Dai Nippon Printing Co., Ltd.

Nippon Telegraph and Telephone Corporation

Shigekazu Fujimoto

Masaaki Kurihara

Tetsuro Inui

Tetsuro Komukai

The invention relates to a process for the fabrication of an optical fiber-processing phase mask that is reduced in terms of pitch variations on the mask and stitching errors, and provides a process for the fabrication of a chirped type optical fiber-processing phase mask wherein a grating form of grooves provided in one surface of a quartz substrate is configured as an optical fiber-processing grating pattern. At an exposure step, writing data obtained by arranging and compiling a plurality of data for a repetitive groove-and-strip pattern while the pitch of repetition is modulated are used and an electron beam resist is provided on a phase mask blank, so that writing is carried out all over the writing area on said phase mask blank continuously in a vertical direction to said grating form of grooves.

Process for the fabrication of a phase mask for optical fiber processing, optical fiber-processing phase mask, optical fiber with a Bragg grating, and dispersion compensating device using the optical fiber

The present invention provides a substrate-engraving-type chromeless phase-shift mask enabling to adopt a manufacturing method which poses no problem in quality, gives a high operating efficiency, and permits arrangement of characters and symbols, and a manufacturing method thereof. The substrate of the invention has a character/symbol section, on a surface of a transparent substrate, comprising characters and/or symbols engraved in the form of a slit-shaped or lattice-shaped pattern comprising concave grooves only in a prescribed portion corresponding to the characters and/or symbols.

Substrate having character/symbol section and processing method of character/symbol section

The present invention relates to a precision phase mask for forming diffraction grating in optical fiber and optical waveguide, to provide them with nonlinear chirped grating for dispersion compensation use and having low fluctuation or crosstalk in the group delay characteristics. The diffraction grating is formed by means of interference fringe between diffracted lights of different orders, in which the cycle of the diffraction gratingincreases nonlinearly, wherein plurality of diffraction gratings G, G, G. . . having different cycles are assembled on a plane in increasing order of the cycle with the directions of the diffraction gratings directed to the same direction, and assembled in such a manner that, where the cycle of grating changes nonlinearly and discontinuously, the regions having larger rate of change of the cycle contain proportionally more discontinuous phases per unit length.

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Tokyo, Japan

Shigekazu Fujimoto