All-fiber low-noise 1.06 μm optical frequency comb generated by a figure-9 laser with chirped fiber Bragg grating

As the applications of optical frequency combs (OFC) continue to diversify, there is a growing demand for compact and low-noise OFCs at 1 μm. Here, we introduce an all-fiber 1.06 μm figure-9 OFC, which can produce dispersion-managed soliton (DMS) with low phase and intensity noise. The figure-9 cavity is formed by cooperating a nonlinear amplified loop mirror with a home-made chirped fiber Bragg grating (CFBG). The unique specifications of the CFBG, including reflectivity and chirp, are tailored to effectively suppress amplified spontaneous emission at 1030 nm and balance the net cavity dispersion. Comparative analysis with a dissipative soliton OFC reveals that our DMS OFC demonstrates superior performance with lower intensity and phase noise. Furthermore, the implementation of a phase-locked loop enables long-term frequency locking, resulting in an exceptional repetition rate fluctuation of 17 μHz over 9 hours. This compact, low-noise 1.06 μm OFC could be a promising light source for applications like dual-comb ranging and spectroscopy.