Optical receptacle and optical module

An optical receptacle configured to optically couple a photoelectric conversion element and an optical transmission member when the optical receptacle is disposed between the optical transmission member and a photoelectric conversion element package including the photoelectric conversion element, the optical receptacle comprising:

• an optical receptacle main body;
• and
• a fixing member having a cylindrical shape and configured to fix the optical receptacle main body and the photoelectric conversion element package or the optical transmission member,
• wherein the optical receptacle main body includes:
• a first optical surface configured to enter, into the optical receptacle main body, light emitted from the photoelectric conversion element package, or emit, toward the photoelectric conversion element package, light travelled inside the optical receptacle main body;
• a second optical surface configured to emit, toward the optical transmission member, light travelled inside the optical receptacle main body, or enter, into the optical receptacle main body, light emitted from the optical transmission member;
• and
• a groove having an annular shape, and disposed to surround a first central axis of the first optical surface, or disposed to surround a second central axis of the second optical surface;
• and
• wherein the fixing member is configured with a material with a smaller linear expansion coefficient than that of the optical receptacle main body, and is fit to the groove so as to be in contact with at least a part of an inner surface of the groove.