Citation:
Riccardo Degl'Innocenti, Long Xiao, Stephen J Kindness, et al., Bolometric detection of terahertz quantum cascade laser radiation with graphene-plasmonic antenna arrays. Journal of Physics D: Applied Physics, 2017, Volume 50, Number 17, Article number 174001
Abstract:
We present a fast room temperature terahertz detector based on graphene loaded plasmonic
antenna arrays. The antenna elements, which are arranged in series and are shorted
by graphene, are contacting source and drain metallic pads, thus providing both the
optical resonant element and the electrodes. The distance between the antenna’s arms of
approximately 300 nm allows a strong field enhancement in the graphene region, when the
incident radiation is resonant with the antennas. The current passing through the source and
drain is dependent on the graphene’s conductivity, which is modified by the power impinging
onto the detector as well as from the biasing back-gate voltage. The incident radiation power is
thus translated into a current modification, with the main detection mechanism being attributed
to the bolometric effect. The device has been characterized and tested with two bound to
continuum terahertz quantum cascade lasers emitting at a single frequency around 2 THz and
2.7 THz yielding a maximum responsivity of ~2 mA W−1.