Repetition rate tunable microjoule Yb femtosecond fiber laser for applications in ophthalmology

We present an integrated repetition rate tunable Yb-fiber laser system delivering microjoule pulses with compressed pulse duration below 350 fs. The system uses a chirped fiber Bragg grating as fiber stretcher, which is specially designed to match the second and third order dispersion of transmission grating pair compressor with a groove density of 1740 l/mm. 1 μJ pulse in 266 fs and 10 μJ pulse in 325 fs pulse duration are obtained at rep-rate of 2 MHz and 200 kHz, respectively. The pulse rep-rate can be tuned from 200 kHz to 2 MHz while maintaining ⪅350 fs microjoule pulses output. This rep-rate tunable, μJ-level fiber laser source is built for applications in ophthalmology, such as cornea flap cutting and tissue vaporization.