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Broadband surface-emitting THz laser frequency combs with inverse-designed integrated reflectors
- Source :
- APL Photonics 8, 096101 (2023)
- Publication Year :
- 2023
-
Abstract
- THz quantum cascade lasers (QCLs) based on double metal waveguides feature broadband and high-temperature devices for use in spectroscopy and sensing. However, their extreme field confinement produces poor output coupling efficiencies and divergent far-fields. Here, we present a planarized THz QCL with an inverse-designed end facet reflector coupled to a surface-emitting patch array antenna. All the components have been optimized for octave-spanning spectral bandwidths between 2-4 THz and monolithically integrated on the same photonic chip. We demonstrate this experimentally on broadband THz QCL frequency combs, with measured devices showing a seven-fold improvement in slope efficiency compared to devices with a cleaved facet. They feature peak powers of up to 13.5 mW with surface emission into a narrow beam with a divergence of (17.0{\deg}x 18.5{\deg}), while broadband fundamental and harmonic comb states spanning up to 800 GHz are observed.<br />Comment: 6 pages, 5 figures
- Subjects :
- Physics - Optics
Subjects
Details
- Database :
- arXiv
- Journal :
- APL Photonics 8, 096101 (2023)
- Publication Type :
- Report
- Accession number :
- edsarx.2306.10360
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1063/5.0163337