Linewidth Suppression of Light-wave and Photo-generated Microwave Based on Optoelectronic Feedback Integrated Laser

A scheme to suppression the linewidth of the integrated laser mode and the opto-generated microwave based on opto-electronic feedback is proposed and experimentally demonstrated. The front section laser and the rear section laser are mutual injected and integrated on the same chip which is easily controlled and with sample structure. The linewidth of the free-running front laser mode is 12MHz, the linewidth of the directly opto-generated microwave with 19.95GHz is 8MHz when the integrated laser is at two-modes state (nonlinear state) under mutual injection. After employing the opto-electronic feedback loop, the coherence of the front and rear lasers is improved. The linewidth of the front laser reduced to 2MHz and the linewidth of the opto-generated microwave is suppressed to 1kHz which promotes over 3 orders of magnitude.