In this paper, the nonlinear optical effect of a sandwichlike optical switch composed of nonlinear media with negative refractive index variation and light irradiation is discussed. Starting from its fundamental theorem, we analyzed the mechanism of light-induced refractive index variation and inferred that the light-induced thermal effect is the major cause of the refractive index variation. Then, we discussed in detail the factors which influence the time response characteristics. The theoretical analysis agrees with the experimental results.

This paper presents the research on the interferometric fiber-optic sensor's PGC scheme which is suitable for the construction of the acoustic sensor array. The new bandwidth requirement of the scheme is analyzed, and high sensitivity fiber-optic acoustic sensor detected by PGC scheme is successfully developed with LD and its frequency modulating technique. The stabilized acoustic signal is obtained by the sensor in the state's first class acoustic measurement station.

In this paper, an analytic formula is given to show the relationship between the diffractive efficiency and fabrication error of 4- step binary optic elements by using the scalar diffractive theory. The formula has been disscussed in some situations and compared with the results of simulation complished by us before. The results of the two methods agree well. The finding may play a role in guiding the fabrication of binary optic elements.

A thermally compensated frequency stabilization system is nonlinear with large time delay. Its control process is too complex to describe with the traditional model. As a result, the conventional PID algorithm designed by experiment has the disadvantages of difficulty in adjustment and control performance. This paper presents a new algorithm; model predict control (MPC) algorithm, which uses the Hammerstein model for forecasting the process output over a certain horizon in the future, optimizing the control in long-range predictive control strategy. The concept is implemented in a real industry scale single-chip-processor controlled thermally compensated frequency stabilization system. The result indicates that the algorithm is evvective. The laser tube reached a frequency stability of 6.7×10-9 in the sampling period of 10 s.

The experimental study of embedding optical fibers into smart composite materials is presented in this paper. This technology includes the stacking method of composite lamination, the technique of embedding optical fibers, the protection of embedded optical fibers in heating and pressurizing processes, the lead-out method of embedded fibers and the protection of the fibers in the edges of composites structure when the optical fibers are led out from the host materials.

This paper studied the lateral displacement-measurement technique by using the laser Doppler effect of the moving grating which acted as a scatterer. The measurement principle was described by analyzing the optical system in which the grating was chosen to produce beat frequency while the polarization was used to obtain phase-shift. The direction identification principle using polarization phase-shift was also analyzed.

Graphite was ablated by a 400 us free-runing Nd:YAG laser and the reactivity photoacoustic spectra of ablation were detected . The acoustic spectra of ablation have a special double peak structure which does not depend on the length of the photoacoustic cell. The heavier the ablation is, the faster attenuation the ablating acoustic spectrum has. The rising time of the sound crest of ablation is about 400 us. With a 1. 10 mm diameter light spot on the surface of graphite, if the laser energy decreases from 3 ms to 8 ms, and the critical ablating energy of graphite is about 65 mJ. The peak value of the sound crest of ablation is directly proportional to laser energy. According to the analysis of the ablated spots by EMS, vaporization of graphite leads to double peaks in the acoustic spectrum and the corrugated surface on the inside surface of the ablated hole.

The electron transfer process in photostimulated luminescence is studied and a set of equations are set up. The linear relationship between readout and write-in signals in X-ray image storage materials is obtained theoretically by solving these equations. This result is confirmed in the experiments of BaFCl:Eu2+.

The interband crosstalk in the WDM system will degrade the system BER by penalizing the extinction ratio in each channel. But in multi- wavelength optical cross-connect networks, there is another kind of crosstalk, intraband crosstalk, in addition to the interband crosstalk. The intraband crosstalk will result in beat-noise which can be detected by the receiver and has more severe impact on the system BER than interband crosstalk. In this paper, we analyze two kinds of crosstalks, and show that our calculat result coincide with the results from experiment very well.

An experimental airborne laser bathymeter has been developed and a filed trial has been conducted. The Q-switched and frequency-doubled Nd:YAG laser output is of 100 Hz pulse repetition rate, 2 MW peak power, and 8 ns pulse width. The green light receiving telescope is transmissive with a 1400 mm focal length and 200 mm aperture. The varying-gain control of the PMT and logarithmic amplifier are used to compress the 105 dynamic range of received signals. The system was installed in a helicopter. The experimental results are described in the paper.

In this paper, Ca modified ( Pb, La )TiOs films were deposited on Pt coated silicon substrates using an ArF excimer laser. The films are polycrystalline and exhibit good ferroelectric and pyroelectric properties at room temperature. Because of the Ca modification, the figures of merit of the films for both specific detectivity and voltage responsivity are almost comparable with those of c- axis oriented PbTiO3 or (Pb, La) TiO3 films on the MgO single crystal substrate. Since these good results are obtained from the films on silicon, it is therefore of significance for monolithic integrated infrared image sensors.

Because of the high reflectivity and the high thermal conductivity, aluminum alloys are considered as the forbidden zone of CO2 laser welding. Without any fillers and under ordinary surface conditions, several aluminum alloys (3004 and 6063 aluminum alloys) are welded successfully through using appropriate laser welding parameters, and the metallographic structure of 6063 is analyzed.

A high-frequency and high-power InGaAsP/InP laser structure was establishedon the basis of buried crescent lasers by using the proton bombardment technique-theselected proton bombarded the buried crescent laser (SPB-BC). At room temperature, the maximum CW output power of 80 mW and a 3 dB modulation bandwidth of 6 GHz were obtained for a laser with a cavity 500 (am long on a p-type InP substrate.

In laser materials processing, the transverse beam intensity distribution affects processing quality greatly. In this paper the phase shift (also called accessary phase overtaking) in laser beam is used to analyse the high power CO2 laser beam transverse size and intensity distribution. The transverse beam size and intensity distribution in different positions in a TLF6000 laser beam propagation were measure by UFF100. The theory is agreed with measurement. According to this theory, an optical transformation system is designed to attain the minimum laser beam intensity distribution near the laser beam focus.

Electrical wavelength switching of an actively mode-locked, fiber Bragg grating incorporated fiber ring laser is demonstrated. Output optical pulses from the laser can switch between two wavelengths determined by the Bragg wavelengths of two fiber gratings in the ring at the rate of 105 per second.

A single stage magnetic pulse compression (MFC) system for High-power copper vapor laser was developed. Basing on the physical characteristic of the magnetic material, several problems noticeable are presented, including how to choose magnetic materials, and how to define the geometric dimensions of the system and the ability to resist DC high voltage.

The generation of single-mode sub-Poissonian light by lasers is studied. A general master equation is presented, which can be applied to any stationary atomic injection and allows for systems of finite cavity lifetime. The Mandel factor for the output photon number is derived. It is pointed out that on the basis of pump-noise-suppression, the fluctuation of the output photon number can be reduced further by shortening the cavity lifetime as well as suppressing the spontaneous emission.pump-noise, cavity lifetime as well as suppressing the spontaneous emission.

From the theory of quasi- phase- matched second harmonic generation, a theoretical analysis on errors, which departure from ideal quasi phase matched LN waveguides with ferroelectric domain inversion gratings, is given. The errors in the domain inversion grating are analyzed, and their effects on the output power of the second harmonic generated are found.

In this paper, we present a modified split-step Fourier method, which is used to study the dynamic behavior of optical soliton in the optical fibre with arbitrary perturbation of the dielectric constant. This paper focuses on the perturbation which takes the sine form. The effect of amplitude, frequency, wave number, and initial phase difference on the propagation of optical soliton is investigated.

The analytical expression for the diffraction distribution on the axis of a Gaussian beam through a circular phase- plate is obtained. It is found that the intensity of the diffracted light is larger than that of the free Gaussian beam in a wide range, but the intensity in the infinite far field is less than that of the free Gaussian beam.