The waveguide length in Raman beam cleanup system is calculated, considering various factors such as the pump depletion, gain decrease due to dispersion and inclined incidence and pump distortion. The calculating results are compared with the experimental data. This shows that the optimal length of waveguide should be the minimum value among various limitation.

The quenching mechanism was studied in a quenched dye laser pumped by excimer laser. For some pump pulses, the quenching effect of the quenched laser was analyzed by laser rate equations. The effects of equivalent delay time of cavity, pumping strength and rising front of pumping pulses on quenching were studied. The cause of formation of laser peak signal was explained and some important parameters of the lasers were discussed.

Based on quantum theory and multimode model, concerning the pump depletion, the second-order quantum correlation as the function of interaction distance in stimulated Raman scattering (SRS) was calculated and analyzed. The analysis predicts that, in the absence of dispersion, the correlation between Stokes waves and the pump increases to unity while the increase rate depends on the ratio of the pump and input Stokes. The results agree with the Raman generation theories and the semiclassical theories.

The colliding pulse mode-locking of Nd:YAP lasers which have a plane-convex unstable resonator was investigated at 1.3414 μm. The experimental results showed that the mode-locked output energy reached 57.3 mJ (the biggest pulse in the pulse train was more than 8 mJ), with pulse duration of 78.7 ps. The stability of the dye solution was also investigated.

The short laser pulse with pulse duration of about 2ns and pulse energy of 0.6mJ was obtained in a quenched dye-laser pumped by a KeF excimer laser. The dye Coumarin 498 dissolved in methyl is used as the active medium in the quenched dye laser. The experimental results on the dye-laser show that (1) its energy fluctuation is within 7% under the condition that the output energy of the excimer-laser is within 5%, therefore, the operation of the dye laser is very stable; (2) its spectral tunable range is only about 1.5nm; but if the loss of the quenched dye-laser decreases, its tunable range will increase; and if the working temperature of the dye-laser system changes, its wavelength will change also (change of 1��C in temperature corresponds to change of 0.1nm in wavelength).

This paper described a dye laser with zig-zag cavity pumped symmetrically from two sides by a 308 nm XeCl excimer laser. The intention for improving the output beam was investigated by using symmetrical pumping from two sides. The experiments show that the quality of the output beam is better than that by using ordinarily transversal pump. For dye coumarin 460 dissolved in methanol with 2��10-3 mol/l concentration, energy conversion efficiency is 11.7% at the wavelength of 460 nm. Moreover, the similar experimental results are obtained when other dyes, such as PTP, coumarin 498 are used.

In this paper, the quenched dye lasers pumped by XeCl and KrF excimer lasers were investigated theoretically and experimentally. Dye laser pulses with duration of 0.8 ns for XeCl laser pumping and 2 ns for KrF laser pumping were obtained.

In this paper, a single pulse with pulse duration of 40 ps and 0.2 mJ pulse energy was generated in a quenched dye laser system pumped by a KrF laser.

The effects of group-velocity dispersion in an SHG crystal on the evolution of optical pulses in a mode-locked laser by a nonlinear mirror are analysed. The pulse duration is determined by the balance between pulse stretching due to the group-velocity dispersion of the SHG crystal and pulse shortening due to the intensity-dependent reflection coefficient of the nonlinear mirror. Theoretical calculation shows that the final pulse duration is mainly confined by the group-velocity mismatch of the fundamental and the second harmonic in the nonlinear crystal.

A method to obtain short pulse in an excimer laser was presented in this paper. The theoretical mechanism of ultrashort pulses generation in quenching dye lasers was briefly described. The experimental setup consisting of a quenching dye cell, two dye laser amplifier, three spherical lens, three cylindrical lens and a grating was schematically given out. For dye coumarin 498, single pulse with 1 ns pulse width and 1.1 mJ energy is demonstrated at 496 ns experimentally. Because of its simple structure, low cost and easy operation, the quenching dye laser is worth investigating.