All-Fiber, Wavelength and Repetition-Rate Tunable, Ultrafast Pulse Generation in the 2.0 μm Region Without Mode-Locking

We show 3.0 ps pulses from 1877 nm to 2008 nm at variable repetition rates up to 18 GHz using time-lens compression of a tunable CW laser. The center wavelength is changed by tuning the CW seed laser, and the repetition rate is changed by electronically tuning the drive of the master RF clock. The repetition rate of 18 GHz represents a record speed for pulse generation in this spectral region. This simple all-fiber platform uses standard 1550 nm telecom components, offering a turn-key, flexible, robust alternative to pulse generation in the 2.0 μm region with both wavelength and repetition rate tunability.