5/14：講演会のお知らせ　高久諒太 先生　（物理学科 助教）

2026年05月11日

日　時： 5月14日 (木)　13時 ～
Date and Time: May 14 (Thu) 13:00 -
場　所：24講義室
Place: Lecture room 24
発表者：高久諒太 先生（物理学科　助教）
Lecturer：Dr. Ryota Takaku (Ishino Lab. Asst.Prof.)

題目：「レーザー加工で新しい宇宙観測への窓を作る」
Title："Opening a new window for observational cosmology using a laser fabrication"

Abstract
Sapphire, alumina, and silicon are attractive materials for
millimeter- and submillimeter-wave optical elements, such as a window, filter, and lense. In addition, a continuously rotating half-wave plate (HWP) is used in CMB polarization observations to mitigate the effect of 1/f noise and probe cosmic inflation. Although these materials have advantages such as high thermal conductivity and low dielectric loss, their refractive indices are higher than 3, which require a broadband anti-reflection coating (ARC).
Sub-wavelength structures (SWS), also known as moth-eye structures, function as a broadband ARC. Ultra-short pulsed laser ablation is a useful method for fabricating SWS on such hard materials. We have developed a laser-machining method to fabricate SWS for millimeter- and submillimeter-wave applications, with the aim of integrating them into cosmological and astrophysical telescopes.
I will introduce results demonstrating that our technology has been used in actual telescopes, discuss the statistical contribution of an actual HWP with SWS to cosmological parameter estimation, and describe potential extensions of our technology.

世話人：異分野基礎科学研究所 吉村浩司　(内8499)