Transparent quantum networks will enable rapid scaling and broad geographic accessibility to quantum computation and communication systems. Before such goals can be achieved, suitable optoelectronic components must be developed that are capable of carrying, routing, and heralding quantum information. Key amongst these components are stable, narrow linewidth lasers, commercial options of which are bulky, expensive, and exhibit inferior performance to state-of-the-art in academia. Proposed herein is a narrow linewidth quantum dot laser that leverages an epitaxial active-passive platform that will enable >100Ã reduction in cost, a chip-scale device footprint, and performance matching state-of-the-art. The platform utilizes a vertically offset passive waveguide in the epitaxial material stack that can, through top-down fabrication, be designed to include rings, gratings, phase shifters, and other passive optical technologies. With tailored designs this platform could produce < 150 kHz narrow-linewidth lasers, fast tunable lasers, optical frequency combs, and single photon sources. The designs can be engineered to deliver high power levels suitable for short-reach (<10 km) fully transparent optical networks. Enhancing the platform capabilities, the O-band quantum dot active region possesses unique characteristics making it insensitive to external reflections and able to provide narrower linewidths than could be achieved in a quantum well device on an analogous platform. Together, these individual attributes form a technology uniquely amenable to the needs of a transparent quantum network: stable operation, narrow linewidth, high power, and diverse functionality. In Phase I, a design and simulation feasibility study will be conducted to targeting < 150 kHz linewidth laser at an output power >25 mW using a novel technology platform. Devices will be simulated to optimize the epitaxial layer stack in pursuit of high power and narrow linewidth. This will require independent evaluation of the gain region and all passive cavity elements. Designs will emphasize both performance and manufacturability. Subsequent work in Phases II and III would involve experimental demonstration of the proposed platform including performance meeting the program metrics. Following proof-of-concept, the manufacturing process would be scaled using foundry partners. Laser epi growth and device fabrication would utilize US based manufacturers and be capable of scaling to large volumes. While the benefits of a high-performance narrow linewidth laser are apparent, this platform could also enable other devices to meet the needs of current and future quantum networks and broader applications in communications, sensing, and other areas of optoelectronics.
