Speaker
Prof.
Vladimir Pavelyev
(Samara University)
Description
The emergence of coherent, high power sources of THz radiation [1] has formed a need for optical elements to control this radiation. It is known that high-power THz beams can be controlled by silicon diffractive optical elements (DOEs) [2,3,4]. The lithographic etching of a silicon substrate [2,3,4] has disadvantages: fabrication of multi-level elements by lithographic etching requires an expensive and complicated procedure of photomask alignment, and binary (two-level) elements have limited energy efficiency. A possibility of the microfabrication of a high-effective power silicon diffractive optics for terahertz range by laser ablation is investigated [5]. A four-level silicon diffractive THz Fresnel lens has been fabricated for the first time by femtosecond laser ablation [5]. High repetition (f = 200 kHz) femtosecond Yb:YAG laser was used for the formation of micro-relief at the silicon surface. Features of the lens were investigated in the beam of the free electron laser at the wavelength of 141 µm. The measured diffractive efficiency of the lens is in good agreement with the theoretical prediction [5].
The experiments have shown the feasibility of laser ablation of the silicon surface to fabricate effective multilevel THz DOEs.
Improving the proposed technology of forming a silicon microrelief, in particular increasing the number of its quantization levels, will eventually increase the energy efficiency of silicon DOEs designed to control beams of THz radiation.
1. Knyazev, B. A. Novosibirsk terahertz free electron laser: instrumentation development and experimental achievements / B.A. Knyazev, G.N. Kulipanov, N.A. Vinokurov// Measur. Sci. Techn. – 2010. – Vol. 21. – P. 13.
2. Agafonov, A.N. Silicon diffractive optical elements for high-power monochromatic terahertz radiation / A.N. Agafonov, B.O. Volodkin, A.K. Kaveev, B.A. Knyazev, G.I. Kropotov, V.S. Pavel’ev, V.A. Soifer, K.N. Tukmakov, E.V. Tsygankova, Yu.Yu. Choporova // Optoelectronics, Instrumentation and Data Processing. – 2013. – Vol. 49, Issue 2 – P. 189-195.
3. Agafonov A.N. Control of transverse mode spectrum of Novosibirsk free electron laser radiation // A.N. Agafonov, Yu.Yu. Choporova, A.V. Kaveev, B.A. Knyazev, G.I. Kropotov, V.S. Pavelyev, K.N. Tukmakov, B.O. Volodkin, /Applied Optics. – 2015 – Vol. 54, N. 12 – 3635-3639.
4. Knyazev B.A. Generation of Terahertz Surface Plasmon Polaritons Using Nondiffractive Bessel Beams with Orbital Angular Momentum// Yu.Yu. Choporova, M.S. Mitkov, V.S. Pavelyev, B.O. Volodkin/Phys. Rev. Lett.- 2015-Vol 115 -163901.
5. Komlenok, M.S. Fabrication of a multilevel THz Fresnel lens by femtosecond laser ablation// B.O. Volodkin, B.A. Knyazev, V.V. Kononenko, T.V. Kononenko, V.I. Konov, V.S. Pavelyev, V.A. Soifer, K.N. Tukmakov, Yu.Yu. Choporova/Quantum Electronics-2015-Vol. 45, N 10- 933 –936.
Primary author
Prof.
Vladimir Pavelyev
(Samara University)
Co-authors
Prof.
Boris Knyazev
(Budker Institute of Nuclear Physics)
Mr
Boris Volodkin
(Samara University, 34, Moskovskoe shosse, Samara, 443086, Russian Federation)
Dr
Maxim Komlenok
(A.M. Prokhorov General Physics Institute RAS, 38 Vavilov str., 119991, Moscow, Russia)
Dr
Taras Kononenko
(A.M. Prokhorov General Physics Institute RAS, 38 Vavilov str., 119991, Moscow, Russia)
Prof.
Viktor Soifer
(Samara University, 34, Moskovskoe shosse, Samara, 443086, Russian Federation)
Prof.
Vitaly Konov
(A.M. Prokhorov General Physics Institute RAS, 38 Vavilov str., 119991, Moscow, Russia)
Ms
Yulia Choporova
(Budker Institute of Nuclear Physics)
