Final published version
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - External amplitude and frequency modulation of a terahertz quantum cascade laser using metamaterial/graphene devices
AU - Kindness, S. J.
AU - Jessop, D. S.
AU - Wei, B.
AU - Wallis, R.
AU - Kamboj, V. S.
AU - Xiao, L.
AU - Ren, Y.
AU - Braeuninger-Weimer, P.
AU - Aria, A. I.
AU - Hofmann, S.
AU - Beere, H. E.
AU - Ritchie, D. A.
AU - Degl'innocenti, Riccardo
PY - 2017/8/9
Y1 - 2017/8/9
N2 - 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.
AB - 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.
KW - Metamaterials
KW - Optimcal properties and devices
KW - Quantum cascade lasers
KW - Semiconductor lasers
KW - Terahertz optics
U2 - 10.1038/s41598-017-07943-w
DO - 10.1038/s41598-017-07943-w
M3 - Journal article
AN - SCOPUS:85027161303
VL - 7
JO - Scientific Reports
JF - Scientific Reports
SN - 2045-2322
IS - 1
M1 - 7657
ER -