Since the early 1990s, guided munitions have allowed the U.S. military to precisely strike targets from afar. Today, in an era of robust electronic warfare and GPS-denial, that capability is no longer assured. DARPA created the Precise Robust Inertial Guidance for Munitions (PRIGM) program to develop inertial sensor technologies that enable positioning, navigation, and timing (PNT) in GPS-denied environments. As part of the work, PRIGM:AIMS is exploring alternative technologies and modalities for inertial sensing, including photonic and MEMS-photonic integration.
Last week, a PRIGM:AIMS performer team led by the University of California, Santa Barbara, published results in Nature Photonics describing new chip-scale Brillouin laser technology that was demonstrated to support an optical gyroscope and a low-phase-noise photonic oscillator.
Integration of these lasers could dramatically reduce the cost and footprint for applications of military interest such as atomic clocks, inertial sensors, other sensor types, and ultrahigh-capacity fiber networking.
Abstract: Brillouin Lasers
Spectrally pure lasers, the heart of precision high-end scientific and commercial applications, are poised to make the leap from the laboratory to integrated circuits. Translating this performance to integrated photonics will dramatically reduce cost and footprint for applications such as ultrahigh capacity fibre and data centre networks, atomic clocks and sensing. Despite the numerous applications, integrated lasers currently suffer from large linewidth. Brillouin lasers, with their unique properties, offer an intriguing solution, yet bringing their performance to integrated platforms has remained elusive. Here, we demonstrate a sub-hertz (~0.7 Hz) fundamental linewidth Brillouin laser in an integrated Si3N4 waveguide platform that translates advantages of non-integrated designs to the chip scale. This silicon-foundry-compatible design supports low loss from 405 to 2,350 nm and can be integrated with other components. Single- and multiple-frequency output operation provides a versatile low phase-noise solution. We highlight this by demonstrating an optical gyroscope and a low-phase-noise photonic oscillator.