To provide an optical device that prevents variation characteristics of a center wavelength of reflection at a diffraction grating with respect to voltage applied to a piezoelectric element from shifting due to temperature variation.
The optical device 1 is provided with a U shaped base 2, an optical fiber 4 with a diffraction grating part 8 formed thereon and a piezoelectric element 6 (PZT (lead zirconate titanate) ceramics). The U shaped base 2 is provided with a base part 2a and a pair of arm parts 2b, 2c extending from the base part 2a and is composed of a material having a thermal expansion coefficient larger than that of the piezoelectric element 6 (an aluminum alloy, etc.). A voltage application means 10 to apply voltage is connected to the piezoelectric element 6 of which the degree of displacement varies correspondingly to magnitude of the voltage applied by the voltage application means 10. The piezoelectric element 6 is formed into a rod shape and is fixed to the U shaped base 2 so as to be connected nearly at the middle of the pair of the arm parts 2b, 2c. The optical fiber 4 is fixed to end parts of the arm parts 2b, 2c of the U shaped base 2 so as to stride over the part of the optical fiber where the diffraction grating part 8 is formed.
SAITO KAZUTO
SANO TOMOMI
TAKAHASHI KENICHIRO
