Abstract
Aperture-transmission measurements have been investigated as a way to characterize the focus of the subterahertz (sub-THz) beam in a time-domain spectroscopic system. Although measurement methods with a fixed time delay, like the knife-edge measurement, are often used to characterize the focusing of THz or sub-THz beams, such methods sometimes produce data that is difficult to interpret, for example, negative beam intensity. On the other hand, the data obtained by the aperture-transmission measurement is simple; the beam is considered tightly focused if the transmittance is high. However, unintentional effects occur when a metal aperture is used to characterize the focusing and a metal structure is used to assist the beam focusing, because parts of the metal structure are placed adjacent to the metal aperture. Here, we used an insulator aperture and found that it could be used for the characterization of focusing without the unintentional effects.
© 2016 Optical Society of America
Full Article | PDF ArticleMore Like This
Osamu Morikawa, Kohji Yamamoto, Kazuyoshi Kurihara, Masahiko Tani, Fumiyoshi Kuwashima, and Masanori Hangyo
J. Opt. Soc. Am. B 33(9) 1940-1948 (2016)
Osamu Morikawa, Ai Hattori, Kohji Yamamoto, Kazuyoshi Kurihara, Takashi Furuya, Fumiyoshi Kuwashima, Hideaki Kitahara, and Masahiko Tani
J. Opt. Soc. Am. B 41(5) 1254-1260 (2024)
Amit Agrawal, Tatsunosuke Matsui, Z. Valy Vardeny, and Ajay Nahata
J. Opt. Soc. Am. B 24(9) 2545-2555 (2007)