Open AccessBroadband metasurface design for terahertz quantum‐cascade VECSEL
Author(s) -
Curwen C.A.,
Reno J.L.,
Williams B.S.
Publication year - 2020
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
ISSN - 1350-911X
DOI - 10.1049/el.2020.1963
Subject(s) - terahertz radiation , broadband , cascade , optoelectronics , photomixing , optics , quantum cascade laser , materials science , quantum , physics , terahertz metamaterials , terahertz spectroscopy and technology , far infrared laser , laser , engineering , quantum mechanics , chemical engineering
A broadband active metasurface is designed around quantum‐cascade (QC) gain material for use in a broadband tunable QC vertical external‐cavity surface‐emitting laser (VECSEL). The metasurface is based on a unit cell containing two resonant waveguide elements that couple with the periodicity of the metasurface to produce a multi‐resonant reflection spectrum. Simulated reflectance spectra exhibit full‐width half‐maximum bandwidths up to 50% of the centre frequency. The tested QC‐VECSEL demonstrates up to 15 mW of peak pulse power at 77 K and supports multimode lasing from 2.85 to 3.9 THz (>30% fractional bandwidth around 3.37 THz). The frequency coverage is limited by how short the cavity can be made, rather than the metasurface bandwidth. Consistent multimoding results from non‐uniform distribution of spectral energy across the surface.