A Self-Synchronized Optoelectronic Oscillator Based on an RTD Photodetector and a Laser Diode

We propose and demonstrate a simple and stable low-phase noise optoelectronic oscillator (OEO) that uses a laser diode, an optical fiber delay line, and a resonant tunneling diode (RTD) free-running oscillator that is monolithic integrated with a waveguide photodetector. The RTD-OEO exhibits single-side band phase noise power below - 100 dBc/Hz with more than 30-dB noise suppression at 10 kHz from the center free-running frequency for fiber loop lengths around 1.2 km. The RTD-OEO can be controlled either by the injected optical power or the fiber delay line and its power consumption is below 0.55 W. The RTD-OEO stability is achieved without using other high-speed optical/optoelectronic components and amplification.