The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 11, 2005
Filed:
Mar. 31, 2003
Ken Hashimoto, Yokohama, JP;
Akira Inoue, Yokohama, JP;
Masaki Ohmura, Yokohama, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
In a method of making a diffraction grating device, an optical waveguide is irradiated, by way of a phase grating mask, with refractive index modulation inducing light so as to form a diffraction grating in the predetermined region. This method comprises (1) a step of measuring a diffraction efficiency distribution of the phase grating mask; and (2) a step of longitudinally scanning the optical waveguide with the refractive index modulation inducing light by way of the phase grating mask and irradiating the optical waveguide with the refractive index modulation inducing light so as to modulate a refractive index of the predetermined region. Upon scanning with the refractive index modulation inducing light, longitudinal relative positions of the phase grating mask and optical waveguide are changed according to the diffraction efficiency distribution of the phase grating mask.