Optical transmission module, endoscope, and method for manufacturing optical transmission module

An optical transmission module comprising:

• a first optical device for transmitting or receiving a first optical signal;
• a second optical device for transmitting or receiving a second optical signal;
• an optical fiber for guiding a third optical signal in which the first optical signal and the second optical signal are coupled;
• and
• an optical waveguide substrate having an optical waveguide made of first resin, in which the optical waveguide has a first reflective face with a tilt angle of 45 degrees relative to a first end face, and a second end face is optically coupled with an optical path of the optical fiber,
• wherein a groove formed on the optical waveguide substrate is provided with the optical fiber and a prism having a second reflective face with a tilt angle of 45 degrees through which the first optical signal transmits,
• an optical path of the optical waveguide is optically coupled with an optical path of the first optical device orthogonal to the optical path of the optical waveguide via the first reflective face,
• the optical path of the optical fiber is optically coupled with an optical path of the second optical device orthogonal to the optical path of the optical fiber via the second reflective face,
• the second end face of the optical waveguide is exposed on a first wall face of the groove, and a face of a positioning member made of the first resin is exposed on a second wall face of the groove, and
• a first side face of the prism contacts the first wall face of the groove, and a second side face contacts the second wall face of the groove.