CAREER: GaSb-based Photonic Integrated Circuits for Short- and Mid-Wave Infrared Applications

Photonic integrated circuits (PICs) based on a semiconductor made of antimony and gallium (often referred to as “antimonide”) with monolithically-integrated active and passive components that operate in the extended short- and mid-wave infrared wavelength regime are currently of significant research interest due to a wide range of emerging applications, including chemical sensing, industrial process control, and non-invasive medical diagnostics. This wavelength regime of the electromagnetic spectrum is important because it contains a number of spectral features such as strong overtones and combination molecular absorption bands in gas- and liquid-phase molecules for sensing applications.

This eye-safe spectral regime also has an atmospheric transmission window, which makes it suitable for LiDAR/remote sensing applications. This Faculty Early Career Development (CAREER) project will develop the first non-telecom photonic IC platform based on the antimonide material system. The scientific insights and technological advances stemming from the research will also broadly impact the field of photonics by enabling operation in this underdeveloped spectral region.

Since the research topic will cross different disciplines of science and engineering, such as optics, materials science, electrical engineering, physics, and chemistry, it offers a range of potential, hands-on learning activities that will engage students of varying backgrounds. In addition to high impact research advancement, this project will support interdisciplinary education activities in nanoscience and nanotechnology.

The educational and outreach components are aimed at promoting interests in science, technology, engineering, and mathematics (STEM) disciplines and propagating educational opportunities by exposing K-12, undergraduate and graduate students to advancements in optics and photonics.

The overarching goals of this project are to advance intellectual understanding of the low-bandgap antimonide material system for the development and demonstration of a photonic integrated circuits (PICs) technology platform in the extended short- and mid-wave infrared (S-MWIR) spectral band and to expand educational opportunities related to infrared materials science and device technology. The primary research goals of the proposed project are to (1) develop the first non-telecom photonic integrated circuits platform, (2) realize novel single-chip–based widely tunable lasers and other PIC components with an emission wavelength range of 2.2-3.4 μm and finally (3) demonstrate highly-integrated widely tunable sensing PICs.

This integrated photonic demonstration will prove feasibility for future, on-chip, low-cost, compact, robust, and energy-efficient photonic subsystems that will enable a wide range of practical applications. The work performed within this project will generate new fundamental knowledge related to the GaSb material system and build innovations at the photonic components- as well as -IC levels.

To establish such a monolithic platform, widely-tunable semiconductor lasers, photodetectors, low-loss waveguides and 1 × 2 optical splitters in the wavelength range of 2.2-3.4 µm, will be designed, grown, fabricated and tested. Molecular beam epitaxy will be used for the growth of device structures. Multiple, individual SG-DBR (Sampled Grating-Distributed Bragg Reflector) lasers with tuning ranges of 150-250 nm (depending on the center emission wavelength) will be needed to cover the entire targeted range.

As a result, the highly-integrated optical devices and subsystems will simultaneously improve performance and efficiency as well as help meet low size, weight, power and cost (SWaP-C) constraints for next-generation S-MWIR photonic technologies.

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.