CHIRP GRATING FORMING DEVICE

摘要

PURPOSE: To provide a chirp grating forming device capable of easily forming a chirp grating in an optical waveguide with satisfactory mass-productivity. CONSTITUTION: A chirp grating forming device 100 is provided with a light source 10, a plate type phase grating 20 in which the light from the light source 10 is made incident and a block 30 where two diffracted lights 22, 24 emitted from the plate type phase grating 20 are made incident into the interior. The block 30 has reflection surfaces 33, 34 respectively reflecting the diffracted lights 22, 24 and has at least one reflection surface having a curved surface. A chirp grating is formed in an optical waveguide by irradiating a photosensitive optical waveguide 40 with interference fringes generated by making diffracted lights which are reflected at these reflection surfaces interfere each other.