SBIR-STTR Award

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. Atomic clocks represent the most precise and accurate instruments developed by scientists to date, offering measurement instabilities below 1x10-16 in a second. 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 (< 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. Anticipated

Benefits:
The ultra-narrow linewidth laser will be suitable for NASA’s next generation chip-scale optical atomic clocks (timing, navigation, and magnetometry), ultra-low phase-noise microwave generation for RADAR detection of slow-moving objects with low RADAR cross-sections (timing, navigation, and sensing), and high precision remote sensing technologies such as dual comb spectroscopy (atmospheric sensing, molecular species identification). Department of Defense and commercial applications include optical atomic clocks, time and frequency transfer (of precision timing signals), ultra-low phase-noise microwave generation, dual comb spectroscopy, precision optical metrology, and astronomical spectrograph calibration.

Vescent Photonics, LLC (Vescent) in collaboration with the Massachusetts Institute of Technology Lincoln Laboratory (MIT-LL) proposes to develop a compact ultra-narrow linewidth laser based on photonic integrated chip (PIC) technology for next-generation fieldable quantum sensor applications including optical atomic clocks, two-way time transfer, and precision inertial force and gravity sensing. Atomic clocks represent the most precise and accurate instruments developed by scientists to date and enable applications including the measurement of weak gravitational fields in near-zero gravity as well as accurate positioning, navigation, and timing (PNT) onboard a spacecraft. However, high-performance optical atomic clocks, including Sr+ trapped-ion clocks, currently only exist in laboratory settings due to constraints on the size, weight, power, and cost (SWaP-C) and environmental susceptibility of critical technology subsystems. One of the key subsystems so far hindering the transition of these high-performance optical clocks outside the laboratory is the ultra-narrow-linewidth (< 100 Hz) laser required to interrogate the atoms. The solution proposed here for the development of an ultra-narrow linewidth laser is an extension to the initial demonstrations by Dr. William Loh at MIT-LL with fiber-based stimulated Brillouin scattering (SBS) lasers which have been demonstrated in an operating Sr+ trapped-ion clock, resulting in an ADEV of 3.9E-14/(Tau)^(0.5). Using these fiber-based results as a baseline, recent measurements conducted by the MIT-LL team have shown an evolution toward PIC-based waveguide cavities that can support ultranarrow-linewidth lasers via SBS. The effort proposed here seeks to integrate necessary chip-scale components to move towards a design where the entire ultra-narrow-linewidth laser system is contained on a chip-scale device. Anticipated

Benefits:
This proposal directly addresses two of NASA’s research topic areas: S1.10 Atomic Quantum Sensors and Clocks and T8.07 Photonic Integrated Circuits. The laser hardware developed under this effort will be suitable for optical atomic clocks, atomic interferometers, and any applications requiring small, low-power lasers for remote sensing including the following missions: Moon to Mars, CLPS, Flight OPPS, and ISS. Vescent has identified several applications that would benefit from a low SWaP ultranarrow linewidth laser and include: optical atomic clocks, time and frequency transfer, ultralow microwave phase noise generation, dual comb and precision spectroscopy, precision inertial force and gravity sensing, and lidar.