Mid-IR PCSELs with low threshold current and high beam quality.
Abstract
Light detection and ranging (LiDAR) is the critical technological element for a variety of robotic applications. Modern LiDAR systems must rely on semiconductor lasers with high-quality, low-divergence, and symmetric beams. These lasers can be integrated with the most automation sensor schemes without complicated beam shaping optical systems. Single mode, high power laser emission from a large area aperture can be achieved in photonic crystal surface emitting lasers (PCSEL). The essential element of PCSEL cavity is a photonic crystal layer incorporated into the laser heterostructure. This photonic crystal acts as a distributed feedback cavity element providing in-plane optical feedback necessary for the start of lasing and, simultaneously, outcoupling of the stimulated emission into the vertical direction. The capability of the PCSEL concept to generate high power ultra-low divergence single frequency output beams was demonstrated within a GaAs material system. The near-infrared GaAs-based PCSELs generated high peak power of ~10 W in nearly diffraction-limited beam with divergence angle of fraction of degree. High-power PCSELs operating in spectral region above 2 µm and suitable for remote sensing, free space communication and eye safe LiDAR applications are currently unavailable. The goal of this proposal is to demonstrate the watt-level surface emission at wavelengths up to 3 µm in a single lobe beam with sub-degree divergence. The technological achievement behind the success of GaAs-based PCSEL is the development of the photonic crystal incorporated into the laser waveguide with the help of epitaxial regrowth technology. Stony Brook University recently reported electrically pumped PCSELs operating in spectral range above 2 µm. We demonstrated experimentally the feasibility of fabrication of the GaSb-based fully regrown PCSEL heterostructures operating in the mid-infrared region of the spectrum. This result was obtained using the in-house developed air-hole retaining regrowth technique. The proposed efforts will focus on further advancement of GaSb-based PCSEL technology to attain control of the laser characteristics by precise tuning of the the parameters of buried photonic crystal layer. The device modeling and characterization techniques will be used to optimize the design of PCSEL nanostructures to achieve room temperature high efficiency laser operation.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 05, 2022
- Source ID
- W911NF2210068
Entities
People
- L. Shterengas
Organizations
- Army Contracting Command
- Research Foundation for the State University of New York
- United States Army