Narrow linewidth diode laser self-injection locked to a high-Q microresonator

Laser systems with simultaneously narrow linewidth and high power are crucial in many research areas and applications. We present a novel laser system based on a regular multi-frequency laser diode and high-Q optical whispering gallery mode (WGM) microresonator. The self-injection locking effect is used to narrow the linewidth of the laser diode emission down to 2 kHz without significant reduction in the output optical power. The compact prototype device based on the proposed optical scheme is manufactured.