Integrated chalcogenide optical amplifiers and parametric oscillators for the mid- and long-wavelength infrared

Nontechnical Description: This project aims to develop a chip-scale, pulsed light source for the long-wavelength infrared “chemical fingerprint” region of the spectrum, where the distinct vibrational signatures of many molecules make possible highly sensitive and selective detection. Light sources that reach these wavelengths are important for a wide range of applications, including industrial process control, medical diagnostics such as breath analysis, environmental and atmospheric monitoring, secure free-space communications, and precision navigation and timing. Despite this broad demand, conventional laser technology has struggled to reach the long-wavelength infrared region due to a lack of suitable materials. This project addresses that gap by combining nonlinear optical materials with integrated photonics, a technology that places optical circuits directly on a computer chip using fabrication techniques compatible with standard electronics manufacturing. A compact, chip-scale light source of this kind would represent a significant advance for the field of photonics, enabling low-cost, portable, and scalable instruments in place of the bulky, expensive laboratory equipment such sources currently require. The resulting technology would provide broad societal benefits, including improved industrial process monitoring, earlier and more accessible medical diagnostics, and more sensitive detection of trace gases relevant to environmental and public health, thereby helping to secure U.S. competitiveness and improve quality of life. The project also provides valuable interdisciplinary training opportunities, giving undergraduate and graduate students hands-on research experience that spans materials science, optics, and photonic device engineering. This experience blends coursework with laboratory work and strengthens the pipeline of a diverse science and engineering workforce prepared to contribute to the growing photonics industry. Technical Description: The technical goal of this project is to demonstrate a chip-scale optical parametric oscillator (OPO) capable of efficient, tunable generation of light in the mid- and long-wavelength infrared. Optical parametric oscillators convert light from a pump laser into new wavelengths through nonlinear optical interactions, and they have been implemented in bulk, table-top setups for over five decades. Translating this approach to a chip-scale platform, however, has been limited by the difficulty of finding a material that combines high second-order nonlinearity with low optical loss and broadband transparency at long wavelengths, while also being compatible with on-chip fabrication. This project addresses that challenge using chalcogenide glasses, a class of materials that are transparent to wavelengths up to 20 microns and have nonlinearities two orders of magnitude larger than fused silica, the material most commonly used in integrated photonics. By combining these materials with an on-chip amplifier in a homogeneously integrated platform, the project aims to establish a new class of chip-scale light source spanning the mid- and long-wavelength infrared. The resulting technology is expected to have significant impact on electrical and mechanical engineering, physics, and astronomy, and will enable new sensing applications in spectroscopy, medicine, environmental monitoring, and free-space communications. These research goals are closely integrated with the project's education and outreach plans. Interdisciplinary research opportunities for undergraduate and graduate students, will blend fundamental research with education both in the laboratory and the classroom, while also supporting broader efforts to recruit and retain students from diverse backgrounds in engineering and the physical sciences. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.