Compact optical image amplifier pumped by a sub-nanosecond Nd:YAG microlaser

Appl Opt. 2018 Apr 1;57(10):2622-2626. doi: 10.1364/AO.57.002622.

Abstract

A compact sub-nanosecond optical image amplifier is proposed and demonstrated. It is pumped by an actively Q-switched diode-pumped Nd:YAG microlaser in virtue of the optical parametric amplification (OPA) technique and quasi-phase-matching scheme. Experimental results show that the optical image gain reaches 15.4 dB under a pump intensity of 15.3 MW/cm2. The influence of parametric fluorescence noise on the amplified image is obvious above 10 dB gain. The signal-to-noise ratio degradation of the amplifier image characterized by the noise figures is in sheer contrast with theoretical expectations. It shows that the experimental noise figure value reaches 2.2 dB, larger than the theoretical result of 0.7 dB at 15 dB gain.