Badhwar, S and Puddy, R and Kidambi, PR and Sibik, J and Brewer, A and Freeman, JR and Beere, HE and Hofmann, S and Zeitler, JA and Ritchie, DA (2012) Indirect modulation of a terahertz quantum cascade laser using gate tunable graphene. IEEE Photonics Journal, 4. pp. 1776-1782. ISSN 1943-0655Full text not available from this repository.
We bring together two areas of terahertz (THz) technology that have benefited from recent advancements in research, i.e., graphene, a material that has plasmonic resonances in the THz frequency, and quantum cascade lasers (QCLs), a compact electrically driven unipolar source of THz radiation. We demonstrate the use of single-layer large-area graphene to indirectly modulate a THz QCL operating at 2.0 THz. By tuning the Fermi level of the graphene via a capacitively coupled backgate voltage, the optical conductivity and, hence, the THz transmission can be varied. We show that, by changing the pulsing frequency of the backgate, the THz transmission can be altered. We also show that, by varying the pulsing frequency of the backgate from tens of Hz to a few kHz, the amplitude-modulated THz signal can be switched by 15% from a low state to a high state. © 2009-2012 IEEE.
|Uncontrolled Keywords:||Graphene modulator quantum cascade laser (QCL) terahertz (THz)|
|Depositing User:||Cron job|
|Date Deposited:||16 Jul 2015 13:13|
|Last Modified:||08 Oct 2015 11:52|