Ultra-narrow Linewidth Lasers for Deployed Quantum Timing Applications

Vescent Photonics, LLC in collaboration with the Massachusetts Institute of Technology Lincoln Laboratory proposes to develop a compact, chip-scale ultra-narrow linewidth laser for next-generation fieldable quantum sensor applications including optical atomic clocks, two-way time transfer, and precision inertial force and gravity sensing.nbsp; Atomic clocks represent the most precise and accurate instruments developed by scientists to date, offering measurement instabilities below 1x10-16 in a second.nbsp; This level of accuracy enables the application of optical atomic clocks to a whole host of precision sensors, including the measurement of weak gravitational fields in near-zero gravity as well as accurate positioning, navigation, and timing onboard a spacecraft. However, high performance optical atomic clocks currently only exist in laboratory settings due to requirements of an ultra-narrow-linewidth (lt; 10 Hz) interrogation laser used as an optical flywheel for the atomic clock transition. The solution presented here for the development of an ultra-narrow linewidth laser is an extension to the initial investigations of Dr. William Loh at MIT-LL with chip-scale stimulated Brillouin scattering (SBS) cavities. Recent measurements conducted by the MIT-LL team have shown that chip-based photonic waveguide cavities can support ultranarrow-linewidth lasers; this effort seeks to increase the integration of necessary chip-scale components to move towards a design where the entire laser system is contained on a chip-scale device. This effort will focus on a design for chip-based SBS laser cavity with integrated frequency doubling for direct laser light generation at 674 nm for a 88Sr+ optical atomic clock. Packaging will also be designed to integrate easily with the near-infrared pump laser at 1348 nm.