Terahertz emission based on large-area photoconductive emitters illuminated via beam interference
نویسندگان
چکیده
The use of beam interference in combination with a large-area photoconductive emitter for the generation of pulsed terahertz (THz) radiation is presented. An interference pattern with a period twice that of the THz emitter is generated with a transmission phase grating, placed directly in front of the photoconductive emitter. This way, efficient THz generation is achieved with a single metallisation layer and a single lithography step in the fabrication technology of the THz emitter.
منابع مشابه
THz beam focusing EXTENDED Paul Edit
Illuminated by ultrashort optical pulses, large area multiplex terahertz semiconductor emitters that work on photoDember currents and Schottky potentials radiate a directional electromagnetic terahertz pulse which is controlled by the angular spectrum of the incident optical beam. Using the lens that focuses the incident near infra-red pulse, we have demonstrated THz emission focusing in free s...
متن کاملImpact of substrate characteristics on performance of large area plasmonic photoconductive emitters.
We present a comprehensive analysis of terahertz radiation from large area plasmonic photoconductive emitters in relation with characteristics of device substrate. Specifically, we investigate the radiation properties of large area plasmonic photoconductive emitters fabricated on GaAs substrates that exhibit short carrier lifetimes through low-temperature substrate growth and through epitaxiall...
متن کاملLarge-area sub-micron gap interdigitated THz emitters fabricated by interference lithography and angle evaporation
Interference-lithography and a self-aligning angle-evaporation technique are employed to fabricate interdigitated photoconductive terahertz (THz) emitters. The devices have a large active area for high directivity and submicron spaced electrodes for high internal electric fields at low bias voltages. The fabrication process offers the advantage that only one patterning step is needed to generat...
متن کاملLarge-area laser-driven terahertz emitters
Intense terahertz em itters are one of the most important components of terahertz (THz) time-domain spectroscopy systems. In this presented report, the development of THz emitters over the last two decades is reviewed, and an outlook for future THz emitters is given. The physical principle behind the THz generation process is discussed for two types of emitters: state-of-the-art large-area phot...
متن کاملA polarization-insensitive plasmonic photoconductive terahertz emitter
We present a polarization-insensitive plasmonic photoconductive terahertz emitter that uses a two-dimensional array of nanoscale cross-shaped apertures as the plasmonic contact electrodes. The geometry of the cross-shaped apertures is set to maximize optical pump absorption in close proximity to the contact electrodes. The two-dimensional symmetry of the cross-shaped apertures offers a polariza...
متن کامل