The wavelengths of iodine laser are in an atmospheric micro-window. The absorption by water vapor is its main absorption besides aerosol in this region. The absorption coefficients and transmittance of several model atmospheres are calculated. In China, from south to north, from summer to winter, the water vapor density is decreasing, and the iodine laser beam absorption rate by water vapor is decreasing as well. It is better that an iodine laser beam transmits vertically upwards than horizontal flatly on the sea level. The absorption of an iodine laser beam with single main line is less than that with multi-lines.

The effects of birefringence on performances of SOA-based interferometer devices are analyzed theoretically. The necessity of fabricating SOA whose gain and induced phase shift are both independent on polarization state is proposed. The calculations for a SOA-based Mach-Zehnder interferometer wavelength-converter indicate that the extinction ratio will decrease and become very sensitive to the polarization state of input light if there is birefringence in SOAs, the extinction ratio variation is higher than 10 dB. A scheme is proposed to eliminate these effects, and the possibility of making a SOA with both gain and induced phase shift insensitive to polarization is analyzed.

The radiation-frequency filters employing optical fiber lattice networks are investigated. The response functions of the fundamental elements are discussed. The optimum configuration conditions and parameter ranges of these lattices are deduced to achieve the optimum operation. A compensation method to realize a optimum notch filter is developed and implemented by matching the loss of fiber delay line with the coupling-coefficient of couplers. Experimental result shows that this method is effective, convenient, and well accorded with theory.

A simple configure for automatic gain control of optical amplifiers is presented, in which two pairs of FBGs are used to form dual-oscillating lasers. The experimental results suggest that the configure can be employed to significantly reduce surviving channel steady-state and transient power excursion. Moreover, the effects of the gain control EDFA on surviving channel at different add/drop frequency are discussed. Experimental results show that the dual-oscillating laser gain controlled EDFA operates satisfactory with channel′s add/drop frequency up to 43 kHz which is significantly higher than that with single-oscillating laser control.

The contact poling is employed to study polymer-based electrooptic (EO) modulators. The contact poling method and technology are investigated for the designed device structure. EO phase and polarization modulators are fabricated by using contact poling. Working at 1550 nm, a phase or polarization modulator is demonstrated with a half-voltage of 45 V and the electrooptical coefficient of 11 pm/V by measuring polarization modulation of the poled devices.

A searching method of Fourier series contrast capable of producing flat spectral transmittance for birefringent filter is presented based on the interference of polarized light. All the possible numerical solutions of the deflection angles of the crystals can be searched out in a relative large range of passband and stopband when the ripple is relatively small. For the system containing three birefringent crystals, all the possible deflection angles of the crystals were searched out when the ripple is not greater than 0.1%. The influence of the deflection angles and thickness of the crystals on the system′s spectral transmittance was discussed.

The experimental results that a single element based on the Talbot self-imaging effect realizing both beam splitting and wavelength-division multiplexing functions are presented. For the input beam with two wavelengths, and by designing the parameters such as grating period and the fractional Talbot distance, the interleaved self-images in space of a grating corresponding to two wavelengths can be exactly observed in the experiment.

The principle on refractive index of core and reflectivity of FBG changing with temperature and time was analyzed. With some research work on appropriate model, the concept of accelerating decay is raised, upon which a novel annealing process is established. With the data measured, the future characteristic of grating can be given under certain temperature and time. The theoretical and practical results are almost in agreement.

Three kinds of add-drop multiplexers (OADMs) based on fiber gratings and circulators are proposed and demonstrated. There is significant homodyne crosstalk reduction of about 24.4 dB, 39.3 dB and 23.6 dB, 24.6 dB on the dropped and added channels, respectively, for the best proposed Ⅱ-type structure and Ⅲ-type structure as compared with the conventional Ⅰ-type structure.

In the experiment of two-wave mixing, the photovoltaic effect on photorefractive property was studied in some doped LiNbO 3 crystals. Strong lognitudinal photovoltaic effect can be got in Ce: Fe: LiNbO 3, which can modulate the diffraction efficiency at the rate of 59.7%; grating of polarization records was also made in Ce: LiNbO 3 and Zn: LiNbO 3 crystal, due to the transverse photovoltaic effect.

A new method for disk-type photopolymer high-density holographic storage based on angular-multiplexing and spatial-multiplexing is described. The effects of optical setup on the recording capacity and density are studied. The recording optical setup for getting the maximum recording capacity and density is optimized.

In the canse of engineering slope with confocal microscopy, the paraxial condition is not suitable. The conclusion derived from Fresnel approximation condition is not suitable for this situation. The axial response of confocal microscopy of slope measurement is first acquired with the application of Kirchhoff diffraction formula, and the axial response of confocal microscopy derived from Fresnel approximation condition is just a special case of the general module given in this paper. Meanwhile, as the detectors are arranged in a differential way, the theoretical module of measuring signal is obtained and analyzed. Some slopes with different angles are measured and a series of experimental curves are presented. With numerical calculation, the conclusion that experimental result accords with the theoretical analysis is inferred. The slope of 10° angle block gauge is profiled with resolution of 20 nanometer with the differential confocal microscopic system.

A fiber-optic evanescent wave biosensor has been developed based on the principle of evanescent wave while light propagates in optical fiber. Sensitivity limit of 0.01 nmol/l is obtained from the detection of Cy5 serial solutions with various concentrations. And an ideal result of signal-to-noise ratio of 4.61 is obtained when the biosensor is used to measure Legionella pneumophila solution of 0.01 μmol/l. All the results are comparable with that obtained by a commercial biochip scanner.

laser diode (LD) end-pumped Cr 4+: Nd 3+: YAG co-doped microchip laser with 1.1 mm-cavity length is developed, which can achieve very stable output pulse sequences with 6 ns-width, almost 18 mW average power and 1～10 kHz repetition rate. Theoretical analysis is given out and an expression for pump threshold-power is derived. The calculated results are in a good accordance with experimental data

Picosecond gain and refractive index nonlinearities in semiconductor optical amplifiers (SOAs) are simulated for repeated pulse injection case in which the repeatition period is shorter than SOA carrier lifetime. The simulation is implemented by using a multi-section model and starting from the rate equation. The aberration of the temporal profile of the output pulse, gain and phase change induced by pulse injection, and frequency chirp on the output pulse are given for each injected pulse. Gain and phase change induced by return-to-zero (RZ) optical signal stream is also given.

The influence of thermal lens on the width of dynamic stabilization, angle of divergence and output mode of solid-state laser with asymmetry flat-flat cavity was analyzed by using transition circles theory. Compared with the ABCD matrix method which need a large number of computations, this method was relatively simple and the result was easily understood. Moreover a simple method to measure the length of thermal focus is given developed from this theory. By properly designing the parameters of resonant cavity, steady 10 W quasi-TM 00 mode CW output was achieved when the pumped power was 21 W. The mode and length of thermal focus of laser were measured. The experimental result was in accordance with theory.

An all-solid-state Q- switched external frequency-doubled Nd: YAG laser is developed, which generates green laser output greater than 20 W with a type-Ⅱ phase-matched KTP crystal. Beam quality factor of the laser M 2 is about 4, and peak power is higher than 1.15×10 5 W.

A novel actively mode-locked fiber laser for generating dual-wavelength picosecond pulses was proposed by using an F-P LD as the modulator in the ring cavity. A linear chirped fiber grating (LCFG) was used as wavelength selector and to produce temporal-spectral multiplexing of the pulses in the gain medium to reduce cross-saturation effects. Stable dual-wavelength pulses with a wavelength spacing of 0.92 nm at the room temperature were experimentally demonstrated and the wavelengths could be tuned in a range of about 3 nm.

A 4.9 W CW ytterbium-doped fiber laser operating in the 1110 nm region and near diffraction-limited was reported. For a silica-based double-cladding fiber with rectangular inner cladding, slop efficiency of 43.6% was observed for pumping by a diode-laser operating near 910 nm.

The photo-induced anisotropy property of a new kind azobezene side-chain polymer [4(4′-phenylazo)-poly(glycidylmethacrylate),DAP-PGMA] is measured with pump-probe technique. A larger photo-induced birefringence of Δn 6.60×10 -4 and a much shorter rise time of 40 ps than those of P (MMA-CO-MAZ) are obtained in DAP-PGMA. The picosecond process is attributed to the trans-cis isomerization.

The Judd-Ofelt parameters, oscillator strengths, radiative transition probability, radiative lifetime,quantum efficiency and upconversion coefficient of the Er 3+, Yb 3+ co-doped aluminosilicate glasses were calculated by the Judd-Ofelt theory, fluorescent lifetime and absorption spectra. The effect of Yb 3+ and Er 3+ ion concentrations, OH -groups on the spectroscopic and upconversion fluorescence properties was studied in this Er 3+, Yb 3+ co-doped aluminosilicate glass. It is found that at 1.56×10 20 cm -3 Yb3+ and Er3+ ion concentrations, the glass has the best spectroscopic properties.

A math model of cube corner retroreflector (CCR) with dihedral angles errors is built with matrix optics and vector operating methods. A numerical simulation method for studying the characters of beam reflected by CCR is presented. The characters of intensity distribution of the beam reflected by CCR at several propagation distance is simulated with numeric method. The propagation property and characters of energy profile in near field or far-field are studied. According to the condition of velocity aberration compensation, the design of the CCR for satellite aboard is discussed.

The invention of a novel holographic polymer dispersed liquid crystal volume grating is reported. The H-PDLC volume grating has very high diffraction efficiency, and it has the electrically switchable character with short response time. H-PDLC grating is a relatively new class of optical devices that hold high promise for many applications ranging from switchable windows, optical communication device to projection displays.

Supercontinuum light with a spectrum covering visible range was generated in a photonic crystal fiber launched by the 25 fs laser pulse train from a Ti: sapphire laser oscillator at 800 nm wavelength. The fiber has a core diameter of ～1.8 μm and a length of 10 mm. By setting the laser energy at 2.5 nJ, it corresponds a peak power of about 0.1 MW, respectively, coupling efficiency of 17% was demonstrated.

The measurement of optical absorption spectrum of a novel organic material Zn-tetrabenzoporphin-crotonic acid-phenoxy resin (Zntbp-CA-PhR) is reported. The nonlinear absorptive characteristic of the sample illuminated by lasers was studied. And the absorption alternation and kinetic process of the major spectrum bands were observed. The saturable absorption (SA) and reverse saturable absorption (RSA) appeared as the input fluence increases and re-reverse resaturable absorption process of the material was demonstrated in the experiment. These properties occur in a broad range of visible spectrum. The physical mechanism during the whole course is qualitatively analysed. The present work offers an evidence both in theory and experiment for organic material applying in frequency domain optical information storage and optical limiting.

Titanic thin films have been prepared on K9 substrates by ion beam sputtering method. The surface morphology is studied by using atomic force microscopy (AFM). The images show that surface is isotropic and self-affine. The surface can be quantitatively described by the roughness exponent α, the lateral correlation length ξ, and the interface width w. The value α of the Ti film is measured to be 0.72, which gives the related local surface fractal dimension D s2.28. From these values, it is suggested that the growth of Ti film is more consistent with a conservative growth process and can be described by using a noisy Kuramoto-Sivashinsky equation.

The imaging principle of X-ray fluorescent tomography and its application in microanalysis field are introduced simply . Not only fluorescence but also various scattered light are produced while high energy X rays interact with substance. In order to eliminate the influence of these scattered light to imaging result, a method is proposed in which a doubly focusing crystal monochromator is placed normal to the accident X rays to separate X-ray fluorescence from the background and focuse it to a point on the detector surface. The method not only enhances the intensity of X-ray fluorescence but also permits the use of a smaller detector.

Phase imaging with partially coherent X-ray is analyzed in terms of the optical transfer function (OTF). Differential phase-contrast imaging and direct phase-contrast imaging are discussed, and the proper experiment parameters with good image contrast and resolution are obtained. The phase restoration using image processing method, such as image fusion is discussed. The process of phase imaging and phase restoration is simulated, and different methods of phase restoration are compared.