It is an object of the invention to supply an optical communication device and
an optical communication module that are provided with a substrate, a vertical
waveguide that is formed in the substrate and that is for transmitting light in
a thickness direction of the substrate, a horizontal waveguide that is formed in
the substrate and that is for transmitting light in a planar direction of the substrate,
and a light bending portion for optically coupling the vertical waveguide and the
horizontal waveguide. The substrate is a laminated body including a first substrate
in whose surface a groove is formed and in which a reflective mirror is disposed
on at least one end of the groove, and a second substrate layered to the surface
of the first substrate in which the groove is formed and in which a through hole
located in opposition to the portion of the groove in which the reflective mirror
is disposed is formed. The horizontal waveguide includes a cavity formed by the
groove and a reflective film that covers the wall surfaces of the cavity, and transmits
light through its cavity. The vertical waveguide include a cavity formed by the
through hole and a reflective film that covers the wall surfaces of the cavity,
and transmits light through its cavity. The light bending portion includes the
reflective mirror, and due to reflection at the surface of the reflective mirror,
the light transmission direction is changed from the thickness direction to the
planar direction of the substrate or from the planar direction to the thickness
direction of the substrate.