Easy wavelength-tunable passive mode-locked fiber laser through a Lyot filter with a SESAM

In this work, we present an easy wavelength-tunable passive mode-locked fiber laser with a semiconductor saturable absorber mirror as a mode-locker. The cavity includes a Lyot filter as a wide wavelength-tunable filter that can be tuned by simply increasing the retardance of a variable wave retarder. The Lyot filter consists of the variable wave retarder and highly birefringent fiber inserted between two li-near polarizers oriented at the same angle. The highly birefringent fiber has $8.196$ cm length and li-near birefringence $∆n=4.805{x10}^{-4}$ which provides a 61 nm period. Continuous mode-locking was experimentally achieved from 1561.9 to 1546.1 nm by simply increasing the retardance from $0.0778\pi$ to $0.4778\pi$ rad delivering sub-ps pulses width at 10.57 MHz repetition rate.