Tunable mode-locked erbium-doped fiber laser based on a digital micro-mirror device

Full C-band wavelength-tunable, 250 MHz repetition rate mode-locked polarization-maintaining fiber laser

We demonstrate a full C-band wavelength-tunable mode-locked fiber laser with a repetition rate of 250 MHz, representing the highest repetition rate for C-band tunable mode-locked lasers thus far to the best of our knowledge. The polarization-maintaining fiber-based Fabry-Perot cavity enables a fundamental repetition rate of 250 MHz with a semiconductor saturable absorber mirror as a mode-locker. We observed a stable and single soliton mode-locking state with wide tunability of the center wavelength from 1505 to 1561 nm by adjusting the incident angle of a bandpass filter inside the cavity. The wavelength-tunable high-repetition-rate mode-locked laser covering the full C-band is expected to be a compelling source for many frequency-comb-based applications, including high-precision optical metrology, broadband absorption spectroscopy, and broadband optical frequency synthesizers.

Linear-cavity Er-doped fiber mode-locked laser with large wavelength tunability

A linear-type wavelength-tunable all-polarization-maintaining fiber mode-locked laser is proposed for the first time, to our knowledge, and is implemented with an Er-doped fiber and polarization-maintaining fiber components. The tuning range of the center wavelength is from 1533.7 nm to 1565.6 nm. The linear-type configuration makes the proposed laser simpler and more compact, allowing it to achieve the highest repetition rate of 126.5 MHz among C-band wavelength-tunable mode-locked lasers due to its short cavity length. Also, its polarization-maintaining fiber components provide reliable operating robustness. The significant wavelength tunability and high repetition rate of the proposed laser can be expected to make it an attractive resource for various applications, including optical communications, broadband spectroscopic LIDAR, and high-precision ranging.