CUED Publications database

External amplitude and frequency modulation of a terahertz quantum cascade laser using metamaterial/graphene devices.

Kindness, SJ and Jessop, DS and Wei, B and Wallis, R and Kamboj, VS and Xiao, L and Ren, Y and Braeuninger-Weimer, P and Aria, AI and Hofmann, S and Beere, HE and Ritchie, DA and Degl'Innocenti, R (2017) External amplitude and frequency modulation of a terahertz quantum cascade laser using metamaterial/graphene devices. Sci Rep, 7. 7657-.

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Abstract

Active control of the amplitude and frequency of terahertz sources is an essential prerequisite for exploiting a myriad of terahertz applications in imaging, spectroscopy, and communications. Here we present a optoelectronic, external modulation technique applied to a terahertz quantum cascade laser which holds the promise of addressing a number of important challenges in this research area. A hybrid metamaterial/graphene device is implemented into an external cavity set-up allowing for optoelectronic tuning of feedback into a quantum cascade laser. We demonstrate powerful, all-electronic, control over the amplitude and frequency of the laser output. Full laser switching is performed by electrostatic gating of the metamaterial/graphene device, demonstrating a modulation depth of 100%. External control of the emission spectrum is also achieved, highlighting the flexibility of this feedback method. By taking advantage of the frequency dispersive reflectivity of the metamaterial array, different modes of the QCL output are selectively suppressed using lithographic tuning and single mode operation of the multi-mode laser is enforced. Side mode suppression is electrically modulated from ~6 dB to ~21 dB, demonstrating active, optoelectronic modulation of the laser frequency content between multi-mode and single mode operation.

Item Type: Article
Subjects: UNSPECIFIED
Divisions: Div B > Photonics
Div B > Solid State Electronics and Nanoscale Science
Depositing User: Cron Job
Date Deposited: 17 Jul 2017 18:57
Last Modified: 18 Nov 2017 21:56
DOI: