Transient Analysis of THz-QCL Pulses Using NbN and YBCO Superconducting Detectors
Scheuring, A, Dean, P, Valavanis, A et al. (12 more authors)
(2013)
Transient Analysis of THz-QCL Pulses Using NbN and YBCO Superconducting Detectors.
IEEE Transactions on Terahertz Science and Technology, 3 (2).
pp. 172-179.
ISSN 2156-342X
Abstract
We report the time-domain analysis of fast pulses emitted by a quantum cascade laser (QCL) operating at ~3.1 THz using superconducting THz detectors made from either NbN or YBa2Cu3O7- (YBCO) thin films. The ultra-fast response from these detectors allows resolution of emission features occurring on a nanosecond time-scale, which is not possible with commercially available Ge or InSb bolometers owing to their much larger time constants. We demonstrate that the time-dependent emission can be strongly affected by relatively small variations in the driving pulse. The QCL output power–current relationship was determined, based on correlation of the time-dependent emission of radiation with current flow in the QCL, under different QCL bias conditions. We show that this relationship differs from that obtained using bolometric detectors that respond only to the integrated pulse energy. The linearity of the detectors, and their agreement with measurements using a Ge bolometer, was also established by studying the QCL emission as a function of bias voltage and excitation pulse length. This measurement scheme could be readily applied to the study of ultra-fast modulation and mode-locking of THz-QCLs.
Metadata
Authors/Creators:
Scheuring, A
Dean, P
Valavanis, A
Stockhausen, A
Thoma, P
Salih, M
Khanna, SP
Chowdhury, S
Cooper, JD
Grier, A
Wuensch, S
Il in, K
Linfield, EH
Davies, AG
Siegel, M
Copyright, Publisher and Additional Information:
(c) 2013, Institute of Electrical and Electronics Engineers. This is an author produced version of a paper accepted for publication in IEEE Transactions on Terahertz Science and Technology. Uploaded in accordance with the publisher's self-archiving policy. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)