| 摘要 |
PROBLEM TO BE SOLVED: To provide a waveguide grating element showing no change in the Bragg wavelength even when the element is exposed in a high temperature state for a long time. SOLUTION: In the waveguide grating element 21 having a grating 2 in a waveguide 14 formed in a quartz substrate 11, the quartz substrate 11 is provided with a distortion adjusting mechanism 23 to control the distortion of the grating 2 by connecting both ends of the waveguide 14 in the longitudinal direction with a member having a higher coefficient of linear expansion than that of quartz and by varying the distance between both ends. COPYRIGHT: (C)2003,JPO |
