Low Phase Noise Direct-Modulation Optoelectronic Oscillator

A direct-modulation OEO (DM-OEO) generating stable 10 GHz and 20 GHz signals is presented. A single loop and a dual loop approach are implemented and compared. We show an output signal of 15 dBm RF power, and a phase noise as low as -135 dBc/Hz at 10 kHz offset from the 10 GHz carrier. The 20 GHz second harmonic exhibits a noise level of -127 dBc/Hz at 10 kHz. A high spur level reduction is also obtained in the dual loop architecture.

Automated summary

A direct-modulation OEO capable of generating stable 10 GHz and 20 GHz signals was presented, utilizing both single and dual loop approaches. The output signal exhibited high RF power and low phase noise, with a reduction in spurious levels in the dual loop architecture.