| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To suppress generation of Bragg-reflected beams, even if the shielding performance of light is enhanced by increasing the variation in the refractive index of a core in an optical filter constituted of a tilt grating. <P>SOLUTION: The tilt angleθof the tilt grating 3 in the optical filter 100 is such that the Bragg-reflected quantity of the optical filter 100 becomes a minimum, in comparison to the Bragg-reflected quantities of other optical filters which is provided with a core on which the tilt grating is formed under a second exposure condition in which only the exposure quantity of ultraviolet light is increased and which is reduced, with reference to a first exposure condition adopted for forming the tilt grating 3 in the optical filter 100. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
