A hybrid analysis method for plasmonic enhanced terahertz photomixer sources

Abstract

A hybrid analysis of a continuous-wave terahertz photomixer source structure with plasmonic nano-grating electrodes is presented. Using the hybrid analysis, the enhancement of the optical power absorption due to the presence of the one-dimensional metallic nano-grating is investigated by defining an absorption enhancement factor. We show that the proposed absorption enhancement factor can be used as a design tool, whose maximization provides the optimum geometrical parameters of the nano-grating. Based on drift-diffusion model, the photocurrent enhancement due to the nano-grating electrodes is studied under three different bias configurations. Moreover, the dependence of the photocurrent on the physical parameters of the photomixer is analyzed.

Unbiased continuous wave terahertz photomixer emitters with dis-similar Schottky barriers

“…Knowing the amplitudes of the optical generation rate and the electric field, throughout the LTG-GaAs, we can readily define the photomixer efficiency, in a similar manner as in [23]…”

Significant performance improvement of a terahertz photoconductive antenna using a hybrid structure

“…20 Recently, nanoplasmonic structures have been incorporated on the PCA to improve the efficiency. [21][22][23][24][25] In a research, Berry et al have incorporated a plasmonic grating to the 3 Â 3 array of logarithmic spiral antennas fabricated on a LT-GaAs layer. 26 They showed that nanoplasmonic resonance at the PCA gap results in high absorption of laser pulse in the photosensitive layer.…”

Nanoplasmonics enhanced terahertz sources

“…Previously, nanoplasmonic structures have been investigated to enhance the performance of THz detectors [17][18][19]. The main advantage of the nanoplasmonic structure for detection is to create a fast sweep out time, and thereby allow for the usage of a low-cost high-mobility long carrier lifetime substrate like semi-insulating GaAs [18,[20][21][22], as opposed to other less common substrates with short carrier lifetimes (such as low-temperature GaAs or GaBiAs) [23][24][25][26][27][28][29][30][31]. For pulsed THz sources, however, the carrier lifetime is not a limiting factor [32], yet nanoplasmonic structures can still provide an advantage, as we will investigate in this work.…”