Mid-infrared metasurface VECSELs
Abstract
The goal of this proposal is to develop quantum-cascade (QC) vertical external cavity surface emitting lasers (VECSELs) in the mid-infrared spectral range based upon gain-loaded metasurfaces. This is proposed a path for (a) high brightness mid-IR sources with scalable output power (up to tens of Watts) in a circular diffraction limited beam, and (b) a platform for multifunctional lasers associated with the ability to locally engineer the amplitude, phase, and polarization response of the metasurface. The specific goal of one year program is a proof of concept demonstration of a metasurface VECSEL in the LWIR range (i.e. 8-12 micron). If initial demonstration is successful, we will investigate metasurface VECSELs with dynamically switchable output polarization, as an example of the multi-functional laser concept. The VECSEL is an attractive architecture to achieve high-power single-transverse-mode operation with excellent Gaussian beam quality. While desirable, the VECSEL concept could not ordinarily be implemented for a quantum-cascade laser, because the intersubband selection rule prevents interaction of the gain medium with surface incident radiation. Our group has recently demonstrated the first quantum-cascade VECSEL in the THz frequency range by using a novel metasurface made up of sub-wavelength antenna-coupled sub-cavities loaded with QC-laser gain material; this creates an active amplifying mirror which serves as one mirror in an open cavity. Here we propose to demonstrate the metasurface QC-VECSEL approach in the mid-infrared range. The technological impact is potentially high, as both sensing applications and infrared countermeasures demand high performance mid-IR sources. Novelty lies in the fact that the THz approach cannot simply be scaled to the mid-IR Ð the metallic losses would become excessive and prevent operation. Instead we propose several new schemes for low-loss QC metasurfaces based upon plasmonic and all-dielectric approaches.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 20, 2019
- Source ID
- W911NF1710004
Entities
People
- Benjamin S. Williams
Organizations
- Army Contracting Command
- Defense Advanced Research Projects Agency
- University of California, Los Angeles