In this paper, the group velocity delay of several stretchers that are used in chirped pulse amplification laser technology was analysed with geometric optics method. The analytical formulas of group velocity dispersion are given, which are consistent with Martinez's result for the stretcher that he proposed and analysed with Fresnel Kirchhoff integral.

A spatial/wavelength division multiplexed 3×10 fiber Bragg grating sensor array, acted as the reflector of a ring cavity fiber laser, was interrogated by employing a 1×3 optical switch and a tunable F P filter. Demodulation was achieved by using an unbalanced Michelson scanning interferometer that transform the wavelength shift signal induced by the measured strain into phase shift signal. The sensor sensitivity of the system was demonstrated to be 1 6817 Deg/με, which agree with the theoretical value of 1.6843 Deg/με well. A feedback subsystem was introduced to make the system track the measuring channel automatically.

It is proved from the theory and experiment that the liquid crystal tunable filter can be used to select some desired wavelength from a multiline laser. With the tunable liquid crystal filter outside the Ar + laser, the beam of 488 nm under voltage of 1.19 V and 514.5 nm under voltage of 1.30 V can be achieved, respectively.

Using the fractal theory, this paper studies the ILLLIT's effects on the deformity of erythrocyte. The results of theoretical analysis indicate that ILLLIT surely can decrease the elastic modulus of protein, which is advantageous to improve the deformity of erythrocyte.

Different property parameters of practically available table top laser plasma X ray source are analyzed theoretically, and the feasibility of making valuable X ray hologram using these kinds of facilities is proved. On the basis of these achievements, in line holography and image reconstruction are programmed and simulated. Parameters including X ray coherence, signal to noise ratio, source intensity and recording length that can influence experimental result are discussed. Furthermore, the possible methods to reduce exposure time and to acquire higher resolution are studied.

Wigner distribution as a function expressing signal in space and frequency field simultaneously, is caused an extensively interest in the world. But up to now, the main methods reported to obtain the Wigner distribution of 2D signals are through optical ways. The discrete numerical methods reported to obtain Wigner distribution is only limited to one dimension, for the Wigner distribution of 2D signals contain 4D variables (2D space variables and 2D frequency variables), its calculation is intricate, and till now, there is no report of this aspect. In this paper, the discrete calculation method of Wigner distribution for 2D signals is put forward, and the Wigner distributions of 2D real signals (a circle aperture, a ring aperture and a rectangle aperture) are simulated.

In this paper, the stainless stencil with 0 2 mm thickness was cut by Nd∶YAG pulse laser. The effect of laser cutting parameters on surface roughness of kerf, splash and residue of kerf surface was studied systematically. The results showed that with the increasing of repetition frequencies, power density, and pulse width of laser beam and with the decreasing of scanning speed, the kerf quality could be improved. Besides, a formula of estimating the kerf surface roughness was also presented, which can explain the experiment results well.

This paper introduces an equipment for preparation of amorphous alloys, quasicrystal and nanocrystal on the surface of metals, semi conductors and ceramics by use of laser under vacuum condition. The results of laser hardening high speed steel W18Cr4V and laser melting solidifying Al Cu Fe alloys with the employment of it are also reported.

This paper comparatively studies the welding characteristics of two major high power industrial laser-CO 2 laser and YAG laser. By comparing the welding effect differences for the two kinds of lasers, it is shown that the energy efficience of YAG laser welding is bigger than that of CO 2 laser.

In this paper the development of capillary discharge soft X ray laser is introduced. Using XDCH, a one dimensional Lagrangian magneto hydrodynamics code, the simulation results of a discharge pumped 2p 53p→2p 53s transition 46.9 nm laser in Ne like Ar are presented. The physical schemes in Ne like Ar 46.9 nm laser are also studied. Finally the possibility of generating soft X-ray laser from the home made setup is discussed.

To meet the requirement of the high power setup SGⅡ,a set of Q switched and tripling Nd∶YLF laser system for simulating light source is developed, the flash pumped Nd∶YLF laser used Cr 4+ ∶YAG crystal as the Q switch, KTP and BBO crystal as the third harmonic generator. Here a laser output of 0 3510 μm wavelength is got, and can satisfy the need of the SGⅡ system.

An only one ns Nd∶YAG laser pumped narrow bandwidth pulse Ti∶sapphire tunable laser (by 532 nm) and a BBO OPA laser (by 355 nm) is reported. In experiment, a narrow linewidth (<0.1 nm) continuous tunable range of 570～670 nm Ti∶sapphire laser injection seeded BBO OPA with the laser energy output of 6 times in comparison with that of no seeded are achieved.

The impedance characteristics of RF discharge CW laser are studied by measuring the current, voltage and phase angle. The V-I characteristic, impedance and capacitance of the RF discharge plasma changing with the gas pressure and current are given.

Strontium halide was substituted for metal strontium by way of lasing substance, a few of strontium laser oscillations have been obtained including strontium atom self terminating lasing with wavelength 6.45 μm, strontium ion self terminating lasing with wavelength 1.03/1.09 μm, and strontium ion recombination lasing with wavelength 416.2/430.5 nm. The developing foreground of strontium halide laser was prospected.

It was pointed out that the ordered aero optical aberrations in Hydrogen Fluoride (HF) continuous wave chemical laser (CWCL)′s cavity is one of the main factors influncing laser beam quality by the analysis of the inhomogeneous medium in laser cavity. The 2D refractive index model in HF CWCL was set up to simulate the inhomogeneity distributions in main tone/over tone HF CWCL′s cavities in the condition of power/zero power output. With it, the performance and beam quality in 3 Slot (3S) and 2 Slot (2S) structure lasers were computed and analyzed. By the simulation, it was shown that the ordered aero optical aberrations in the telescopic unstable cavity are not significant in nozzles array of 1 m length. But with the increase of the length of nozzles array, it will be important, especially for the over tone HF lasers. In addition, the performance and beam quality of 3S are better than that of 2S.

A cw frequency stability and intracavity frequency doubled ring Nd∶YVO 4/KTP end pumped by a laser diode through fiber coupling is designed and experimentally demonstrated. Using the side band frequency locking technique, up to 1.5 W green output with the frequency stability better than 620 kHz is achieved by the pump power of 11 W. The conversion efficiency from light to light is 13.6% and the fluctuation of output power is less than ±1.5%.

An optimized all solid state single frequency Nd∶YVO 4 laser at 1.06 μm with a mode cleaner was used to pump a optical parametric oscillator consisting of periodically poled LiNbO 3. The near degenerate subharmonic wave at 2.1 μm wavelength was obtained under a pumped threshold of 1.5 mW. The subharmonic output of 0.9 mW was produced at a pump power of 6 mW. The light to light conversion efficiency is 15%.

Transmission properties of Hermit Gaussian optical pulse in the fiber are discussed with moment method when effects of the high order dispersion are considered, and approximate solutions are obtained with Runge Kutta numerical integral method. Compared with numerical simulations, the solutions coincided with numerical simulation results perfectly well.

Semi analysis expressions of various electrical noise terms in distributed fiber Raman amplifiers are derived in this paper, accounting to impacts of Rayleigh backscattering on amplified spontaneous emission (ASE) and double Rayleigh backscattering (DRB) noise. The concept of equivalent sensitivity is introduced in this paper. The impacts of Rayleigh backscattering on the noise performance of distributed Raman amplifier is studied comprehensively by this concept.

By means of the selective trapping and two separated crossed ion beams at right angles, the ground low energy (electron volt) multiply charged Sc n+ (n=1～3) and Ti n+ (n=1～4) ions have been produced from refractory pure metal targets in a RF ion trap. The measured decay rates of Sc 3+ and Ti 3+ are 1.98 s -1 and 0.58 s -1 with the base pressure 5.6×10 -7 Pa, respectively.

The spectral properties of stimulated Raman scattering in ethanol and acetone pumped by broadband chirped pulses are examined. The spectral width of the generated first order Stokes emission is comparable with that of the pump pulse, and the conversion efficiency is also considerably high. Consequently, it is possible to obtain femtosecond laser pulses of about 1 μm wavelength, by a "broadening-SRS-compression" experimental scheme.

Yb∶YAG laser crystals are grown by the Czochralski technique. The specific heat and thermal diffusivity data of Yb∶YAG are measured. It shows that the doping of Yb 3+ ions leads to the decrease of specific heat and thermal diffusivity, especially when the doping concentration is high. And the decrease of the latter is regard as the result of lattice deformation caused by the doped Yb 3+ ions.

The energy intervals, spontaneous transition possibilities and oscillator strengths of forbidden transitions for Be like ions (Z=21～92) have been calculated by relativistic many configurations method with Breit correction, QED correction and nuclear effective volume correction. In addition, Be like ions as a laser media with population reversion by combination mechanism has been discussed.

By using frequency modulation optical heterodyne technique, the frequency of diode pumped Nd∶YVO 4/KTP intra cavity frequency doubling mini laser is locked to Doppler broadened absorption line of 127 I 2 near 532 nm. The analysing of error signal shows that it is possible to make laser frequency stability up to 10 -10 at 1 s average time.