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arXiv · 2604.19058

Brillouin-Enhanced Photonic Stepped-Frequency Radar

Ziqian Zhang·Ryan L. Russell·Choon Kong Lai·Benjamin J. Eggleton
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Abstract

Photonic stepped-frequency (SF) radar offers high range resolution and only requires low-speed driving electronics, but existing architectures face challenges in achieving low phase noise and uniform frequency steps simultaneously. Here, we demonstrate a photonic SF radar system that exploits dual Brillouin lasers in a shared fiber cavity to simultaneously suppress phase noise and ensure uniform frequency stepping. Phase noise is reduced through Brillouin optomechanical suppression and common-mode noise rejection upon photomixing. Frequency-step uniformity is enforced via lasing at a series of uniformly spaced cavity resonances. The system generates an X-band SF waveform spanning 1.31 GHz, achieving >23 dB of phase-noise improvement at a 100 kHz offset relative to a low-cost driving voltage-controlled oscillator. The demonstrated system reduces the dependence of the output waveform quality on noise in the driving electronics, offering a path towards high-performance radar sensing.

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Ziqian Zhang, Ryan L. Russell, Choon Kong Lai, Benjamin J. Eggleton. 2026-04-21. Brillouin-Enhanced Photonic Stepped-Frequency Radar. https://arxiv.org/abs/2604.19058

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