Description: Optical atomic clocks using lasers in the visible or ultraviolet instead of microwave to excite the atoms can provide an evaluate accuracy of 10-18. However, there remains a large gap between the highest performing cold-atom and lattice based optical clocks and the SWaP required to support many technologies needed for NASA missions today. There is a great demand for space-qualified lasers for corresponding clock and cooling transitions. NP Photonics proposes to develop compact, robust, and reliable single-frequency blue lasers that will be developed using our unique highly doped short-length fiber laser technology and can be used for spaceborne optical atomic clocks. In this Phase I program, we will demonstrate the feasibility of the proposed laser sources by developing a diode-pumped single-frequency fiber laser oscillator and power amplifiers and second harmonic generation lasers at the wavelengths of interest. Space-qualified laser sources will be developed and delivered in Phase II.

Benefits: The proposed space-qualified single-frequency laser sources can be used for spaceborne optical atomic clocks that can be used for gravitational wave measurement, deep-space navigation, dark matter and dark energy searches. The single-frequency fiber laser sources at near-infrared can also be used for fundamental physics tests, time and frequency metrology, and water Lidar. The proposed blue laser sources can be broadly used for laser cooling and trapping, optical data storage, underwater communication, submarine imaging and sensing, full color display technology, biomedical applications, undersea oil exploration, and oceanographic Lidar. In addition to ultra-stable narrow-linewidth laser sources for nonlinear wavelength converters, the single-frequency fiber lasers at near infrared can also be used as low-noise, high-brightness pump sources for Yb lasers and remote sensing.