Tunable frequency combs for photonic applications

A high quality frequency comb with widely spaced and tunable spacing is generated via an injection locked harmonically mode-locked laser. This is achieved via adjustment of the mode-locking rate in steps of the cavity fundamental frequency. An optical SNR of 36 dB and over 7 nm of optical bandwidth is achieved. Power spectral density of the relative phase noise is shown and a marked improvement in the integrated (1Hz to 100 MHz) timing jitter from 32 fs to 12.9 fs is demonstrated, making the source ideal for frequency comb applications such as multi-heterodyne spectroscopy and novel linear modulator technology which require comb spacing flexibility.