The successful pursuit of this research could lead to the first widely-tunable, integrated synthesized optical sources, which would be much more stable, and have smaller size, weight and power requirements than components currently available. The combination of photonic and electronic integration will produce a chip-scale tunable sources that do not require accurate temperature control or high input power to operate. The project's GOALI partner, Freedom Photonics LLC., intends to commercialize some version of the proposed device that may impact the optical components marketplace. The new technology will be developed within the NSF-NNIN facility and the new fabrication processes will be made to students and outside users. The PIs have a strong commitment to involving high school, and undergraduate students in research activities, including summer internships, and students of under-represented groups in STEM learning programs.
The proposed research aims to develop a highly-integrated widely-tunable optical frequency synthesizer (OFS) with sub-Hz-level accuracy. The integrated OFS is based on a monolithic, 4-section, widely-tunable laser offset-locked to any one of the lines of a frequency comb. By employing a combination of photonic and electronic integration, sub-Hz-level accuracy can be obtained with an integrated optical phase-locked loop (OPLL) technology. All of the photonics, except for the external reference laser, the photodiodes, and the comb generator, will be integrated on a single InP photonic IC . The tunable laser's output can be tuned across the entire comb by tuning the laser between the comb lines with the RF offset source, and alternately selecting different comb lines. With this approach sub-Hz-level relative frequency accuracy, as well as sub-kHz linewidth, should be possible. If successful, the proposed work would have a transformative impact on the design of optical systems for a series of new optical technologies.
