Graphene mode-locked Cr:ZnS chirped-pulse oscillator

Abstract

We report the first to our knowledge high-energy graphene mode-locked solid-state laser operating in the positive dispersion regime. Pulses with 15.5 nJ energy and 42 nm spectral bandwidth with 0.87 ps duration were obtained at 2.4 μm wavelength. The output can be compressed down to 189 fs. The graphene absorber damage threshold was established at fluence approaching 1 mJ/cm².