L-band short cavity fiber lasers based on home-made highly Er3+-doped silica fiber

However, the L-band lies at the edge of emission spectrum of Er3+-doped f iber and presents low gain compared to C-band, making the realization of high-performance L-band short cavity lasers challenging.

To address this, this paper systematically investigates L-band short cavity lasers using a home-made, highly Er3+-doped silica fiber. Firstly, a distributed Bragg reflector (DBR) single-frequency laser cavity was constructed using a 3 cm segment of this fiber, achieving single-frequency laser output at 1590 nm with an output power of 10.5 mWand a linewidth of 6.06 kHz. Subsequently, a semiconductor saturable absorber mirror (SESAM) high-repetition-rate passively mode-locked laser cavity was successfully demonstrated based on an 8.4 cm segment of the same gain fiber, yielding stable mode-locked output with a repetition rate of 1.24 GHz, a center wavelength of 1584 nm, and a pulse width of 566 fs.