In this letter, numerical simulation and experimental study of a radial-slab solid-state laser are presented. The laser includes four crossing-slabs pumped by four Xe flashlamps. The numerical simulation of coherent intensity in the near field and the far field indicates that the laser with the structure can improve the quality of output beam compared with incoherent beam combination. The radial-slab solid-state laser is fabricated, and initial experiments are carried out at a pulse repetition of 1 Hz. Nine beams in the near field and one combined beam in the far field are obtained in our initial experiment. The experimental results are consistent with the numerical analysis in the coherent condition. The results show that coherent beam combination is obtained by this laser.

A periodically poled lithium niobate (PPLN) optical parametric generator (OPG) pumped by a laser diode (LD)-pumped Q-switched Tm,Ho:GdVO4 laser operated at 2.048 \mum with pump pulse of 25 ns and repetition rate of 10 kHz is reported. A continuous tunable middle-infrared (mid-IR) spectrum of 3.88~4.34 \mum is obtained by changing the crystal temperature from 50 to 124 oC. When the incident pump power is 3 W, the total OPG output power is 95 mW, corresponding to optical conversion efficiency of 3.2%.

A low-threshold middle-infrared (mid-IR) MgO:PPLN optical parametric generation (OPG) pumped by a laser diode (LD) end-pumped Z-type Nd:YLF laser at 1047 nm is realized with high reflectivity(HR) mirror for signal. At repetition rate of 10 kHz, the OPG threshold of 50 'mu'J has been achieved with HR mirror for signal. Compared with the threshold without mirror, the threshold decreases by 17%. Using HR mirror for pump at output side of crystal, the threshold of 40 'mu'J is achieved. The 2.7-4.1 'mu'm continuous tunable output is produced with seven grating periods from 28.5 to 31.5 'mu'm and temperatures from 30 to 200 . When the incident average pump power is 3 W, the OPG idler output power is 0.46 W at 3.26 'mu'm, which corresponds to optical-to-optical conversion efficiency up to 15.3%.

A periodically poled magnesium oxide-doped lithium niobate (5 mol% MgO:PPLN) intracavity optical parametric oscillator (OPO) pumped by a diode-pumped Q-switched Nd:YLF laser operating at 1.047 microns is reported. A broad continuous tunable middle-infrared (mid-IR) spectrum of 2.69-4.07 microns is obtained by changing the crystal grating periods from 28.5 to 31.5 microns. When the diode pump power is 8 W, the intracavity OPO operating at a repetition rate of 10 kHz produces average output power of 0.42 W, corresponding to conversion efficiency of 5.2% from the laser diode pump to OPO idler output.

A set of fiber-coupled continuous wave (CW) diode lasers has been used to pump Tm,Ho:GdVO4 and generate 2.048-μm laser radiation at liquid nitrogen temperature. The optical-optical efficiencies of 25%, output power of 3.5 W, and pumping threshold of 838 mW have been obtained and compared with those from Tm,Ho:YLF under identical experimental conditions.

At liquid-nitrogen temperature, at 10-kHz pulse repetition rate, Q-switched 36-ns pulses with average output power of 4 W at 2.05 um and 4.5-W continuous wave output power with a total optical-optical conversion efficiency of 30%, were achievedfrom a 6% Tm, 0.5% Ho:YLiF4 laser. This laser was end-pumped by a fiber-coupled laser diode emitting up to 15 W around 792 nm. The 1-m-long optical fiber carrying the pump radiation has a core diameter of 700 um with a numerical aperture of 0.22.