Electro-optic Q-switched diode pumped solid-state laser (DPL) with corner-cube,cross-resonator optical parametric oscillator (OPO) (CRO) and the technology of polarization controlled by electricity are used to acquire the output of dual-wavelength of 1064 nm and 1570 nmin the conditions that the laser must be smart and light,and have high reliability,high efficiency,high recurrence-frenquency and large power output.Experiment gets laser pulse with 200 mJ each pluse at 1064 nm and 74 mJ each pluse at 1570 nm,and conversion efficiency of 45% together with output of stable orientation,so that it can be used as airborne,spaceborne,ship laser location,irradiation or radar,and used in the field of laser environmental monitoring.

An optical parametric oscillator (OPO),which is pumped by a Nd:YVO4 laser with the 1064 nm wavelength,is obtained based on PPMgLN.For the continuous wave (CW) operation mode,the threshold is only 1.1 W and the output power of idler at 3.2 μm is 905 mW.For the active Q-switched operation mode,the average output power at mid-infrared wavelength is 1.13 W,which corresponds to an optical-optical conversion efficiency of 17%.For the passively Q-switched operation mode with a Cr:YAG saturable absorber in the cavity of Nd:YVO4 laser,the average output power of idler from OPO at the mid-infrared wavelength is 125 mW.By changing the periods of the domain structure on the PPMgLN wafer,a widely tunable mid-infrared spectrum from 3.13to 4.20 μm is obtained.

The experimental results of continuous laser diode pumped Nd:YVO4 ring cavity configuration single frequency laser are reported.To reduce the influence of heat effect in laser,a new pump configuration is designed and better results are achieved.At room temperature,1064 nm single frequency laser with the power up to 9.9 W is obtained from pump power of 22.5 W.Optical-optical conversion efficiency is about 44.1%.Beam quality is M2x=1.14 and M2y=1.12.Frequency excursion is 83.7 MHz in one minute.Instability of output power is less than 0.5% in 7 h.

Coherent beam combination of Yb-doped fiber laser array is studied experimentally by spatial filtering to passive phase locking.The system of coherent beam combination by Yb-doped fiber amplifiers array in two-dimensional distribution is built.The four polarization maintaining Yb-doped fiber amplifiers are developed.By optical feedback of in-phase signal,the in-phase output of all amplified lasers is achieved and two-dimensional far-field stable interference pattern is obtained.The coherent contrast ratio is up to 91.7% and coherent coupling efficiency is 94.5%.Coherent output of multi-longitudinal modes is also observed in phase locking.

A Q-switched repetitive mini laser is developed by requirement of high beam-quality.The interrelations between the parameters of variable reflectivity mirror (VRM) and con-focal unstable resonator and their effects on laser intensity distributions are analyzed.A suit of resonator parameters is obtained to meet high beam-quality of outputting.In order to develop a mini adjust-free laser,a folded resonator is designed,where a cube corner prism is used as the folded mirror.Because linearly polarized light exists in the resonator,the laser can be run with an electro-optic Q-switch in a special polarization azimuth.Based on these theory analyses,an amount of experiments have been done.Using a xenon flash lamp with 32.4 J as the pump energy,single pulse laser output of high beam-quality and high dynamic to static ratio light spot is obtained,and its repetitive frequency is 1-10 Hz.When the laser works at the repetitive frequency of 3 Hz,an energy of 320.2 mJ,pulse width of 8.3 ns output beam is achieved,and its efficiency of the Q-switch is 95.5%,while the electro-optical efficiency is 0.99%.

The terahertz (THz) laser pumped by all-metal radio frequency (RF) waveguide CO2 laser is designed and researched.Its working gas is CH3OH .The pulsed THz laser output is obtained with the pump of P9(36) CO2 pulsed laser(9.69 μm).The THz laser waveform and pulse repetition frequency (PRF) for the pumped laser and THz laser are measured in experiment.The relationship between laser intensity and working gas pressure is also given.The PRF can be up to 5 kHz for the pumped laser detected by HgCdTe detector with high bandwidth.The THz laser is measured by pyroelectric detector and the measured waveform is distorted and the maximum PRF is only 1 kHz due to the limitation of the detector.The relationship between THz laser intensity and working gas pressure is also studied and the best working pressure is about 10 Pa.The designed THz laser has all-metal structure,which needs no water cooling.It has the advantages of simple structure and small size,which are helpful for further researches.

The dependences of all-solid-state tunable Ti:sapphire laser output poweron the resonator intracavity losses and output coupler transmission were analyzed theoretically and tested in experiment.According to the experimentally tested intracavity losses and transmission,the design of the laser was optimized and higher and more stable output powers were obtained.With the pump power of 8 W,the output power of 2 W at the wavelength of 792 nm with slope efficiency of 37.6% was obtained.The intensity fluctuation of the output laser was less than ±0.5% during 1 h,and the tunable range was from 720 to 820 nm.When the laser was locked,the frequency stability was better than ±134 kHz over 10 s and ±3.3 MHz in 15 min in the totally tunable range from 720 to 820 nm.

High power operation of single-frequency Raman fiber amplifiers (RFA) is usually limited by the onset of stimulated Brillouin scattering (SBS).We present our theoretical investigation on RFA limited by SBS,based on the intensity equations combining SBS and stimulated Raman scattering.The influence of temperature gradients and strain gradients,which can broaden the SBS gain profile and thereby increase the SBS threshold,on the performance of RFA is discussed.Although tensile strain and temperature gradients can suppress SBS in RFA separately,the conditions are too rigorous to realize.A feasiblescheme for suppression of SBS in RFA is proposed using the temperature gradients together with tensile strain gradients along the fiber length,resulting in an increase of about 3 times of amplifier output power.The results of simulation provide a guide to suppress SBS in high power single-frequency RFA.

One kind of conductively-cooled,double-edge-bounce-pumped and pulsed Nd:YAG double-stage slab laser amplifier is reported.When the amplifier operates in pulsed condition,its high efficiency,good beam quality,compactness,weak thermal effects and high scalable gain are proved by the tests of the input-output relationship,beam quality and thermal effects and so on.The pulsed laser generated by a seed injected single-frequency oscillator,whose power is 1.1 W,pulse duration is 11.3 ns and beam quality factor (M2x,M2y) is 1.2,is amplified by the amplifier at the repetition frequency of 125 Hz and high-beam-quality output laser,whose power is 24.1 W,pulse duration is 8.9 ns and beam quality factor M2x is 1.53,M2y is 1.27,is obtained.Experimental results show that this kind of laser amplifier has great potential in the application of space detection.

The master-oscillator power-amplifier chain is an efficient method to obtain high power pulsed dye laser.The timing match between pumping and dye laser pulses is one of the main conditions to realize high extraction efficiency.The dye laser amplifier forward longitudinally pumped by a high-pulse-repetition,Q-switched and frequency-doubled Nd:YAG laser is simulated with rate equation model.The temporal characteristics of pulse amplification are presented with real pumping and dye laser pulse shape,where the pumping laser pulse width is longer than dye laser′s.The simulation results show that there is nanosecond delay between pulse peak of dye laser pulse and that of pumping laser pulse.The results also show that the amplified dye laser pulse is widened by the process of excitation,stimulated emission,and re-excitation of dye molecules when the pulse width of pumping pulse is wider than that of dye laser pulse.The analysis indicates that it is feasible to timing control with the method of keeping pumping pulse peak position stable.

A novel tunable Fabry-Perot (F-P) filter was developed to meet the requirement of high power tunable fiber lasers.It consisted of two fiber collimators,a cavity length tunable F-P cavity and a piezoelectric transducer (PZT).By changing the voltage applied to PZT,the length of F-P cavity could be tuned finely.A wide tunable wavelength range of 50 nm was achieved with a fineness of 134.The developed F-P tunable filter was used to construct a ring-shaped tunable Yb fiber laser,using Yb3+-doped fiber as the gain media.A tunable range of 32.5 nm was realized for the laser output,covering the wavelength between 1032.82 and 1065.32 nm.The maximum output power of laser was 2.72 mW with a linewidth of 0.078 nm.

The explicit analytical expressions of pump absorption efficiency,slope efficiency,fundamental-wave geometric average intensity in cavity,laser threshold,output laser intensity and power for longitudinally-pumped quasi-three-level continuous-wave lasers have been derived using the rate equations and optical transmission equations in cavity.Furthermore,the influences of laser-induced pump absorption saturation effect on pump absorption efficiency,laser threshold,conversion efficiency and fundamental-wave geometric average intensity in cavity are discussed.Theoretical analysis and numerical simulations indicate that the influences of the pump absorption saturation on the performance of lasers relate to the ratio of the pump absorption cross section and laser stimulated emission cross section,the average single-pass loss factor,the population factors of pump energy level and upper and lower laser energy levels,length of laser crystal,etc.When the laser crystal is shorter,the average single-pass loss factor is larger,the ratio of pump absorption cross section and laser stimulated emission cross section is larger,and the pump absorption saturation effect is more obvious.The decline of the pump absorption efficiency results in the increase of the laser threshold and the decrease of the fundamental-wave geometric average intensity in cavity and laser conversion efficiency.

High repetition rate and high energy laser is realized by two-stage pre-amplifiers and two-stage main amplifiers seeded by a pulsed diodes pumped EO Q-switched single-longitudinal-mode laser with pulse repetition rate up to 1000 Hz.Detailed experimental investigation on stimulated Brillouin scattering reflectivity of a large aperture fused silica fiber is carried out using this laser source.Reflectivities of 33.3%,41.2% and 50.7% are achieved at the repetition rate of 1000,500 and 400 Hz respectively.The tapered fiber′s core diameters are 1 mm and 400 μm for its two end surfaces.More than 50% stimulated Brillouin scattering reflectivity with such high repetition rate and high energy is realized.At the repetition rate of 400 Hz,the pulse duration is compressed to 6 ns from 24 ns,with a compression ratio of 4:1.The pulse shape is free of modulation.

A ytterbium-doped large mode area photonic crystal fiber (LMA PCF) femtosecond laser dual-stage amplifier is experimentally studied.Single polarization LMA PCFs are used in the oscillator and pre-amplifier,while a 7-core LMA PCF is used in the main-amplifier.The seven cores are arranged in array type with a mode field area up to 5000 μm2 which effectively suppress the nonlinearity in the fiber.In addition,the heat and stress induced beam distortions are reduced because the cores are discrete distributed.At low pump power,the output features a complex beam profile resulting from a superposition of several supermodes.Flat in-phase supermode and Gaussian-shaped far-field distribution are realized under high pump power.Average power of 24 W laser pulses at a repetition rate of 1 MHz are obtained.The pulses duration can be compressed to 110 fs with peak power up to 150 MW.

Based on the modified coupled-wave theory,the emission characteristics,including threshold gain,photon density distribution in the cavity,external differential quantum efficiency,ect.for second-order distributed feedback (DFB) lasers are investigated.Numerical simulation results also show that for given device structure with wavelength of 1.55 μm,grating duty cycle has certain influence on the emission characteristics.Finally,optimal grating duty cycle of 0.43 and optimal results include uniform photon density distribution along the cavity,the side-mode suppress ratio as high as 35 dB and external differential quantum efficiency of 47% are obtained.

Near diffraction limit 2.68 μm laser is obtained by intracavity KTP optical parametric oscillation (OPO) pumped by a 1064 nm laser.The experimental results are analyzed in detail.The pump source is an acousto-optical Q-switched Nd:YAG laser,and the OPO is doubly resonated.Two identical KTP crystals are placed with opposite optical axis to compensate the walk-off effect.The crystals are cut as φ=0°,θ=62° to generate 2.7 μm laser.To utilize the large effective nonlinear coefficient,the phase-matching is based on typeⅡ (o→o+e).When the pump power of the 808 nm laser diode is 330 W with a repetition rate of 7 kHz,an average output power of 7.6 W at 2.68 μm is obtained.The output power of the corresponding signal laser of 1.765 μm is about 14 W and the beam quality factor M2 of 2.68 μm laser is less than 1.6.

In the W type cavity,a laser diode-pumped passively mode-locked Yb:YSO laser is demonstrated with semiconductor saturable absorber mirror (SESAM).At the pump power of 13.5 W,the average output pulse power is 2.39 W,and the repetition rate is 104 MHz.The actual pulse width is 3.2 ps,the center wavelength is at 1043.5 nm,and the full-width at half-maximum of the spectrum is 1 nm.

High repetition rate short pulsed seed laser output at the wavelength of 1910 nm is achieved by utilizing the home-made Tm-doped YLF(Tm:YLF) crystal.The crystal size is 1.5 nm×6 nm×20 mm,and the doping atom fraction is 2%.With the cavity length of 90 mm,by employing different transmissions (T) and radii (R) of the output mirrors,the highest slop efficiency of 25.6% is obtained with T=10% and R=250 mm.In addition,pulsed laser is amplified based on the main-oscillator power-amplifier (MOPA) system by using high-power Tm-fiber amplifier.With the pump power of 100 W and repetition rate of 500 Hz,the laser output with the peak power of 630 kW and pulse energy of 63 mJ is obtained.

A tunable TEA CO2 laser with tubulous preionizer is developed.With optical bridge and folded cavity,laser is compact and stable.Tunable laser output is realized by grating resonator.73 lines of the CO2 molecule rotational transition which wavelengths range from 9.19 to 10.86 μm are obtained,and there are 45 lines whose pulse energies of laser radiation exceed 2 J.The maximum pulse energies of P10(20),R10(20),P9(20),R9(20) are 5.3,5.4,5.5 and 5.1 J with the corresponding electro-optical efficiency of 9.6%,9.8%,10.0%,9.3%;The maximal electro-optical efficiency of the above four lines are 10.3%,10.7%,10.7% and 10.7% respectively.Under the gas pressure of 30 kPa,the maximal specific injection energy is 2.626 J/(L·kPa),and the maximal specific output energy of P9(20) is 0.205 J/(L·kPa).Laser pulse waveforms of the above four lines with different gas pressures are measured;The output pulse widths vary from each other,and the width of R9(20) is the largest.The far-field divergence angle is 2.6 mrad.Tunable high repetition laser output is realized at the repetition rate of 190 Hz.

Using a 248 nm KeF excimer laser as the UV light source,the inscription method of fiber Bragg grating (FBG) on large-mode-area double-clad fiber (LMA-DCF) was studied with phase mask technique.The center wavelength of the fabricated FBG was at 1076.11 nm with a 3 dB bandwidth of 0.32 nm and reflectivity of 99.9% in the fundamental mode.The FBG was then applied to a Yb3+-doped double-clad fiber laser as a highly reflective cavity mirror.The 144 W of stable output power with a slope efficiency of 60% was achieved.The spectral characteristics of the output laser matched well with that of the FBG and an excellent Gaussian beam shape was achieved.

A passively mode-locked Nd:YAG laser with a partially reflective semiconductor saturable-absorber mirror is reported.According to the well known ABCD matrix theory,the astigmatism and the stability in the cavity of the laser are theoretically analyzed.Stable continuous-wave mode locked pulses are achieved with a Z-type resonator.The average output power of 372 mW is obtained with the incident pump power of 7.7 W.The pulse duration is measured to be 8.9 ps with a repetition rate of 54 MHz at the central wavelength of 1064 nm.

The thermal effect of 946 nm laser generated by laser-diode (LD) pumping the columniform Nd:YAG crystal is analyzed.After considering the quasi-three-level structure of the crystal and the distribution of transmission power in the cavity,a more actual temperature field in the crystal is obtained by revamping the heat conversion coefficient.The temperature of the crystal facet center becomes 246.7 ℃ from the previous 156.83 ℃ before revamping the parameter and increases 89.87 ℃.The thermal focal lengths before and after revamping the parameter are calculated and measured.The experimental result accords with the theoretical result basically.The method can be applied to the laser thermal effect research of quasi-three-level and three-level.The analysis and the result can be referred to the thermal effect research of the solid state laser end-pumped by the LD and the optimal design of resonant cavity.

It is an effective method to achieve high power,high efficiency fundamental mode laser output that adopting laser diodes double-end-pumped composite crystal configuration.By employing YVO4-Nd:YVO4-YVO4 composite crystal as gain medium and introducing unsymmetrical plane-plane resonator configuration for achieving effective fundamental mode operation,we obtain 34 W CW fundamental mode output power with a pump power of 70 W and an optical-optical conversion efficiency of 48.6%.The laser pulse width reaches 80 ns in acousto optically (AO) Q-switched mode operation,which might be too long for later applications.After shortening the longer arm of resonator,we obtain 30 W CW fundamental mode output power with a pump power of 66 W and an optical-optical conversion efficiency of 45.5%.In the Q-switched mode operation,quasi-CW output with pulse repetition rate from 10 to 200 kHz can be obtained.The relationships of the average power,the pulse width and the peak power versus the pulse repetition rate are investigated in detail.With the pulse repetition rate of 10 kHz,we obtain an average power of 19.3 W with a pulse width of 28 ns,corresponding to a peak power of 68.9 kW.With pulse repetition rate between 100 and 200 kHz,the average power holds at about 27 W and pulse width about 50 ns.Additionally,the analysis on the resonator design and experiment results shows that further optimization for achieving much shorter pulse width and higher peak power is possible.

A high pulse energy femtosecond laser amplifier with Yb3+-doped single polarization large-mode-area photonic crystal fibers (LMA-PCF) is demonstrated.Based on the nonlinear amplifying configuration,amplification of laser pulses in the LMA-PCF is accompanied by spectral broadening and nonlinear phase-shift accumulation due to the self-phase modulation.This configuration can often help to produce high-peak-power ultrashort laser pulses,since the self-phase modulation induced nonlinear phase shift can be compensated by an appropriate negative-dispersion component following the amplification stage.This strategy of ultrashort laser pulse generation requires,however,a precise balance between the gain,nonlinearity,and high-order dispersion in the oscillator-amplifier system.An acousto-optical modulator is applied to reduce the repetition rate to 1 MHz.Laser pulses with 124 fs duration(the shortest pulse) are generated with 1.56 μJ pulse energy,corresponding to 12.6 MW peak power.

A 15.5-W average power,5-kHz repetition rate laser diode(LD) pumped all-solid-state 589 nm yellow laser was reported.Two acoustic-optic Q-switched LD pumped Nd:YAG lasers of 1064 nm and 1319 nm were used as the basic-frequency lasers.The 589 nm yellow laser was generated by extra-cavity sum-frequency generation(SFG).To get high SFG efficiency,the power ratio and pulse widths of 1064 nm and 1319 nm were optimized.Moreover,the electronic delay technology was employed to make the two lasers time-synchronization.When the total power of 1064 nm and 1319 nm was 140 W,the output power of 589 nm laser was 15.5 W at the matching temperature of 43.5 ℃.The conversion efficiency of SFG was about 11.1%.The repetition frequency of the laser was 5 kHz with the pulse width of about 110 ns.

Working on a discharge-driving continous wave(CW) HF chemical laser,using the oscillating threshold condition and Rigrod theory,and considering with the data of overseas′ HF overtone chemical laser,the overtone cavity mirrors with band selectivity coating were chosen to study.3.5 W of overtone laser is obtained on the 1mm downstream station of H2 injecting orifices.The spot size at 60 cm distance is about 10 mm×7 mm,and the overtone efficiency is 10%.The spectra contain lines P20(6) and P20(7),and the mode is TEM00.There is a little of fundamental laser going with overtone laser.The analysis of results indicates that this is mostly because of the bad coating of mirrors,which is also one of the difficulties to obtain the HF overtone laser,recently.When studying this experiment again,the laser only obtains many watts of fundamental power,the spectra contain lines P2(3) and P2(4).And the possibility reason is optical coating degradation of resonator mirrors.

High power vertical cavity surface emitting laser (VCSEL) array with small divergence angle is reported.By choosing the large aperture size and enlarging the centre spacing of the elements,the resistance and thermal resistance of the array are reduced.The two-dimensional 4×4 array with element mesa diameter of 250 μm,oxide aperture of 200 μm and center to center spacing of 280 μm has a higher output power than that of the single device which has the same active area.The maximum output power is 1.81 W at a current of 6 A at room temperature.The threshold current is 1.2 A with a slop efficiency of 0.37 W/A,and the differential resistance is 0.01 Ω.The causes of the higher order transverse mode in the array element are analyzed by simulating the current density profiles in the active region.The far-field divergence angle is suppressed from 30° to less than 15° by using an extra Au layer.There is a slight drop in output power due to the introduction of the extra Au layer.The aging test is carried out under constant current mode at 60 ℃ and the result shows that the total degradation of output power is less than 10% after 800 h.

In this paper the background and undergo of first emergence of lasers in the world and in China have been briefly introduced.The main development of laser technology in early period (1961-1967) in China has presented,and the measures for promoting this development of laser technology,given by our government,have been emphasized.The achievements of research and development of laser technology in early stage gave the great and deep influence for next years.

Against the background of the first,second and third leaps in the field of semiconductor lasers,a thorough account and analysis is given on the major breakthroughs and developments of the semiconductor lasers in China.

This paper has reviewed the development history of laser glass in China since its invention in 1961.The properties and applications of several commercial Nd:phosphate high power laser glasses used in facility of inertial confinement fusion have been described.The performance of rare earth ions doped multi-component glass fibers applied in generation and amplification of laser has been introduced.

The invention,progress and prospects of laser fusion (mainly SG laser driver systems) are summarized.

In order to commemorate the fiftieth anniversary of laser,this thesis introduces the historical background and theoretical basis of borate nonlinear optical crystals.

There are three major revolutionary milestones in the laser field:the invention of solid-state lasers and gas-state lasers in 1960,the invention of bipolar semiconductor lasers in 1962,and the invention of unipolar quantum cascade lasers (QCLs) in 1994.Currently,mid- and far-infrared unipolar QCLs cover 2.63-360 μm wavelength,continuous wave operation at room temperature with power up to watts.This paper gives an overview on the invention of the QCL and research progress in its theory,materials and devices.The article also discusses the current research status and the future development of QCLs and their applications in emerging strategic areas,including environment and climate monitoring,medical imaging and testing for disease diagnosis,communications,and homeland security.

The history of coherent beam combining is briefly summarized,the newest development of coherent beam combining of fiber lasers is analyzed,and several important trends of coherent beam combining are pointed out,which can be a reference for future development of laser technology.

The output power of fiber lasers increased very fast during the past decades,more than kilowatt can be obtained from single fiber laser.In order to further increase the output power,the core diameter should be increased to avoid the damage of the core surface,but the beam quality will be decreased.In this paper,two methods are introduced:one is to design the large mode field fibers and another is increasing the core diameter with new technology to improve the beam quality.Some experimental results are given in detail.

This paper reviews the development of X-ray free-electron lasers (XFELs).With the unprecedented characteristics of flexible wavelength tunability,high brightness,ultrashort pulse duration,and fully transverse coherence,these accelerator-based X-ray light sources will open new fields in physics,chemistry,material,and life sciences.Based on the present status of XFELs in the worldwide context,the future directions are analyzed.Abrief summary of the developments of free-electron lasers (FELs) in China is given.

The fundamental characteristics of excimer are introduced briefly and the historical development of excimer lasers is reviewed.The progress of excimer technology especially for discharge pumped excimer lasers is presented detailedly.The key technologies recently employed to improve the performance of excimer lasers for lithography are analyzed.The applications of discharge pumped excimer lasers in industry,medicine and scientific research are also discussed.

The soft X-ray experimental platform is constructed for accurate calibrating detector of inertial confinement fusion (ICF) on Beijing synchrotron radiation facility (BSRF).It is the only one in our country.The platform mainly consists of two synchrotron radiation beamlines (energy range:0.05-6 keV),high precision reflectometer,X-ray standard detector of ion chamber,and some calibrating devices for the detector.The soft X-ray beamline (4B7B) andmiddle X-ray beamline(4B7A) are constructed successfully.Their targets and parameters are achieved and excel the original designs.A lot of detectors are calibrated with the platform.They are X-ray detector (XRD),mirror and multilayer,filter,transmission grating,charge coupled device (CCD),and other new type of detecting elements and devices,such as crystal and image plate,with which lots of achievements are obtained in ICF experiments.The platform also has many applications in other fields such as optics,material,astronomy,metrology,and Z-pinch′s detector calibration,etc.

Laser-diode pumped passively Q-switched solid-state lasers,with compact configuration,excellent beam quality owing to good match-up of pump and laser light,easy to achieve sub-nanosecond pulse width and high peak power, have widely applications in laser processing,telecommunications,surgery,biology,material microstructure analysis and so on.In the past decade,dramatic progresses have been made in passively Q-switched solid-state lasers based on ytterbium doped laser material and saturable absorber such as Cr4+:YAG,semiconductor saturable absorber mirror (SESAM).Passively Q-switched Yb3+ doped solid-state lasers have achieved not only the same high peak power output,but also with better efficiency and flexible designs.The progresses and future work on passively Q-switched Yb3+ doped laser materials microchip lasers have been overviewed.

The applications for high-power ultraviolet (UV) lasers are introduced.The principle for the generation of ultraviolet lasers and the performances of nonlinear optical crystals used for high-power ultraviolet lasers are reviewed.The research progress on the high-power all-solid-state 355 nm and 266 nm ultraviolet lasers at home and broad are given.The problems and probable techniques for the development of the high-power all-solid-state ultraviolet lasers are previewed.