Aperture transmission measurements for characterization of focusing of subterahertz radiation

作者：Morikawa Osamu^*; Yamamoto Kohji; Kurihara Kazuyoshi; Tani Masahiko; Kuwashima Fumiyoshi; Hangyo Masanori

来源：Journal of the Optical Society of America B-Optical Physics, 2016, 33(7): 1456.

DOI：10.1364/JOSAB.33.001456

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.

• 出版日期2016-7-1