Extended Lifetime, Narrow Linewidth 780nm Lasers on Integrated Platform for Chip-Scale Quantum Technologies

The Navy has the need for narrow linewidth, tunable NIR laser diodes in the range of 770-852.5 nm with extended operational lifetime. Light Integration Technologies (LIT) and Freedom Photonics are collaborating to develop a high-power and low-linewidth laser platform targeting quantum sensing / timing applications. High-performance quantum sensing and timing applications often require ultra-stable and long-lifetime lasers that can address atomic resonances in the 700 nm to 800 nm range for Rb and 800 nm to 852 nm range for Cs, however these lasers either have too large size, weight, power consumption (SWaP) or are compact, lower-power, and lack adequate lifetime for mission critical systems. Thus, there is a need for improved performance lasers with extended lifetime for quantum sensing applications and is the primary focus of this project. The following is statement of work (SoW) to develop and package the reliable, extended lifetime, sub-megahertz linewidth 780nm wavelength lasers on integrated platform for chip-scale quantum technologies.The photonic platform is based on high-power and high-efficiency III-V gain components from both Light Integration Technologies and Freedom Photonics, designed for integration with Light Integration Technologies’ ultra-low loss SiN waveguides and filters to formulate extended lifetime lasers meeting the required specifications. Our approach is twofold for risk mitigation. In one approach, Light Integration Technologies will develop high-power, narrow linewidth DFB lasers with Al-free active and waveguide regions for extended lifetime and reliability. The DFB epitaxial material will be designed for heterogeneous integration by both flip-chip bonding and micro-transfer printing schemes on their ultra-low loss SiN PIC platform, however, in this program the device structures and fabrication sequence will be developed for mounting chip-on-carrier and standard packaging to meet the required performance specifications. In another approach, Freedom Photonics will integrate their 7xx nm wavelength, high-power III-V gain material via photonic wirebonds with Light Integration Technologies’ ultra-low loss SiN waveguides and filters to formulate external cavity lasers (ECL). This approach allows for a simplified epitaxial structure and fabrication process, resulting in extended lifetime light sources for quantum sensing and timing, while providing comparable SWaP to typical DFB/DBR chip solutions. The technical specifications for the resulting laser prototypes – to be achieved by the end of the combined Base and Option program – are captured in the table below. The objective of the Phase II Base period is to demonstrate lasers which meet these specifications. The objective of the Phase II Option are to have fully packaged prototypes which meet these specifications.