High power terahertz vector beam by diffraction radiation

2020 Fiscal Year Final Research Report

• Project/Area Number: 18H03473
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 80040:Quantum beam science-related
• Research Institution: High Energy Accelerator Research Organization
• Principal Investigator: Honda Yosuke 大学共同利用機関法人高エネルギー加速器研究機構, 加速器研究施設, 助教 (40509783)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: テラヘルツ / 電子加速器 / レーザー / ベクトルビーム / 超伝導加速器

Outline of Final Research Achievements

The technologies of the light source in the spectrum range of around 1 THz have not been established. The modern electron accelerators have a possibility to be a high power terahertz source. We have developed a terahertz source based on coherent diffraction radiation mechanism at compact ERL test accelerator.
We have established the beam tuning to realize short bunch beam for efficiently produce coherent radiation in the terahertz range, and to path the beam through a hole mirror target which is the source of the diffraction radiation. The radiation was transported through a newly built vacuum transport line to the experimental room located outside of the accelerator. The spatial profile of the terahertz radiation was measured. The characteristic donuts shape and radial polarization were confirmed by the measurement. It shows efficient transport of the accelerator based terahertz radiation for application experiments.

Free Research Field

加速器

Academic Significance and Societal Importance of the Research Achievements

テラヘルツ光と呼ばれる、周波数1THz付近の領域は、身近な多くの現象の基本的なエネルギースケールである。例えば、分子構造の振動や回転モードのエネルギー準位に対応し、その励起、脱励起はテラヘルツ光を伴う。テラヘルツ光を照射して、これらのモードを選択的に励起することにより、熱平衡状態では実現しない物質の新たな機能を見いだすことが出来る。
テラヘルツ光領域では強度はもちろん、特徴的な光源が少ない。回折放射は偏光特性が空間的に特徴を持つベクトルビームと呼ばれる光の一種である。テラヘルツの領域の特徴的な光源として、応用可能性が拡がる。さらに、本方式は連続運転超伝導加速器により大強度化の可能性もある。