Abstract: A semiconductor optical modulator, a Mach-Zehnder optical modulator employing the same, and a method of manufacturing a semiconductor optical modulator that are suitable for high-speed baseband communication are provided. An optical waveguide core layer is formed in such a manner that it alternately crosses micro optical modulator elements and gap regions, which are formed by placing electrically insulating material at predetermined intervals on an electrically conductive substrate. The core layer is connected to a signal electrode portion via a conductive semiconductor portion in each micro optical modulator element. A ground electrode is connected to the core layer via the conductive substrate. Further, the signal electrode portions are connected in a series to form a signal electrode by means of in-between metal wirings. Conductive semiconductor material is located between the core layer and the electrodes. In the gap regions, the core layer is sandwiched between insulating semiconductor layers.

Abstract: An optical semiconductor element and an optical element having an optical coupling facet are disposed on a support surface of a platform. The optical element is optically coupled to the optical semiconductor element at the optical coupling facet. A protective member covers the optical semiconductor element and is disposed at least in a light transmission area in a space between the semiconductor element and the optical coupling facet of the optical element. The protective member is made of gel acrylic modification resin. An optical semiconductor module having a sufficient moisture resistance and being suitable for low cost is provided.

Abstract: A plurality of semiconductor devices are disposed in a line on the surface of a supporting substrate. Each semiconductor device is adapted to generate an electric signal depending on the intensity of incident light. Adjacent semiconductor devices are optically coupled by an interconnecting optical waveguide so that light can pass through the semiconductor device one by one in a direction from a first stage closest to an input end to a last stage. An electric signal transmission line is formed of a pair of conductors connected to the semiconductor devices so that the electric signal generated by the semiconductor devices can propagate. One conductor of the pair of conductors of the electric signal transmission line is formed so as to extend in the air above the supporting substrate between adjacent semiconductor devices.

Abstract: An optical semiconductor element and an optical element having an optical coupling facet are disposed on a support surface of a platform. The optical element is optically coupled to the optical semiconductor element at the optical coupling facet. A protective member covers the optical semiconductor element and is disposed at least in a light transmission area in a space between the semiconductor element and the optical coupling facet of the optical element. The protective member is made of gel acrylic modification resin. An optical semiconductor module having a sufficient moisture resistance and being suitable for low cost is provided.

Abstract: An optical semiconductor element and an optical element having an optical coupling facet are disposed on a support surface of a platform. The optical element is optically coupled to the optical semiconductor element at the optical coupling facet. A protective member covers the optical semiconductor element and is disposed at least in a light transmission area in a space between the semiconductor element and the optical coupling facet of the optical element. The protective member is made of gel acrylic modification resin. An optical semiconductor module having a sufficient moisture resistance and being suitable for low cost is provided.

Abstract: An optical semiconductor device of the present invention is provided with a core layer having a quantum well layer in that film thickness gets thinner from a inner region to an end portion in an optical waveguide region.

Abstract: A method of forming waveguides, refractive index distributions and optical couplings automatically by light incidence, and devices obtained thereby. A non-linear optical material which has excellent properties of a large degree of freedom for an optical circuit substrate composition, etc. is used for optical circuit devices and optical circuit substrates. A photoelectric device containing an organic conjugated polymer film is deposited on a substrate by vapor deposition polymerization as at least one function layer. An optical network is provided with optical wiring for exchanging signals between processing elements selected from electronic elements, electronic apparatuses, electrooptical elements and electrooptical apparatuses.

Abstract: An optical semiconductor device circuit including a MI-DFB-LD capable of minimizing an extension in the wavelength of the output light in order to improve transmission speed and distance. The optical device circuit includes a semiconductor laser diode; an optical modulator for modulating output light of the semiconductor laser diode; a resistive element which is connected to the laser diode and which operates as a resistor at a high frequency; common connection substrate connected to the semiconductor laser diode and to the optical modulator; impedance element or signal reflection element connected to the common connection substrate; and ground connected to the impedance element or the signal reflection element.

Abstract: An optical semiconductor device of the present invention is provided with a core layer having a quantum well layer in that film thickness gets thinner from a inner region to an end portion in an optical waveguide region.

Abstract: Embedded layers having a high resistance or an inverse conductivity with respect to a ridge structure are formed on either side of a ridge structure which is formed to correspond to an light emission region of a laser diode. The embedded layers confines a current in the ridge structure and moderates light-confinement performance in the ridge structure at an emitting end of the laser diode.

Abstract: A group III-V compound semiconductor laser of a 1 .mu.m band having an excellent conversion efficiency and a high characteristic temperature. The semiconductor laser can emit light in a 1.3 .mu.m band or a 1.55 .mu.m, and has a laser structure including an active layer For emitting light, guide layers sandwiching the active layer and having a band gap larger than the active layer, and clad layers embracing the guide layers and having a band gap larger than the guide layers. The lattice constants of the guide layers and clad layers are larger than a1 by 0.5% or more and smaller than a2 by 0.5% or more, where a1 represents the lattice constant of GaAs and a2 is the lattice constant of InP.

Abstract: A semiconductor laser including a stripe-shaped active layer, a clad region, and a diffraction grating. The stripe-shaped active layer has a thickness in a first direction, has a first energy gap, and extends in a second direction orthogonal to the first direction. The clad region surrounds the stripe-shaped active layer, and has a second energy band gap greater than the first energy band gap. The diffraction grating is provided in parallel with and adjacent to, the stripe-shaped active layer. The stripe-shaped active layer has a first portion with a first light propagation constant and with a first dimension in a third direction orthogonal to the first and second directions, and has a second portion with a second light propagation constant and with a second dimension in the third direction. The first dimension and the second dimension are different from each other. The second portion has a length L in the second direction. The stripe-shaped active layer satisfies the condition that a product of .DELTA..beta.