Abstract

Frequency combs with large line spacing have many applications and are under intense research. Methods for generating such combs either start with initial frequency spaced lasers (like combined single-frequency lasers, phase- and amplitude modulated lasers or mode-locked-laser) or employ nonlinear effects to start or extend its spectral bandwidth in fibers or micro cavities [1-3]. Here we demonstrate the generation of a frequency comb of several nm widths with arbitrary frequency spacing from ~50 GHz to 500 GHz by four-wave-mixing (FWM) of two external cavity lasers (EDCL) combined amplified in a high power large-mode area fiber amplifier. The power levels demonstrated are in the range of several 100 W to 4 kW. We also demonstrate that in the temporal picture, pulses of multiple kW peak power can be generated by compressing the output beam.

© 2017 IEEE