Structural Improvement And Performance Optimization Of A Coupling Device For Fundamental Frequency Laser Amplifier And Doubler Crystal Prism In 167 Nm Deep Ultraviolet Solid State Laser

High average power diode-pumped picosecond(ps)all-solid-state lasers have been found important applications and development prospect in many fields such as industrial micromachining,medical treatment,and scientific research.The combining of high pulse energy and high peak power together makes them useful in many fields.For example,the ps green pulses with several kHz repetition rate have important applications in satellite laser ranging(SLR)and laser ablation of human tissue in medical surgery.Moreover,due to the excellent properties,high average power ps all-solid-state lasers have significant application in laser nonlinear frequency conversion.For achieving the high energy,high power,and high beam quality ps solid-state lasers,we have made an in-deep study on the difficulty and key technology in high average power ps solid-states laser amplication and nonlinear frequency conversion,including passively mode-locked technology with a SESAM,regenerative amplification(RA)technology,Innoslab laser amplification technology,Zigzag slab laser amplification technology,second harmonic generation(SHG)technology.The main achievements:The high energy ps Nd:YVO4 RA at 1342 nm was investigatd for the first time.The combination of 880 nm direct pumping and composite bonded laser crystal was adopted tc reduce the thermal effect and a high average power passively mode-locked 1342nm Nd:YV04 oscillator with a SESAM was produced.After the seed beam from the master oscillator pulse laser was injected into the RA cavity,the RA was obtained operating from 1 to 10 kHz.The maximum pulse energy of 0.243 mJ and the maximum peak power of 5.55 MW were obtained at 1 kHz with the pulse width of 43.8 ps.The laser beam quality factor of M2 was measured to be 1.65 at the full output power.It is for the 167.75 nm DUV laser that generated through cascaded SHG process and applied inangleresolved photoemission spectroscopy.We have researched on the cavity-dumped mode-locked technology,which was the usage of diode-pumped cavity-dumped laser in combination with highly reliable mode-locking technique using a SESAM.It is an alternative method to efficiently generate high pulse energy and requires only a single resonator resulted in operating at kHz and reducing the complexity.To the best of our knowledge,it was the first time reported from picosecond CDML oscillator at 1342 nm.At 10 kHz,an average output power of 0.119 W was achieved,corresponding to a pulse energy of 11.9?J.The dumping rate was about 94%.Meanwhile,the beam quality was nearly diffraction limited with average beam quality factor M2 of 1.49.The pulse width was measured to be 33.4 ps,resulting in the peak power of 356 kW.The CDML lasers are well suited to replace complex regenerative amplifier systems for many applications in physics,bioscience,and material processing.Also,this oscillator laser can be employed as a seed source for the higher energy picosecond amplifier.