QCW LD Pumped Electro-optic Q-switched Nd:YAG Laser

Quasi-continuous LD pumped electro-optic Q-switched lasers have many advantages such as high efficiency,high peak power,narrow pulse width,and good energy stability.It has been widely used in ranging,guidance,Industrial processing and medical applications.Based on the research status of LD pumped electro-optic Q-switched laser at home and abroad,this paper introduced the related theories of LD pumped Q-switched laser and amplification technology,and analyzed the factors that affect the amplification energy extraction.According to the characteristics of LD and the beam shaping method,the LD side pump module was designed and the pump light distribution inside the crystal pumped by the three-dimensional side of the LD array was calculated with ZEMAX software.A quasi-continuous LD pumped electro-optic Q-switched laser was built using a parallel planar asymmetric resonant cavity structure.The maximum energy of a single pulse was 61.7mJ,the pulse width was 29.87 ns,and the peak power was 2.07 MW.Pulse energy had been monitored for 4 hours,energy instability was less than ± 0.8%.The passive Q-switch crystal was putted in the resonant cavity to obtain a maximum single pulse energy of 28.39 mJ,pulse width of 28.4ns,and the symmetry of the pulse waveform was obviously improved.Using the MOPA structure,a Xenon lamp pumped Nd:YAG was used to amplify the energy of the electro-optic Q-switch pulse.When the output energy of the local oscillator stage was 61.7mJ,the maximum single pulse energy was 636.7mJ,and the magnification reached 10.32.The optical field distribution of the output beam was shaped using the beam shaping device.When the output energy of the local oscillator stage was 55.1mJ,the maximum single pulse energy was 612 mJ.