600 mW optical output power at 488 nm using a high power hybrid laser diode system and a PPMgLN bulk crystal

摘要

Frequency conversion of near infrared diode lasers provides an efficient method to generate laser radiation in the visible spectral range. There are several requirements for efficient frequency doubling like singlemode emission and good beamquality, which can be fulfilled by light sources based on master oscillator power amplifier (MOPA). This contribution reports on the generation of 600 mW output power at 488 nm by single pass frequency doubling. An InGaAs distributed feedback (DFB) laser was used as MO and an InGaAs tapered amplifier as PA in a MOPA diode laser system. A maximum output power of 4 W at 976 nm was achieved in continuous wave operation mode, at a heatsink temperature of about 0℃ with this pump source. For frequency conversion a 30 mm long PPMgLN bulk crystal held at 65℃, was used in a simple single-pass configuration. A maximum conversion efficiency of 15% and an overall wall-plug efficiency of 4% were achieved.