External seminar archive:

Amplitude/frequency modulation and detection of THz quantum cascade lasers with hybrid metamaterial/graphene integrated arrays

23 February 2017
Dr Riccardo Degl'Innocenti, University Of Cambridge

Terahertz (THz) science and technology has recently experienced impressive progress thanks to several unique applications and the advent of powerful solid state sources such as the quantum cascade laser (QCL). However, the lack of suitable, fast optoelectronic modulators and detectors has so far hindered this spectral region from reaching its full potential in many demanding sectors such as spectroscopy, communications and imaging.

Plasmonic metamaterial devices have already established themselves as versatile tools for the realisation of efficient integrated devices in the mid infrared frequency range when combined with active materials such as graphene. Such metamaterial/graphene devices are natural candidates to be used in the THz frequency range where naturally occurring materials have a poor electromagnetic response.

The implementation of these devices with QCLs for fast, reconfigurable amplitude and frequency modulation as well as terahertz detection represents an important step towards the achievement of an integrated THz platform. This will enable the full exploitation of QCLs in spectroscopy and communication applications, where a precise all-electronic control of the emission is demanded.

I will present the latest results on modulation and detection using THz QCLs with active metamaterial/graphene arrays achieved in the Semiconductor Physics Group in the Cavendish Laboratory.


  1. R. Degl’Innocenti et al., ACS Nano, 8, 2548-2554 (2014).

  2. R. Degl’Innocenti et al., ACS Photonics, 3, 464-470 (2016).

  3. D. Jessop et al., Appl. Phys Lett., 108, 171101 (2016).

  4. Y. Ren et al., Appl. Phys. Lett., 107, 011107 (2015).

  5. R. Degl’Innocenti, et al., ACS Photonics, 3, 1747-1753 (2016).