Amplitude noise of subharmonically hybrid mode-locked pulses generated from a monolithic semiconductor laser

Broad-band amplitude noise (100 MHz to 20 GHz) of 40 GHz pulses generated by a subharmonically hybrid mode-locked (SHML) monolithic semiconductor laser is investigated. Experiments show that the amplitude noise can only be suppressed at some certain subharmonic numbers, while the phase noise can be suppressed by subharmonic hybrid mode-locking under many subharmonic numbers.