Robust low-noise 795-nm single-frequency fiber laser with continuous frequency tuning

Abstract

This study presents a highly efficient and low-noise all-fiber single-frequency (SF) 795-nm laser system realized using a simple and robust single-pass frequency-doubling configuration. The foundation of the system is a 1590-nm erbium-doped fiber amplifier operating in a master oscillator power amplifier configuration seeded by a distributed feedback semiconductor laser at 1590.52 nm. The main amplifier exhibits an exceptional amplification efficiency of 30.5 %. By utilizing a periodically poled lithium niobate waveguide, the 795-nm laser is frequency-doubled with an output power reaching 2.3 W, corresponding to an optical efficiency of 44 % of the fundamental laser. Crucial to its application in precision measurements and quantum technologies, the SF 795-nm laser exhibits a relative intensity noise close to −150 dBc/Hz in the frequency range of 0.1 to 10 MHz. Additionally, a continuous frequency-tuning range of 11.7 GHz is achieved by modulating the current with a 2.5-mA 1-Hz triangular wave. Notably, this is the first report on an all-fiber SF 795-nm laser system.