High-speed and wide-range swept source using acousto-optic deflector as tunable grating and its application on OCT

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04922
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 30020:Optical engineering and photon science-related
• Research Institution: Niigata University
• Principal Investigator: Suzuki Takamasa 新潟大学, 自然科学系, 教授 (40206496)
• Co-Investigator(Kenkyū-buntansha): 崔 森悦 新潟大学, 自然科学系, 准教授 (60568418)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 波長走査光源 / OCT / 音響光学デバイス / 周期可変回折格子

Outline of Final Research Achievements

A wavelength scanning light sources (SSs) using an acousto-optic (AO) device as tunable grating were constructed. Additionally, its characteristics and performance as an OCT light source were examined. The SSs were assembled in three wavelength bands: 840nm, 1060nm, and 1310nm. We confirmed that the wavelength scanning characteristics in the 840nm and 1310nm bands agreed with the the theoretical calculations. However, in the 1060nm band, we could not make detailed characteristics evaluations because of the heat-dissipation problem at the AO device. Further, we confirmed that the OCT equipped with our SS operating at the 1310 nm band can accurately measured the cross-sectional structure of the object.
All results of the research were presented at one international conference and two academic papers, and one patent application was filed.

Free Research Field

光計測

Academic Significance and Societal Importance of the Research Achievements

眼や皮膚などに光を当てて非接触かつ非侵襲で計測し、医療診断を行う光コヒーレンストモグラフィ（OCT）と呼ばれる装置がある。OCTの光源としてよく用いられるのが波長を時間的に変化させる波長走査光源（SS）である。
これまでSSの構築には、波長選択と光偏向を行う光学素子をセットで用いることが当然と考えられてきたが、本研究では、その両方を1つの素子で実現する手法を提案し、その優位性を明らかにした（学術的意義）。本研究で提案したSSは、コンパクトかつ安価であり、波長の走査速度も速い。また、イメージングに必要な信号処理も高速に行えるため、高速かつ高精度なOCT装置を実現することが可能となる（社会的意義）。