Photoconductive terahertz near-field detector with a hybrid nanoantenna array cavity
- Univ. College London, London (United Kingdom); Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Nanoscale structuring of optical materials leads to modification of their properties and can be used for improving efficiencies of photonic devices and for enabling new functionalities. In ultrafast optoelectronic switches for generation and detection of terahertz (THz) radiation, incorporation of nanostructures allows us to overcome inherent limitations of photoconductive materials. We propose and demonstrate a nanostructured photoconductive THz detector for sampling highly localized THz fields, down to the level of λ/150. The nanostructure that consists of an array of optical nanoantennas and a distributed Bragg reflector forms a hybrid cavity, which traps optical gate pulses within the photoconductive layer. The effect of photon trapping is observed as enhanced absorption at a designed wavelength. This optically thin photoconductive THz detector allows us to detect highly confined evanescent THz fields coupled through a deeply subwavelength aperture as small as 2 μm (λ/150 at 1 THz). As a result, by monolithically integrating the THz detector with apertures ranging from 2 to 5 μm we realize higher spatial resolution and higher sensitivity in aperture-type THz near-field microscopy and THz time-domain spectroscopy.
- Research Organization:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- AC04-94AL85000
- OSTI ID:
- 1238657
- Report Number(s):
- SAND-2015-9128J; 608008
- Journal Information:
- ACS Photonics, Vol. 2, Issue 12; ISSN 2330-4022
- Publisher:
- American Chemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Similar Records
Plasmonics-enhanced photoconductive terahertz detector pumped by Ytterbium-doped fiber laser
Highly efficient terahertz photoconductive metasurface detectors operating at microwatt-level gate powers