Title :
Improved efficiency of photoconductive THz source by selective enhancement of electric fields by patterning
Author :
Singh, Ashutosh ; Nikesh, V.V. ; Surdi, Harshad ; Prabhu, S.S. ; Dohler, Gottfried H.
Author_Institution :
Tata Inst. of Fundamental Res., Mumbai, India
Abstract :
Improving the THz emission efficiency of the THz sources has been a major research goal for several years. We present here an approach to improve the efficiency of a THz Photoconductive Antenna (PCA) fabricated on a Semi-Insulating (SI) GaAs substrate by etching out a grating like structure on the substrate surface before contact deposition. After patterning, we have observed enhancement in THz power emission compared to the emitted THz power from the usual un-patterned regions of the PCA. This enhancement in emitted THz amplitude is attributed to the enhancement in applied electric field in the unetched volume of GaAs as well as enhanced incident exciting photon confinement in the same un-etched volume of the patterned region.
Keywords :
III-V semiconductors; antennas; etching; gallium arsenide; photoconducting devices; terahertz waves; GaAs; PCA; THz photoconductive antenna; THz power emission efficiency; applied electric field enhancement; contact deposition; emitted THz amplitude; enhanced incident exciting photon confinement; grating like structure etching; patterned region; photoconductive THz source; selective electric field enhancement; semiinsulating substrate; substrate surface; Electric fields; Electrodes; Etching; Gallium arsenide; Gratings; Principal component analysis; Substrates;
Conference_Titel :
Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), 2013 38th International Conference on
Conference_Location :
Mainz
DOI :
10.1109/IRMMW-THz.2013.6665662
