OPTICAL WAVEGUIDE TYPE OPTICAL MODULATOR AND PRODUCTION METHOD THEREFOR

摘要

A high-performance optical waveguide type optical modulator which is restrained in buffer layer contamination and dc drift when a signal electric field regulating area is formed in a buffer layer by a lift-off method or etching method, and is excellent in long-term reliability, the optical waveguide type optical modulator (10) comprising a substrate (11) having electrooptic effects, an optical waveguide (12) formed on the front layer of the substrate (11), a traveling wave type signal electrode (13a) and a grounding electrode (13b) formed on the substrate (11), for controlling guided light, a buffer layer (14) formed between the electrode (13) and the optical waveguide (12), and a dielectric layer (15) provided on the entire surface on the electrode (13) side of the buffer layer (14), wherein a signal electric field regulating area (16) having a width larger than the traveling wave type signal electrode (13a) and consisting of a material larger in refractive index than the dielectric layer (15) is formed between the dielectric layer (15) and the electrode (13a).