The velocity distribution of atoms in an yttrium atomic beam was measured by using laser induced fluorescence. Its most probable velocity was 820 m/s and the FWHM was 510m/s. The temperature of the yttrium atomic source was estimated to be 1587 K from the iso-entropie relation.

Using the sputtered a+oms of a short pulse and high repetition rate uranium hollow cathode lamp as vapour source, a CW dye lasar as exciting light, and detecting with fluorescence method, we have measured the time constant of decay in the ground state and the lifetime in the metastable state of U atoms in HCD lamp.

In the experimental arrangement of perpendicularly polarized light interference, the electro-optic coefficients of crystals relative to γ63 of DKDP crystal are measured by compensating the change of optical path caused by the electro-optic effects of crystals with that of a DKDP crystal. A simple and highly sensitive method for measuring electro-optie coefficients of crystals is proposed.

A ZnSe phase retarder is developed, which can conrest linearly polarized CO2 laser light into circularly polarized light by using pile-of-plates as polarization analyzer, This element has the features of non-deliquation, laser damage threshold being greater than 40MW/cm2, long lifetime, and high conversion efficiency in the wavelength range between 0.60-14μm.It has been used in high-power laser systems.

Using a complex analytical signal representation,the free-space propagation properties of ultrashort pulsed Bessel-Gauss beams whose waist width is independent of frequency are studied.It is found that within the diffraction-free range the transversal intensity distribution of ultrashort pulsed Bessel-Gauss beams remains nearly unchanged,and the on-axis temporal pulse forms broaden along the propagation.Beyond this range,there is a remarkable spreading of the transversal intensity.With the increase of the propagation distance,the on-axis blue shift increases firstly,then gradually decreases after reaching its maximum,and finally approaches an asymptotic value.For example,for a single-cycle ultrashort pulsed Bessel-Gauss beam,the on-axis blue shift increases and reaches a maximum value of 0.50 fs-1,then decreases gradually,and finally approaches an asymptotic value of 0.16 fs-1 in the far field.

The effect of third-order nonlinearity on the second harmonic generation of ultrashort pulses in KDP crystal is analyzed theoretically.It is found that the influence of third-order nonlinearity on conversion efficiency becomes dominant when the incident intensity is above 100 GW/cm~2.A novel approach in which an initial phase-mismatch is introduced to compensate for third-order nonlinearity effect is proposed.The calculated results show that for a 50 fs pulse and a 250 GW/cm~2 input intensity,the conversion efficiency is increased by a factor of 1.1 at the condition of 0.9 mrad initial phase-mismatching angle.At the same time,the fluence modulation of the fundamental and second harmonic pulses due to third-order nonlinearity is suppressed effectively and the temporal profiles are improved.

A new method for phase display using a rainbow hologram recorded with striped-speckle screen is presented. The characteristics of this method and the results of the experiment are also described.

The physical and mathematical model of a ring caviy monomode CO2 laser is set up. The results of linearized stability analysis show that the dynamic instability on the region of low output intensity will appear only when the Debye relaxation rate exceeds greatly the longitudinal relaxation rate of atoms. The numerical calculation of time-dependent solutions reveals the periodic, period-doubling and chaotic behaviour.

The lateral spread current distribution of the terraced substrate semiconductor lasers is derived and a new model is put forward for analysing the stationary characteristics of TS lasers TS double heterojunction and TS large optical cavity structure are analysed and compared based on this model. The theoretical results confirm to the expe-rimental data from some published papers.

The theory and calculation results of the free electrons generated by picosecond light pulses at 1.064μm in semi-insulating GaAs are presented, and the variation of the spatial Fourier components of the free-electron density from deep levels and two-photon absorption versus the intensity of excitation pulses is discussed.

Major properties and the fabrication techniques of CSP A1xGa1-xAs/GaAs single mode laser diodes are reported.

Experimental results are reported by using a 50mm diameter type II matched KDP crystal and a tandem KDP crystal for frequency doubling. Overall energy conversion efficiency up to 70% and 67% have been measured at an input laser intensity of 2.8 GW/cm2 for the monolithic and 2.2GW/cm2 for the tandem doubling respectively. The experimental results are analysed and discussed.

The temporal and spectroscopic characteristics of multi-order SRS pulses, pumping pulse, and their temporal separation in quartz quasi-monomode optical fiber are reported for ps pumping pulses. High conversion efficiency (over 80%) of SRS is found experimentally at high pumping power,and the place for SRS generation is close to the input end of the optical fiber (1.5m). Almost continuous orders of SRS spectrum have been observed for a 63m long optical fiber.

Spectral properties of a novel phonon-terminated laser crystal Y3(In,Ga)2 Ga3O12:Cr3+ grown by flux method are reported for the first time. The results show that the spectral properties of Y3(In, Ga)2Ga3O12:Cr3+ crystal are compatible to those of Gd3(Se,Ga)2 Ga3O12:Cr3+ ,it is a potential ambient temperature tunable laser crystal.