Showing posts with label Yuri Avetisyan. Show all posts
Showing posts with label Yuri Avetisyan. Show all posts

Wednesday, August 16, 2017

Abstract-High Efficient Terahertz Generation Using Tilted-Pulse-Front Photoexcitation of Semiconductor Surface



Yuri Avetisyan, Armen Makaryan, and Masayoshi Tonouchi

https://www.osapublishing.org/abstract.cfm?uri=cleo_at-2017-JW2A.109&origin=search

It is shown that photoexcitation of InAs surface with tilted-front laser pulses allows controlling the direction of terahertz emission and by that way achieving significant increase in the generated power.
© 2017 OSA

Tuesday, March 12, 2013

Abstract-Tunable narrowband terahertz generation in lithium niobate crystals using a binary phase mask


Caihong Zhang, Yuri Avetisyan, Gevorg Abgaryan, Iwao Kawayama, Hironaru Murakami, and Masayoshi Tonouchi »View Author Affiliations

http://www.opticsinfobase.org/ol/abstract.cfm?uri=ol-38-6-953


We present a simple scheme of narrowband terahertz (THz) generation by optical rectification in the lithium niobate crystal covered by a binary phase mask. It is shown that a single-domain crystal illumination by spatiotemporal shaped fs-laser pulses is equivalent to the formation of a transversally patterned, quasi-phase-matching structure. Decrease of the optical beam size on the mask leads to an increase of the THz-wave linewidth from 17 GHz to a few THz. The frequency of the generation was tuned in the range of 0.4–1.0 THz by building images of the mask in the crystal with various magnifications. Application results of the presented THz source for measuring transmittance of the superconducting NbN thin film in the 4.2–15 K temperature range are also presented.
© 2013 Optical Society of America