A first optical communication device 1 comprises: a laser light source 3 that emits a communication light CL; and a transmission-use optical fiber 11 that is disposed underwater WA and that has a light incidence end 14 on which the communication light CL is caused to be incident and that causes the communication light CL having been incident on the light incidence end 14 to propagate toward a front end 15. The transmission-use optical fiber 11 comprises: a core part 21 that causes the communication light CL to propagate from the light incidence end 14 toward the front end 15; and a clad part 23 that covers the core part 21 and that causes at least part of the communication light CL propagating along the core part 21 to go out from the side surface of the transmission-use optical fiber 11.
展开▼
