Invention Grant
- Patent Title: Diffractive optical element
- Patent Title (中): 衍射光学元件
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Application No.: US10532044Application Date: 2004-02-05
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Publication No.: US07440188B2Publication Date: 2008-10-21
- Inventor: Keiji Fuse
- Applicant: Keiji Fuse
- Applicant Address: JP Osaka
- Assignee: Sumitomo Electric Industries, Ltd.
- Current Assignee: Sumitomo Electric Industries, Ltd.
- Current Assignee Address: JP Osaka
- Agency: McDermott Will & Emery LLP
- Priority: JP2003-029244 20030206
- International Application: PCT/JP2004/001230 WO 20040205
- International Announcement: WO2004/077115 WO 20040910
- Main IPC: G02B5/18
- IPC: G02B5/18

Abstract:
A conventional diffractive optical element (DOE), which consists of repetition of a unit pattern , has an advantage of applicability of the Fast Fourier Transform algorithm to calculate diffraction beam spots intensities on lattice points on an image plane. But, the conventional DOE has a drawback of impossibility of diffracting a laser beam off the lattice points. This invention designs a DOE by giving arbitrary complex amplitude transmittance {tmn} to every pixel (m, n), calculating actual Fourier transform from {tmn} to intensity W(α, β), and obtaining intensity of a diffraction beam directing in any α and β direction. Since α, β are not necessary to be on lattice points, the FFT is of no use. Angular resolutions U and V satisfy inequalities U
Public/Granted literature
- US20060013277A1 Diffractive optical element and laser machining apparatus using same Public/Granted day:2006-01-19
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