Phase Noise Reduction of a Quantum Dash Mode-Locked Laser in a Millimeter-Wave Coupled Opto-Electronic Oscillator

Quantum dash active region Fabry-Perot lasers emitting at 1570 nm without an absorbing section have been evaluated as an optical source for microwave signal generation. These devices self-pulsate at 39.9 GHz with a mode-beating spectral linewidth as narrow as 10 kHz. Integration of these devices into an Opto-Electronic Oscillator has been performed, demonstrating a phase noise reduction of more than 15 dB in the low-frequency range. Moreover, the measured phase noise spectrum is well explained by a rate equation model taking into account the feedback loop.