TERAHERTZ MICROLENS ARRAY EMITTER BASED ON THE TRANSVERSE DEMBER CROSS EFFECT
V. D. Antsygin, A. S. Konchenko, V. P. Korol’kov, A. A. Mamrashev, N. A. Nikolaev, O. I. Potaturkin
1Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, pr. Akademika Koptyuga 1, Novosibirsk, 630090 Russia
antsigin@iae.nsk.su
2Novosibirsk State University, ul. Pirogova 2, Novosibirsk, 630090 Russia
viktork@iae.nsk.su
Keywords: terahertz radiation, Dember effect, Talbot effect, femtosecond laser, array illuminator
Abstract
A new method for generating terahertz radiation by exposure to femtosecond laser pulses on the semiconductor surface is proposed. The essence of this method is that the exciting radiation intensity is subjected to spatial modulation by using a microlens array and by shading a part of the semiconductor surface by metal stripes. This gives rise to a concentration gradient of photo carriers along the surface at the sharp boundary of the metallic coating in the semiconductor (transverse Dember photoelectric effect), and its relaxation for times of ~1 ps results in the emission of electromagnetic pulses of the terahertz range. A terahertz emitter model based on the proposed method was developed and designed, its efficiency was demonstrated, and methods for increasing its efficiency were considered.
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