Abstract:
Femtosecond laser sources operating at around 2 μm spectral range support a plethora of applications, especially in high-resolution molecule spectroscopy, synthesis of mid-infrared optical frequency combs, and broadband mid-infrared sources. Cr:ZnS/ZnSe with broad emission bands is an ideal material to support femtosecond pulse generation at around 2 μm spectral range. Femtosecond mode-locked lasers with all-normal dispersion have recently attracted great attention due to their short pulse duration and large output pulse peak power. An operation of femtosecond Kerr-lens mode-locked laser was demonstrated in Cr: ZnS with all-normal dispersion. The laser system delivered stable mode-locked pulses with pump power of 5.1 W, spectral range from 2.0 to 2.7 μm, average power of 660 mW, duration of 37 fs. It is the first time to realize the operation of femtosecond mode-locked solid laser with all-normal dispersion in Cr: ZnS, which have potential applications in high-resolution molecule spectroscopy and generation of broadband mid-infrared sources.