Fresnel lens having a special blazed shape for collecting sun light

2018 Fiscal Year Final Research Report

• Project/Area Number: 15K04700
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Optical engineering, Photon science
• Research Institution: Tokyo Polytechnic University
• Principal Investigator: Shibuya Masato 東京工芸大学, 工学部, 名誉教授 (10339799)
• Research Collaborator: NAKADATE suezou ; HIRAMATSU takashi ; KASAMATSU hidenori
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 太陽光集光 / フレネルレンズ / DOE / 正弦条件 / 両側ブレーズ / 片側ブレーズ

Outline of Final Research Achievements

In order to solve global warming, utilization of natural energy is desired, and an optical system for efficiently guiding sunlight to a light transmission path such as a glass rod is required. However, conventionally used focusing optics are not sufficient. We have found the basic principle that a Fresnel lens should have to be efficient even when the sun is incident obliquely.
We confirm the correctness of this principle in detail by theoretical study and numerical design. Furthermore, we derive the basic design principle of the both-side blazed Fresnel lens for general case. We also clarified the unavoidable aberration generation mechanism of one-sided blazed Fresnel lens and formulated it quantitatively.

Free Research Field

光学設計開発

Academic Significance and Societal Importance of the Research Achievements

従来に比べて太陽光が斜めに入射しても効率よくガラスロッドなどの光伝送路に集光できるため、自然エネルギー利用効率をげることができ、地球温暖化の解決への一助となる。
また、一般的なブレーズ型フレネルレンズの収差発生機構を明確にしたことは、フレネルレンズやDOE（Diffractive Optical Element)の設計に有用である。特に、高精細な光学系にDOEを用いるときの適用限界を導いたことは、このような光学系開発に有用な指針を与える。