Patent
Micro-fresnel lens
TLDR
In this article, the height of an uneven pattern of each Fresnel zone is set to a value for giving a phase shift of 2npi (n is a positive integer of >=2).Abstract:
PURPOSE:To facilitate the manufacture and to decrease the chromatic aberration by specifying the height of an uneven pattern in each Fresnel zone. CONSTITUTION:Height of an uneven pattern of each zone is set to a value for giving a phase shift of 2npi (n is a positive integer of >=2). Accordingly, a period of each zone becomes two times, comparing with a conventional Fresnel lens having a value for giving a phase shift whose height is 2pi. That is, even in case of the same numerical aperture NA, the period of each zone becomes (n) times by setting the height of the lens to (n) times. In such a way, the manufacture accuracy is improved, the lens efficiency is raised, and also, the period of the Fresnel zone is lengthened, by which a light beam is curved by a refraction rather than a diffraction effect, and a chromatic aberration caused by a use wavelength variation is decreased.read more
Citations
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Journal ArticleDOI
Low-wavefront aberration and high-temperature stability molded micro Fresnel lens
TL;DR: In this paper, a micro Fresnel lens with a high-diffraction efficiency (>50%), small lens diameter (0.5 mm phi ), short focal length (1 mm), and thin lens fitting was fabricated using a photopolymerization process using a UV-curable resin.
Patent
Electroactive lens with multiple depth diffractive structures
TL;DR: In this article, a diffractive first electroactive lens with multiple depth diffractive structures is described, which can switch from a first power state corresponding to a first optical power to a second power state that differs from the first optical powers.
Proceedings ArticleDOI
Diffractive optical elements: past, present, and future
TL;DR: In this paper, the history of optical elements is traced to get a perspective on their current state-of-the-art, and the important features of this rapidly advancing field are identified so that one does not get lost and can easily stick to one's guns while browsing through the maze of publications.
Patent
Fresnel member having variable sag for multiple wavelength optical system
TL;DR: In this paper, a Fresnel member for an optical system is configured to receive at least reflected light having a first wavelength at a first envelope and reflected light with a second wavelength different from the first one at a second envelope.
Proceedings ArticleDOI
Electron‐beam writing system for holographic optical elements
TL;DR: In this paper, a highly accurate and versatile electron-beam writing system suitable for fabrication of holographic optical elements (HOEs) with arbitrary patterns is developed, and new HOEs with multiple functions are successfully fabricated by the EB system, and their unique applications are introduced.
References
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Patent
Hydrogen storing material
Sakai Takashi,Honda Naojirou +1 more
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