Low noise operation of an all polarization-maintaining figure-9 Er:fiber laser with near-zero cavity dispersion

Abstract

We demonstrate the low noise operation of a figure-9 1.5-μm Er:fiber laser constructed by all polarization-maintaining (PM) fiber and fiber components. Starting from the original rate equations and nonlinear Schrödinger equation, the cavity roundtrip evolution toward stable mode locking state is present. The radio frequency spectrum shows a 94.6-MHz fundamental repetition rate with up to 100 dB high signal-to-noise ratio. The net dispersion is tailored to near zero by incorporating and optimizing the length of PM dispersion-compensating fiber in the cavity. As a result, an integrated root-mean-square relative intensity noise of 0.0026 % [1 Hz, 1 MHz] and 10.8-fs timing jitter [100 Hz, 1 MHz] at the fundamental repetition rate are measured. We also lock the fundamental repetition frequency to a stable radio frequency reference and an in-loop relative stability of 2.1 × 10−12 at 1-s gate time is obtained.