Abstract
We report an active Q-switching with different coded schemes generated in the high power diode end pumped Nd:YVO4laser (DEPSS)using two different techniques of special combination of optical choppers and acousto-optic modulator (AOM) at higher repetition rates of 100 kHz for the first time to the best of our knowledge in any practical laser target designation (LTD) systems.This paper presents experimental studies on a high-efficiency, high power diode laser module of 6W at 808nm end-pumped 3×3×10mm Nd: YVO4 laser with high efficient water cooling system. An optical slope efficiency to be around 76%, the final conversion efficiency to be 63% and an output laser power of over 3.8W at 1064nm laser was obtained with a high beam quality factor of M2 <1. A single Q-switched pulse with high peak power of 1.1 kW and pulse width of 40-ns at FWHM is produced at input pumping power of 3W using optical chopper. The pulse-to-pulse stability was measured and improved to be ~ 96.7 % with frequency near 20 kHz.The highest peak power of 95.4 kW with lowest pulse repetition frequency of 221.6 Hz and pulse width of 46 ns at FWHM with the pulse-to-pulse stability of ~ 95 % was measured at certain regime of operation. Special modulation and coding of high stable, high peak power Nd: YVO4 laser pulses at 1064nm using the combination of different optical chopper blades were achieved. A high peak power is increased to be more than 4.84 kW with shortest pulse width of 25 ns at FWHM have been obtained using an acousto-optic modulator (AOM) as an active Q-switched. The pulse-to-pulse stability was measured and improved to be ~ 97 % at high repetition rate ranges from 10 kHz to 100 kHz. The performance and availability for the DEPSS laser cavity with two different techniques for producing high frequencies and an output controlled laser coding schemes which can be used in military equipment as laser target designation systems and laser range finders were investigated.