail. The depth compositional profile and surface morphology were studied by Auger electron spectroscope and atomic force microscope. The results indicated that the optical properties strongly depend on chemical proportion of titanium and nitride in TiN film. It is confirmed that the stoichiometric TiN films have good spectral solar selectivity. Furthermore, sputtering process using the substrate applied with negative bias voltage can improve the properties of TiN films.