Liang, G, Liang, H, Zhang, Y et al. (6 more authors)
(2013)
Low divergence single-mode surface-emitting concentric-circular-grating terahertz quantum cascade lasers.
Optics Express, 21 (26).
31872 - 31882.
ISSN 1094-4087
Abstract
We report the design, fabrication and experimental characterization of surface-emitting terahertz (THz) frequency quantum cascade lasers (QCLs) with distributed feedback concentric-circular-gratings. Single-mode operation is achieved at 3.73 THz with a side-mode suppression ratio as high as ~30 dB. The device emits ~5 times the power of a ridge laser of similar dimensions, with little degradation in the maximum operation temperature. Two lobes are observed in the far-field emission pattern, each of which has a divergence angle as narrow as ~13.5° × 7°. We demonstrate that deformation of the device boundary, caused by anisotropic wet chemical etching is the cause of this double-lobed profile, rather than the expected ring-shaped pattern.
Metadata
Item Type:
Article
Authors/Creators:
Liang, G
Liang, H
Zhang, Y
Li, L
Davies, AG
Linfield, E
Yu, SF
Liu, HC
Wang, QJ
Copyright, Publisher and Additional Information:
(c) 2013, Optical Society of America. This paper was published in Optics Express and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: [http://dx.doi.org/10.1364/OE.21.031872]. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.
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