Flat, rectangular frequency comb generation with tunable bandwidth and frequency spacing

Abstract

The generation of flat, rectangular frequency combs with tunable frequency spacing and bandwidth is demonstrated. Therefore, several lines or sidebands are extracted out of an existing frequency comb, for example a femtosecond fiber laser. Subsequently, these lines are processed via two Mach-Zehnder modulators in order to generate a flat frequency comb with tunable frequency spacing. Optical frequency combs with various spacing and a maximum bandwidth of 260 GHz are generated. However, much higher bandwidth can be reached easily. The overall flatness of the generated combs is within 0.6 dB.