Frequency multiplication in actively mode-locked semiconductor lasers

Abstract

We report a method that enables an external-cavity semiconductor laser to be actively mode locked at multiples of the radio frequency (rf) drive frequency. The key to this method is the choice of the relationship between the external cavity resonance frequency and the rf drive frequency. The repetition rate of the output pulses is the lowest common multiple of the external cavity resonance frequency and the rf modulation frequency. The method has been demonstrated in a laser with a cavity resonance frequency of 1 GHz; 17 GHz pulse streams were generated using rf drive frequencies of 8.49 and 5.67 GHz.