Chip-scale high-performance photonic microwave oscillator

TL;DR

This paper presents a miniaturized, chip-scale photonic microwave oscillator with ultra-low phase noise, achieved through integrated optical frequency division using dual lasers and a novel lithium niobate modulator.

Contribution

The work introduces the first integrated electro-optical frequency division microwave oscillator on a chip with record low phase noise performance.

Findings

Achieved phase noise of -129 dBc/Hz at 10 kHz offset for 37.7 GHz

Used dual laser sources with silicon nitride resonator for high stability

Implemented a novel thin-film lithium niobate phase modulator for optical-to-microwave division

Abstract

Optical frequency division based on bulk or fiber optics provides unprecedented spectral purity for microwave oscillators. To extend the applications of this approach, the big challenges are to develop miniaturized optical frequency division oscillators without trading off phase noise performance. In this paper, we report a chip-scale electro-optical frequency division microwave oscillator with ultra-low phase noise performance. Dual laser sources are co-self-injection-locked to a single silicon nitride spiral resonator to provide a record high-stability, fully on-chip optical reference. An integrated electro-optical frequency comb based on a novel thin-film lithium niobate phase modulator chip is incorporated for the first time to perform optical-to-microwave frequency division. The resulting chip-scale photonic microwave oscillator achieves a phase noise level of -129 dBc/Hz at 10 kHz offset for 37.7 GHz carrier. The results represent a major advance in high performance, integrated photonic microwave oscillators for applications including signal processing, radar, timing, and coherent communications.