Travelling-wave 1.57-µm optical parametric oscillator driven by a pulsed multimode Nd3+:YAG laser

The generation properties of an optical parametric oscillator (OPO) with a three-mirror ring resonator have been investigated under conditions of a pulsed pump by multimode radiation from a Nd³⁺:YAG laser. KTP crystals were used as the OPO nonlinear medium. At pump energies up to 100 mJ, decreasing the diameter d of the Nd³⁺:YAG laser beam causes a decrease in OPO radiation divergence and an increase in the generation efficiency at λ = 1.571 μm despite a decrease in the differential efficiency. At d = 2.25 mm and a KTP crystal total length of 40 mm, the efficiency of the pump conversion to the signal-wave pulse reaches 36.5%. Based on the traveling-wave OPO, a compact, highly effective, eye-safe laser source radiating pulses of up to 35 mJ in energy, 11 nsec in duration, and 10 Hz in repetition rate at electrical pump energy of ≤ 8 J is developed. At the 86.5% level of the total pulse energy, the source-beam divergence does not exceed seven diffraction limits. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 4, pp. 516–523, July–August, 2008.     

1. 57μm OPO 人眼安全激光技术的军用前景分析

对1. 57μm 光参量振荡人眼安全激光在人眼安全、全天候工作能力、对战场烟雾的穿透能力等方面的优势进行了分析,介绍了国外近年来几种典型的1. 57μm OPO 人眼安全激光雷达系统的研制情况,提出了大力发展1. 57μm OPO 人眼安全激光技术的建议。     

Intracavity parametric conversion of radiation from a pulsed Nd:YVO<Subscript>4</Subscript> laser with high-power diode pumping

We have achieved intracavity parametric conversion of the radiation from a laser based on Nd:YVO₄ with high-power diode pumping. An LiF^2- crystal was used as the passive Q-switch for the Nd:YVO₄ laser. We have shown that by using an active element in the master laser with a passive region, we can form pulsed laser beams at a wavelength of 1.57 μm with peak power 3.2 kW and repetition rates up to 80 kHz, with beam quality parameter 1.4–1.8. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 1, pp. 5–8, January–February, 2006.