FIXING STRUCTURE OF WAVEGUIDE TYPE ELEMENT

摘要

PROBLEM TO BE SOLVED: To enable a waveguide type element to obtain a stable high frequency characteristic without being affected by the strength of electrical connection with a casing due to the width of a ground electrode. SOLUTION: A notched part 12 is formed in a casing 11 and a modulation electrode and a optical waveguide 2 composed of a signal electrode 3 and the ground electrode 4 are formed in the part of the notched part 12. Here, a substrate 1 is installed and fixed on the casing 11 so that the area where a high frequency electric signal applied on a waveguide type element from the modulation electrode and a light wave guided in the optical waveguide 2 substantially interact each other, is positioned, that is, so that the area of the substantial interaction is not brought in contact with the casing 11.