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.
© 2014 Optical Society of America
Original Manuscript: November 11, 2013
Revised Manuscript: January 31, 2014
Manuscript Accepted: February 13, 2014
Published: March 13, 2014
Stefan Preussler, Norman Wenzel, and Thomas Schneider, "Flat, rectangular frequency comb generation with tunable bandwidth and frequency spacing," Opt. Lett. 39, 1637-1640 (2014)