An optical waveguide monitor equipped with an output light monitor having
a decreased restriction in the dimensions and form thereof, a high
reliability and a low production cost includes an optical waveguide
element (having a plurality of surface waveguide portions, a connecting
portion for converging and connecting the surface waveguide portions and
an output light-outputting waveguide portion connected to the connecting
portion each formed on a dielectric substrate plate; an output light
optical fiber connected to an output end of the output light-outputting
waveguide portion, a reinforcing capillary for reinforcing a connection
between the optical waveguide element and the output light optical fiber
and a monitoring light receiving means, wherein the reinforcing capillary
has a hole or groove for containing and supporting the output light
optical fiber therein, a connecting face thereof bonded to an output end
face of the substrate, and a terminal surface opposite to the connecting
face, to thereby enable at least one member of the reinforcing capillary
per se and a monitoring light optical fiber located within the capillary
to receive the monitoring light outputted from the optical waveguide
element, to transmit it therethrough and to output it to the outside of
the capillary, and the monitoring light receiving means is located in a
position suitable to receive the monitoring light outputted to the
outside of the reinforcing capillary and has a photoelectric conversion
element.