Silicon substrates have optical and mechanical properties that provide excellent opportunities for fiber optic sensors. The microbeam forms a structure that functions as an optomechanical modulator. Modulated light can be use to excite the microbeam into resonance. The measured value (such as pressure) causes the deformation of the substrate and, consequently, varies the resonance frequency of the fundamental flexural mode through the intrinsic tension in the microbeam. When the beam vibrates, the incident light is modulated and the reflected light is used to sense vibration of the beam. Microbeams attached to the substrate at both ends are highly strain sensitive and form the basis of a variety of sensors, including pressure sensors, accelerometers, strain, vibration, and temperature sensors. In this paper, the problems in measuring the vibration of microbeams are analyzed. A modulated light from a laser diode has been used to excite the microbeam into vibration. The vibration of the microbeam is measured by using a laser interferometric method. The test results suggest that this method can be used for precision measurement of microbeams.

Effects of the fusion temperature on optical properties of biconical fibers are experimentally studied. It is shown that the shape of the oscillating curves of the output power versus the elongation length and its depth of modulation are influenced by the fusion temperatures. For a given period of transmission spectrum of a biconical fiber, the required number of oscillations is decreased when the fusion temperature is increased.

The relation of spanned optical spectrum and modulation intensity in a phase modulator is calculated in this paper. The frequency spectrum of 0.6328 μm light driven by 2.45 GHz microwave at 1 W power is analyzed and observed. Finally, with a grating spectrometer, the 0.13 nm spectrum width at 16 W microwave power is measured. The two measured results are in good agreements.

In this paper, a novel hybrid algorithm which combines SA (simulated annealing) algorithm with GA (genetic algorithm) is used to design binary optics elements for ICF (inertial confinement fusion) uniform illumination. GA, which is a parallel algorithm, reserves historical information for SA, while SA′s parameter, temperature, is used to control GA′s convergence. Simulation calculation shows that the hybrid algorithm is effective and robust. A focal spot with a uniformity 3.2%(rms) and an efficiency approximating to 90% is obtained by this method.

In this paper, using a vector diffraction theory, it is shown that the properties of the period, the high transmissivity, the high reflectivity and the polarization spectral characteristics of the subwavelength phase gratings with a finite substrate are associated with the substrate thickness. The application of the gratings would be promising.

A new recording system for generating the multidirectional holographic phase gratings is presented. An adjusting method of the system is discussed in detail. Adopting a method of four light beam exposure at the same time, the diffraction efficiency of the gratings is increased. Theoretical interpretation of the experimental results is outlined.

Five of ferrocenyl organometallic compounds have been synthesized with phase-transfer Wittig reaction and characterized by IR, UV, elemental analysis and 1 HNMR. The crystal X-ray structure and nonlinear second-order optical properties of the compounds have been studied. It is concluded that this kind of compounds have fairly large second-order susceptibility, and that, both donor-acceptor substi-tutes and the extending conjugated area facilitate the nonlinear second-order optical susceptibility.

After the establishment of a heat transfer model of alloy powders irradiated by a laser beam, the temperature histories of different alloys, particle sizes and substrate materials under different laser power levels have been calculated by a finite difference method. Also, the beginning time of melting and the relative critical scanning speed of the alloy powders under different laser power levels are obtained by calculation and verified experimentally.

A new on line light scattering method to determine particle size and concentration is proposed in the paper. The problem of pollution in the observation windows can be well solved with this new method. The experimental results demonstrate that the light scattering method is valid for the on line measurement of the particle size and concentration.

A method of evaluating the beam quality of lasers with unstable resonators, called as β factor method, is studied. The definition and physical meaning of the method are explained and the measuring method is presented.

Finite difference technology and compressible scaling method (CSM) are used to the simulation of the combustion driven CW DF chemical lasers. Different fuels (H 2 and C 2H 4) and different diluents (He and N 2) are calculated. The components of mixing gas in the combustor, small signal gain, line intensity distribution of optical cavity, output power and chemical efficiency of lasing are given. The results showed that: the lasing zone of the DF chemical laser is longer and much easy to adjust when C2H4 is used as fuel and He as diluent, the chemical efficiency is higher, and the line intensity distribution is more converged.

By transmitting a pumping beam through a waveguide located in the H 2 Raman cell, the interaction region of the stimulated Raman scattering and conversion efficiency can be increased in the Raman cell. In this paper, by replacing the original waveguide with a tapered one, the conversion efficiency was further increased in some range of H 2 gas pressure. The results are theoretically analyzed and discussed.

A domestic diode laser pulse pumped Cr:LiSAF tunable laser is reported for the first time. A maximum average output over 2 mW, slope efficiency of 25% and a tuning range from 806.6￣920 nm are obtained. The experimental results are discussed.

An active modelocking technology of fiber ring laser by beat signal feedback is reported. The modulation frequency is self adaptable with the cavity length when an amplitude modulator is driven by the high repetition beat signal extracted from the cavity. The transform limited ultra short pulses of 11 ps with a 2.5 GHz repetition rate have been obtained.

A novel all solid state Nd:YVO 4 laser with a sandwich resonator was reported. Under 7 W of 806 nm fiber coupled diode laser pumping, 3.7 W of 1.064 μm output power was obtained in CW TEM 00 mode with a slope efficiency of 62%. With an intercavity frequency doubling KTP crystal used, 620 mW of green output was achieved with an 11% optical optical efficieney.

The XeF excimer is formed in an excimer laser with surface preionization along a Teflon plate by discharge excitation of a Xe/Ne mixture without additional fluorine donor gases. Emission spectra at central wavelengths 351, 353 and 308 nm are studied. The KrF fluorescence spectrum at 248 nm is observed when a Kr/Ne mixture is excited.

The interaction between intense laser pulses and aerogel targets was studied. The X ray emission and second harmonic generation are different from those of the plane targets. Different plasma status relative to these special targets was studied.

In a Cu:KNSBN crystal, the self pumped phase conjugation changes from the cat′s mechanism to stimulated backscattering and four wave mixing mechanism as wavelength of the pump beam being changed from 514.5 to 488 nm. After it is formed, the self pumped phase conjugation at 488 nm changes from slow fluctuation to a quasi sable state gradually in about 400 seconds, while the phase conjugation at 514.5 nm is always in an irregular flutuation state.

Inner shell dielectronic recombination cross section excitation of Na like Ar 7+ ion is calculated. It is very important for X ray laser. The cofigurations 2p 53p 2 and 2p 53d 2 inner shell dielectronic recombination cross sections are given.

In this paper, sodium iodide molecule dissociation was reported with a pulsed laser at 330 nm, and then one of the dissociated products, Na, was ionized by using resonance ionization method. By analysing time of flight mass spectra (TOFMS) of sodium ion Na +, the feature of Na + mass spectra was studied and the possible multiphoto ionization (MPI) process was discussed.

Following that the nonlinear Kerr media are approximately described by time quadratic index media, a refractive index change with propagation distance is considered, the propagation of the pulse in Kerr media is analyzed, and an asymptotic analytical solution is obtained. Then the temporal imaging of the pulse in Kerr media is discussed.