|
This article is cited in 24 scientific papers (total in 24 papers)
Terahertz radiation
Deflection of a monochromatic THz beam by acousto-optic methods
V. B. Voloshinova, P. A. Nikitina, V. V. Gerasimovb, B. A. Knyazevc, Yu. Yu. Choporovab a Lomonosov Moscow State University, Faculty of Physics
b G I. Budker Institute of Nuclear Physics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk
c Novosibirsk National Research State University
Abstract:
The possibility of controlled deflection of an electromagnetic THz beam of a free-electron laser by acousto-optic (AO) methods has been demonstrated for the first time. The material of the AO deflector was chosen to be single-crystal germanium, which has a fairly large refractive index (n = 4.0) and a relatively low absorption coefficient for electromagnetic waves. The absorption coefficient α in germanium is 0.75 ± 0.02 cm-1 at a wavelength λ = 140 mm. The diffracted beam intensity is shown to be maximum at an effective AO interaction length l = 1/α. A diffraction efficiency of 0.05% at a travelling acoustic wave power of 1.0 W is experimentally obtained. It is established that a change in the ultrasonic frequency from 25 to 39 MHz leads to variation in the external Bragg angle in the range from 19.5° to 27.5°. At a fixed Bragg angle qB = 22.4° the frequency band of diffraction is 4.2 ± 0.1 MHz and the angular range of laser beam scanning reaches 2.5° ± 0.5°. The results obtained indicate that AO interaction can be used for controlled deflection of electromagnetic THz beams.
Keywords:
acousto-optics, THz range, deflector, germanium, Bragg angle, free-electron laser.
Received: 12.04.2013 Revised: 26.06.2013
Citation:
V. B. Voloshinov, P. A. Nikitin, V. V. Gerasimov, B. A. Knyazev, Yu. Yu. Choporova, “Deflection of a monochromatic THz beam by acousto-optic methods”, Kvantovaya Elektronika, 43:12 (2013), 1139–1142 [Quantum Electron., 43:12 (2013), 1139–1142]
Linking options:
https://www.mathnet.ru/eng/qe15195 https://www.mathnet.ru/eng/qe/v43/i12/p1139
|
Statistics & downloads: |
Abstract page: | 245 | Full-text PDF : | 107 | References: | 27 | First page: | 6 |
|