Low-noise operation (−140 dB/Hz) in close-coupled Nd:YVO_4 second-harmonic lasers pumped by single-mode laser diodes

Abstract

Very-low-noise operation (as low as -140 dB/Hz) of close-coupled Nd:YVO(4) lasers is reported. This low noise level has been attained by controlling the spectra of the pumping laser diodes into the single longitudinal mode by suppressing mode hopping. The small-packaged second-harmonic laser (Φ12 × 16 mm) showed highly stabilized 530 nm/6 mW operations with a relative intensity noise of -140 dB/Hz.