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Title: A comparative study of the plasmon effect in nanoelectrode THz emitters: Pulse vs. continuous-wave radiation

Abstract

Plasmonic field enhancement in terahertz (THz) generation is one of the recently arisen techniques in the THz field that has attracted considerable interest. However, the reported levels of enhancement of THz output power in the literature are significantly different from each other, from less than two times to about two orders of magnitude of enhancement in power, which implies the existence of other major limiting factors yet to be revealed. In this work, the contribution of the plasmonic effect to the power enhancement of THz emitters is revisited. We show that the carrier collection efficiency in a THz emitter with plasmonic nanostructures is more critical to the device performance than the plasmonic field enhancement itself. The strong reverse fields induced by the highly localized plasmonic carriers in the vicinity of the nanoelectrodes screen the carrier collections and seriously limit the power enhancement. This is supported by our experimental observations of the significantly enhanced power in a plasmonic nanoelectrode THz emitter in continuous-wave radiation mode, while the same device has limited enhancement with pulsed radiation. We hope that our study may provide an intuitive but practical guideline in adopting plasmonic nanostructures with an aim of enhancing the efficiency of optoelectronic devices.

Authors:
; ; ; ; ;  [1];  [2];  [3]
  1. Terahertz Basic Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)
  2. Metal-Insulator Transition Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)
  3. Optical Internet Components Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22590540
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 109; Journal Issue: 7; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; EFFICIENCY; ELECTRODES; NANOSTRUCTURES; OPTOELECTRONIC DEVICES; PERFORMANCE; PLASMONS; PULSES

Citation Formats

Moon, Kiwon, Lee, Eui Su, Lee, Il-Min, Han, Sang-Pil, Kim, Hyun-Soo, Park, Kyung Hyun, E-mail: khp@etri.re.kr, Choi, Jeongyong, and Lee, Donghun. A comparative study of the plasmon effect in nanoelectrode THz emitters: Pulse vs. continuous-wave radiation. United States: N. p., 2016. Web. doi:10.1063/1.4961305.
Moon, Kiwon, Lee, Eui Su, Lee, Il-Min, Han, Sang-Pil, Kim, Hyun-Soo, Park, Kyung Hyun, E-mail: khp@etri.re.kr, Choi, Jeongyong, & Lee, Donghun. A comparative study of the plasmon effect in nanoelectrode THz emitters: Pulse vs. continuous-wave radiation. United States. doi:10.1063/1.4961305.
Moon, Kiwon, Lee, Eui Su, Lee, Il-Min, Han, Sang-Pil, Kim, Hyun-Soo, Park, Kyung Hyun, E-mail: khp@etri.re.kr, Choi, Jeongyong, and Lee, Donghun. 2016. "A comparative study of the plasmon effect in nanoelectrode THz emitters: Pulse vs. continuous-wave radiation". United States. doi:10.1063/1.4961305.
@article{osti_22590540,
title = {A comparative study of the plasmon effect in nanoelectrode THz emitters: Pulse vs. continuous-wave radiation},
author = {Moon, Kiwon and Lee, Eui Su and Lee, Il-Min and Han, Sang-Pil and Kim, Hyun-Soo and Park, Kyung Hyun, E-mail: khp@etri.re.kr and Choi, Jeongyong and Lee, Donghun},
abstractNote = {Plasmonic field enhancement in terahertz (THz) generation is one of the recently arisen techniques in the THz field that has attracted considerable interest. However, the reported levels of enhancement of THz output power in the literature are significantly different from each other, from less than two times to about two orders of magnitude of enhancement in power, which implies the existence of other major limiting factors yet to be revealed. In this work, the contribution of the plasmonic effect to the power enhancement of THz emitters is revisited. We show that the carrier collection efficiency in a THz emitter with plasmonic nanostructures is more critical to the device performance than the plasmonic field enhancement itself. The strong reverse fields induced by the highly localized plasmonic carriers in the vicinity of the nanoelectrodes screen the carrier collections and seriously limit the power enhancement. This is supported by our experimental observations of the significantly enhanced power in a plasmonic nanoelectrode THz emitter in continuous-wave radiation mode, while the same device has limited enhancement with pulsed radiation. We hope that our study may provide an intuitive but practical guideline in adopting plasmonic nanostructures with an aim of enhancing the efficiency of optoelectronic devices.},
doi = {10.1063/1.4961305},
journal = {Applied Physics Letters},
number = 7,
volume = 109,
place = {United States},
year = 2016,
month = 8
}
  • It was previously established that the irradiation of the tissue impedes the DNA synthesis; in this connection it was previously shown (Doklady Akad. Nauk SSSR 91: 1183 (1953)) that incorporation of P/sup 32/ into the nucleic acids of the spleen is greatly dependent on the fact whether that organ alone or the whole animal was irradiated. In order to clarify the direct effect of radiation, this problem was further studied by introducing labeled predecessors into the DNA molecule, using tissue nuclei separated from the cytoplasm. The formation of purine and pyrimidine bases was investigated by using C/suip 14/--formiate and C/more » sup 14/- adenine. The first conmpound is incorporated only in the thymine and the second only in the DNA adenine; this may be used in comparing the effect of ionizing radiations on these reactions. Results indicated that after total irradiation of rats to 1000 r, the ability of the tissue nuclei isolated from the thymus to incorporate either of these compounds is greatly reduced. Irradiation of separate tissue nuclei of the thymus resulted in a slight depression of the incorporation process of the C/sup 14/--formiate into the DNA thymine while the corresponding adenine process was hardly affected. In general, irradiation in vivo caused more injury than exposure of separate organs to ionizing radiation. (TTT)« less
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  • Investigations have been carried out concerning the effects of microwave (MW) exposure on the aminoacyl-transfer ribonucleic acid (tRNA) synthetase of the progeny of females that were exposed during their entire period of gestation (19 days). The changes caused by continuous-wave (CW) and amplitude-modulated (AM) MW radiation have been compared. CFLP mice were exposed to MW radiation for 100 min each day in an anechoic room. The MW frequency was 2.45 GHz, and the amplitude modulation had a 50 Hz rectangular waveform (on/off ratio, 50/50%). The average power density exposure was 3 mW/cm{sup 2}, and the whole body specific absorption ratemore » (SAR) was 4.23 {+-} 0.63 W/kg. The weight and mortality of the progeny were followed until postnatal day 24. Aminoacyl-tRNA synthetase enzymes and tRNA from the brains and livers of the offspring (461 exposed, 487 control) were isolated. The aminoacyl-tRNA synthetase activities were determined. The postnatal increase of body weight and organ weight was not influenced by the prenatal MW radiation. The activity of enzyme isolated form the brain showed a significant decrease after CW MW exposure, but the changes were not significant after 50 Hz AM MW exposure. The activity of the enzyme isolated from liver increased under CW and 50 Hz modulated MW.« less