Abstract: An optical module includes a substrate, an optical device including a surface-emitting or -receiving element mounted on a surface of the substrate with a light-emitting or -receiving portion, an optical fiber disposed parallel to the surface of the substrate and in a longitudinal direction of the substrate, a damming member provided between the optical device and the substrate to extend in a width direction of the substrate and dividing a gap between the optical device and the substrate in the longitudinal direction of the substrate into a first portion and a second portion, and a mirror provided at one side surface of the damming member a tip of the optical fiber. The first portion provided on an opposite side to the optical fiber is filled with an underfill resin, and the second portion provided on a side close to the optical fiber is filled with an optical fiber fixing resin.

Abstract: A connector includes a metallic male terminal housing with a plurality of first joining terminals aligned and accommodated therein, a female terminal housing with a plurality of second joining terminals aligned and accommodated therein, a stacked structure that when the male terminal housing is mated into the female terminal housing, within the male terminal housing, the plural first joining terminals an the plural second joining terminals face each other to form pairs, respectively, at one surface thereof, and the first joining terminals and the second joining terminals are disposed alternately, and an electricity screening plate disposed between the stacked structure and the male terminal housing to cover a side surface of the stacked structure facing the male terminal housing.

Abstract: A waveguide type variable optical attenuator is provided with a substrate for forming a waveguide for optical signal propagation; a waveguide element comprising 2 arm waveguides arranged on the surface of the substrate for constituting a portion of the waveguide and cladding for covering the arm waveguides and the surface of the substrate; and a heater arranged on the surface of the waveguide element for heating the arm waveguides. The 2 arm waveguides are connected thermally.

Abstract: In an optical multiplexer/demultiplexer comprising optical multiplexer/demultiplexer circuits connected in multistage, the optical multiplexer/demultiplexer circuits each have two input ports and two output ports, an optical path, through which input optical signals with predetermined wavelengths are output after multiplexing and demultiplexing, varies depending upon the input port; the optical paths in each of the optical multiplexer/demultiplexer circuits have mutually opposite wavelength dispersion characteristics, and one of the optical paths in a first optical multiplexer/demultiplexer circuit is connected to one of the optical paths, in a second optical multiplexer/demultiplexer circuit, having wavelength dispersion characteristics opposite to the optical path in the first optical multiplexer/demultiplexer circuit.

Abstract: A polymer core optical wave-guide which comprises a substrate, a buffer layer formed on the surface of the substrate made of a SiO.sub.x N.sub.y H.sub.z film of desirable thickness having a refractive index of n.sub.b, an approximately rectangle-shaped core formed on the buffer layer made of a polymer material having a refractive index of n.sub.w (n.sub.w >n.sub.b), a cladding layer covering the surface of the core having a refractive index of n.sub.c (n.sub.c <n.sub.w).