Study On The Output Performances Of The Ho:YAG/YVO₄ Raman Laser

Stimulated Raman scattering?SRS?is a very important method of generating new wavelength laser.The generation of wavelength based on SRS is determined by the fundamental laser and the value of Raman frequency shift of the Raman crystal.All solid state Q-switched Raman laser based on SRS effect have many attractive features,such as beam clean-up,high conversion efficiency,and pulse compression,etc.So it has become a very important research issue in the world.2?m laser is in atmospheric window,and eye-safe,and it has been widely used in traffic detection,medical services,aerospace,and so on.At present,the study of solid Raman lasers is mainly focused on 1?m band,but it is rarely reported in 2?m waveband.So the study on2?m solid state Raman laser in this thesis is very meaningful.First,we establish the rate equations of actively Q-switched Ho:YAG/YVO₄ Raman laser.Based on the rate equations,the output performances?pulse width,peak power,pulse energy,and average output power,etc.?of the Raman laser are numerical simulated,which vary with the system parameters?pump power,cavity length,the output mirror transmittance,etc.?.Then,a actively Q-switched Ho:YAG/YVO₄ intracavity Raman laser is realized in experiment.At last,the average output power,pulse width and single pulse energy of Raman laser have been measured,and we optimize the parameters of the resonator.The wavelength of Raman laser is 2518nm,and the central wavelength of the fundamental laser is 2122nm,which corresponding to a Raman frequency shift of 741cm^-1.When the length of resonator length is 150mm and the curvature of output mirror is 200mm,a maximum average output power of 265mW is obtained at the repetition rate of 1kHz.The narrowest pulse width is 10.2ns.The maximum optical-to-optical conversion efficiency and slope efficiency is 3.7%and 14.4%respectively.