Single mode terahertz quantum cascade amplifier


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Authors
Ren, Y 
Wallis, R 
Shah, YD 
Jessop, DS 
Degl'Innocenti, Riccardo  ORCID logo  https://orcid.org/0000-0003-2655-1997
Abstract

jats:pA terahertz (THz) optical amplifier based on a 2.9 THz quantum cascade laser (QCL) structure has been demonstrated. By depositing an antireflective coating on the QCL facet, the laser mirror losses are enhanced to fully suppress the lasing action, creating a THz quantum cascade (QC) amplifier. Terahertz radiation amplification has been obtained, by coupling a separate multi-mode THz QCL of the same active region design to the QC amplifier. A bare cavity gain is achieved and shows excellent agreement with the lasing spectrum from the original QCL without the antireflective coating. Furthermore, a maximum optical gain of ∼30 dB with single-mode radiation output is demonstrated.</jats:p>

Description
Keywords
Quantum cascade lasers, Optical amplifiers, Laser amplifiers, Antireflective coatings, Refractive index
Journal Title
Applied Physics Letters
Conference Name
Journal ISSN
0003-6951
1077-3118
Volume Title
105
Publisher
AIP Publishing
Sponsorship
Engineering and Physical Sciences Research Council (EP/J007803/1)
Engineering and Physical Sciences Research Council (EP/J017671/1)
This work was supported by the Engineering and Physical Sciences Research Council.