An efficient low-noise single-frequency 1033 nm Yb3+-doped MOPA phosphate fiber laser system

Abstract

An efficient low-noise, single-frequency 1033 nm master oscillator power amplifier (MOPA) Yb3+-doped phosphate fiber (YPF) laser system is demonstrated. A maximal output power of 612 mW with a laser linewidth of <1.2 kHz is obtained from a 3.7 cm long YPF. By suppressing the intensity noise of the short-cavity phosphate fiber oscillator with a semiconductor optical amplifier, a measured signal-to-noise ratio from the MOPA system of >65 dB and relative intensity noise (RIN) of <−120 dB Hz−1 at the relaxation oscillation frequency are achieved. Moreover, an RIN of <−152 dB Hz−1 is achieved for frequencies above 15.0 MHz, which approaches the shot noise limit. This laser system has applications in the fields of optical frequency standards and beam combining.