Abstract: A submount which has a mounting surface on which three or more semiconductor lasers are arranged in a first direction, and includes a heat generator configured to increase the temperatures of the three or more semiconductor lasers, in which, where the heat generator generates heat, a first heat of the heat absorbed by a first semiconductor laser of the three or more semiconductor lasers disposed at one end along the first direction is larger than a second heat of the heat absorbed by a second semiconductor laser of the three or more semiconductor lasers disposed to be adjacent to the first semiconductor laser on the mounting surface.

Abstract: A submount which has a mounting surface on which three or more semiconductor lasers are arranged in a first direction, and includes a heat generator configured to increase the temperatures of the three or more semiconductor lasers, in which, where the heat generator generates heat, a first heat of the heat absorbed by a first semiconductor laser of the three or more semiconductor lasers disposed at one end along the first direction is larger than a second heat of the heat absorbed by a second semiconductor laser of the three or more semiconductor lasers disposed to be adjacent to the first semiconductor laser on the mounting surface.

Abstract: Provided is a butt-jointed (BJ) semiconductor integrated optical device having a high manufacturing yield. A semiconductor integrated optical device, which is configured such that, on a semiconductor substrate, a first semiconductor optical element including an active layer and a second semiconductor optical element including a waveguide layer are butt-jointed to each other with their optical axes being aligned with each other, includes: a semiconductor regrowth layer including at least one of a diffraction grating layer or an etching stop layer, which is formed by one epitaxial growth across an entire surface above the active layer and the waveguide layer; and a cladding layer formed above the semiconductor regrowth layer.

Abstract: Provided is a butt-jointed (BJ) semiconductor integrated optical device having a high manufacturing yield. A semiconductor integrated optical device, which is configured such that, on a semiconductor substrate, a first semiconductor optical element including an active layer and a second semiconductor optical element including a waveguide layer are butt-jointed to each other with their optical axes being aligned with each other, includes: a semiconductor regrowth layer including at least one of a diffraction grating layer or an etching stop layer, which is formed by one epitaxial growth across an entire surface above the active layer and the waveguide layer; and a cladding layer formed above the semiconductor regrowth layer.

Abstract: To suppress occurrence of axial hole burning in a phase shift portion of a diffraction grating, provided is a semiconductor optical device including: a diffraction grating layer including a diffraction grating and a phase shift portion; and an optical waveguide layer including an active layer that has a gain with respect to an emission wavelength and an optical waveguide region that has no gain with respect to the emission wavelength. The optical waveguide region is formed at least on the lower side of the phase shift portion.

Abstract: A wavelength tunable laser module for DWDM is used, in which a single electroabsorption modulator integrated laser is mounted and an oscillation wavelength is made tunable by temperature control. Driving conditions of a laser and a modulator are determined such that they have approximately the same modulation and transmission characteristics in a temperature control range. Such an electroabsorption modulator integrated laser is used and the driving conditions are incorporated, thereby a small, inexpensive wavelength tunable optical transmitter can be provided.

Abstract: A chip carrier includes a metal-coated portion formed on a front surface of a substrate and to be mounted a device, and a rear surface of the substrate being coated with a metal, in which a metal-coated portion is formed on a side surface of the substrate and the metal-coated portion on the front surface of substrate is connected with the metal-coated portion on the rear surface by the metal-coated portion formed on the side surface of the substrate, thereby maintaining frequency characteristics of the optical semiconductor device.

Abstract: A semiconductor optical device has a semiconductor laser portion and a modulator portion which have different mesa structures. The mesa structure of the semiconductor laser portion is a ridge waveguide structure which has air around the mesa. The mesa structure of the modulator portion is a planarized ridge waveguide structure which has an organic insulator buried around the mesa.

Abstract: This invention provides an optical transmitter module and an optical module using an EA modulator capable of realizing stable ACER regardless of operating temperature without using a control mechanism for maintaining temperature of the EA modulator constant. In the EA modulator, optical waveguides formed of a multi-layered film are formed on a substrate, an electrical signal is applied to the optical waveguides in a direction vertical to the substrate, and the input light absorption amount is changed to control the amount of output light. Also, a plurality of p-side electrodes electrically separated from each other for applying an electrical signal to the active layer optical waveguides are arranged on optical axes of active layer optical waveguides. The length of optical waveguides to which the electrical signal is applied is changed by controlling the number of p-side electrodes to which the electrical signal is applied in accordance with temperature.

Abstract: A high frequency substrate, on which a high frequency substrate transmission line for connecting a chip carrier transmission line and a package substrate transmission line is formed, is mounted while being inclined with respect to a package, so that each distance between the transmission lines can be reduced. Thereby, the lengths of wires for connecting the transmission lines can be reduced so as to improve frequency characteristics of an optical modulator module.

Abstract: A semiconductor optical device has a semiconductor laser portion and a modulator portion which have different mesa structures. The mesa structure of the semiconductor laser portion is a ridge waveguide structure which has air around the mesa. The mesa structure of the modulator portion is a planarized ridge waveguide structure which has an organic insulator buried around the mesa.

Abstract: A wavelength tunable laser module for DWDM is used, in which a single electroabsorption modulator integrated laser is mounted and an oscillation wavelength is made tunable by temperature control. Driving conditions of a laser and a modulator are determined such that they have approximately the same modulation and transmission characteristics in a temperature control range. Such an electroabsorption modulator integrated laser is used and the driving conditions are incorporated, thereby a small, inexpensive wavelength tunable optical transmitter can be provided.

Abstract: Even for a driving impedance of 25 ?, high transmission waveform quality of an optical transmission module is maintained using an optical modulator element designed for a driving impedance of 50 ?. The above can be achieved by adopting an optical module 100 that includes an input electrode for electrical signals, an optical modulator element for modulating laser light using the electrical signals, a termination resistance element, a first bonding wire for connecting the input electrode and the optical modulator element, a second bonding wire for connecting the optical modulator element and the termination resistance element, and a third bonding wire for connecting the input electrode and the termination resistance element.

Abstract: A high frequency substrate, on which a high frequency substrate transmission line for connecting a chip carrier transmission line and a package substrate transmission line is formed, is mounted while being inclined with respect to a package, so that each distance between the transmission lines can be reduced. Thereby, the lengths of wires for connecting the transmission lines can be reduced so as to improve frequency characteristics of an optical modulator module.

Abstract: A chip carrier includes a metal-coated portion formed on a front surface of a substrate and to be mounted a device, and a rear surface of the substrate being coated with a metal, in which a metal-coated portion is formed on a side surface of the substrate and the metal-coated portion on the front surface of substrate is connected with the metal-coated portion on the rear surface by the metal-coated portion formed on the side surface of the substrate, thereby maintaining frequency characteristics of the optical semiconductor device.

Abstract: A chip carrier includes a metal-coated portion formed on a front surface of a substrate and to be mounted a device, and a rear surface of the substrate being coated with a metal, in which a metal-coated portion is formed on a side surface of the substrate and the metal-coated portion on the front surface of substrate is connected with the metal-coated portion on the rear surface by the metal-coated portion formed on the side surface of the substrate, thereby maintaining frequency characteristics of the optical semiconductor device.

Abstract: Even for a driving impedance of 25 ?, high transmission waveform quality of an optical transmission module is maintained using an optical modulator element designed for a driving impedance of 50 ?. The above can be achieved by adopting an optical module 100 that includes an input electrode for electrical signals, an optical modulator element for modulating laser light using the electrical signals, a termination resistance element, a first bonding wire for connecting the input electrode and the optical modulator element, a second bonding wire for connecting the optical modulator element and the termination resistance element, and a third bonding wire for connecting the input electrode and the termination resistance element.

Abstract: This invention provides an optical transmitter module and an optical module using an EA modulator capable of realizing stable ACER regardless of operating temperature without using a control mechanism for maintaining temperature of the EA modulator constant. In the EA modulator, optical waveguides formed of a multi-layered film are formed on a substrate, an electrical signal is applied to the optical waveguides in a direction vertical to the substrate, and the input light absorption amount is changed to control the amount of output light. Also, a plurality of p-side electrodes electrically separated from each other for applying an electrical signal to the active layer optical waveguides are arranged on optical axes of active layer optical waveguides. The length of optical waveguides to which the electrical signal is applied is changed by controlling the number of p-side electrodes to which the electrical signal is applied in accordance with temperature.

Abstract: A chip carrier includes a metal-coated portion formed on a front surface of a substrate and to be mounted a device, and a rear surface of the substrate being coated with a metal, in which a metal-coated portion is formed on a side surface of the substrate and the metal-coated portion on the front surface of substrate is connected with the metal-coated portion on the rear surface by the metal-coated portion formed on the side surface of the substrate, thereby maintaining frequency characteristics of the optical semiconductor device.

Abstract: For achieving a transmission light source having different transmission properties or characteristics, i.e., the &agr; parameters, depending upon application thereof, in a light emission element of semiconductor EA modulator integrated type being constructed with a light emission portion for lasing with a single vertical mode and a plurality of EA modulators, wherein an absorption edge wavelength under the condition of applying no bias thereto, in the semiconductor multiple-quantum-well structure owned by the modulator which is near to an emission side of the light emission portion, is to be equal or longer than the absorption edge wavelength owned by the modulator positioned far from the emission side of the light emission portion.