Abstract: A metal pattern for a high frequency signal is patterned on a flexile substrate, and the flexile substrate is bent in such a way as to form a substantially right angle at a spot corresponding to an end of the metal pattern for the signal. And an end of the metal pattern is fixedly attached to a lead pin for signaling, attached to a stem, for electrical continuity, so as to be in a posture horizontal with each other. Meanwhile, a part of the lead pins attached to the stem, being in such a state as penetrated through respective holes provided in the flexible substrate, is fixedly attached to a part of metal patterns provided on the flexible substrate so as to ensure electrical continuity therebetween.

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 metal pattern for a high frequency signal is patterned on a flexile substrate, and the flexile substrate is bent in such a way as to form a substantially right angle at a spot corresponding to an end of the metal pattern for the signal. And an end of the metal pattern is fixedly attached to a lead pin for signaling, attached to a stem, for electrical continuity, so as to be in a posture horizontal with each other. Meanwhile, a part of the lead pins attached to the stem, being in such a state as penetrated through respective holes provided in the flexible substrate, is fixedly attached to a part of metal patterns provided on the flexible substrate so as to ensure electrical continuity therebetween.

Abstract: To provide a small-sized and reliable optical module in which a light emitting element and an optical function element respectively remarkably different in a coefficient of thermal expansion are mounted in the same casing, in the invention, the optical function element is mounted on the casing made of first material substantially equal in a coefficient of thermal expansion to the optical function element, a light emitting element unit including the light emitting element (for example, a thermoelectric module over which the light emitting element is mounted) is mounted on a member (base material) made of second material different from the first material and matched with the light emitting element unit in a coefficient of thermal expansion, and the member is, for example, embedded in the bottom of the casing.

Abstract: The present invention provides a structure that makes high-frequency transmission possible in an optical module and in the optical transmission apparatus using the module. The invention has means that excludes, from the service band of the optical module, frequency of the standing waves occurring at connection between the first high-frequency signal line substrate and second high-frequency signal line substrate in the optical module.

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 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: The present invention provides an optical modulator module comprising: a chip carrier; a semiconductor optical modulator for modulating light based on an electronic signal; a strip conductor electrically connected to the semiconductor optical modulator; a first resistor electrically connected to the semiconductor optical modulator; and a second resistor electrically connected in series to the first resistor; wherein the semiconductor optical modulator, the strip conductor, and the first and second resistors are disposed on the chip carrier; and wherein the frequency characteristics of the optical modulator module is adjusted by selecting to short or not to short both ends of the first resistor by use of a wire as necessary.

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: The present invention provides a compact, highly reliable optical module in which a light-emitting element and optical modulator element that differ from each other in thermal expansion coefficient are mounted in one casing. In the optical module having a differential thermal expansion coefficient less than 5×10?6 [1/K] between the light-emitting element and the casing, and a differential thermal expansion coefficient of at least 5×10?6 [1/K] between the optical modulator element and the casing, a section at which the optical modulator element and the casing are fixed is equal to or less than 10 mm wide in the direction of an optical axis.

Abstract: To provide a small-sized and reliable optical module in which a light emitting element and an optical function element respectively remarkably different in a coefficient of thermal expansion are mounted in the same casing, in the invention, the optical function element is mounted on the casing made of first material substantially equal in a coefficient of thermal expansion to the optical function element, a light emitting element unit including the light emitting element (for example, a thermoelectric module over which the light emitting element is mounted) is mounted on a member (base material) made of second material different from the first material and matched with the light emitting element unit in a coefficient of thermal expansion, and the member is, for example, embedded in the bottom of the casing.

Abstract: There is provided an optical module in which electrical wirings in a module package are simplified without increasing a manufacturing cost. A light emitting element is mounted on a substrate having electrical wirings therein. In the substrate, electrodes connected to the electrical wirings are formed at a side where the light emitting element is mounted. The light emitting element and the electrodes of one ends of the wirings are wire-bonded to each other and one ends of leads and the electrodes the other ends of the wirings are wire-bonded to each other.

Abstract: The present invention provides a compact, highly reliable optical module in which a light-emitting element and optical modulator element that differ from each other in thermal expansion coefficient are mounted in one casing. In the optical module having a differential thermal expansion coefficient less than 5×10?6 [1/K] between the light-emitting element and the casing, and a differential thermal expansion coefficient of at least 5×10?6 [1/K] between the optical modulator element and the casing, a section at which the optical modulator element and the casing are fixed is equal to or less than 10 mm wide in the direction of an optical axis.

Abstract: The present invention provides an optical modulator module comprising: a chip carrier; a semiconductor optical modulator for modulating light based on an electronic signal; a strip conductor electrically connected to the semiconductor optical modulator; a first resistor electrically connected to the semiconductor optical modulator; and a second resistor electrically connected in series to the first resistor; wherein the semiconductor optical modulator, the strip conductor, and the first and second resistors are disposed on the chip carrier; and wherein the frequency characteristics of the optical modulator module is adjusted by selecting to short or not to short both ends of the first resistor by use of a wire as necessary.

Abstract: The present invention provides a structure that makes high-frequency transmission possible in an optical module and in the optical transmission apparatus using the module. The invention has means that excludes, from the service band of the optical module, frequency of the standing waves occurring at connection between the first high-frequency signal line substrate and second high-frequency signal line substrate in the optical module.

Abstract: A variable optical attenuator VOA and a gain-clamped semiconductor optical amplifier GC-SOA are combined as an optical preamplifier. The variable optical attenuator is controlled so that a desired optical power is sent to the gain-clamped semiconductor optical amplifier or so that a desired optical power is sent to a photoelectric conversion stage. A optical power monitor is provided to compare a monitored value with a target value, and a variable optical attenuator control circuit controls the variable optical attenuator so that the deviation from the target value approximates 0.

Abstract: In an optical module including an optical element and a semiconductor IC for driving it in a case, a metal stem 35 on which an optical element 10 is mounted is provided with a wiring plate 11, a semiconductor IC 30 for electrically driving the optical element 10, and the wiring plate 11 are connected with each other by wires 16, and further the wiring plate 11 and the optical element 10 are connected with each other by the wires 16. The optical communication module having excellent high frequency characteristics is formed that shuts out influence of heat from the semiconductor IC upon the optical element and causes no interference between the semiconductor IC and optical connecting lenses.

Abstract: An optical module capable of connecting signal lines to an external substrate easily without causing any degradation of the transmission characteristic is disclosed. The optical module comprises an optical element mounting block having an optical element mounting section and an optical fiber guide, and a wiring lead integrated resin substrate having a ferrule holding section, an optical element mounting block housing section, and wiring leads, where at least a part of the wiring leads are provided by signal lines in a coplanar guide structure entirely formed on the wiring lead integrated resin substrate such that a characteristic impedance does not change when the wiring leads are electrically connected to external wirings.

Abstract: An optical module capable of connecting signal lines to an external substrate easily without causing any degradation of the transmission characteristic is disclosed. The optical module comprises an optical element mounting block having an optical element mounting section and an optical fiber guide, and a wiring lead integrated resin substrate having a ferrule holding section, an optical element mounting block housing section, and wiring leads, where at least a part of the wiring leads are provided by signal lines in a coplanar guide structure entirely formed on the wiring lead integrated resin substrate such that a characteristic impedance does not change when the wiring leads are electrically connected to external wirings.

Abstract: An optical functional device includes a semiconductor substrate, an optical functional layer provided on said semiconductor substrate and selected from the group consisting of a light emitting layer, a light absorbing layer, and an optical waveguide layer. The optical functional layer has a multi-quantum well layer. Preferably, the semiconductor substrate is a nonplanar semiconductor substrate having a ridge and two grooves adjacent said ridge, said ridge having a ridge width of from 1 to 10 .mu.m, a ridge height of from 1 .mu.m to 5 .mu.m, and a gap distance of from 1 .mu.m to 10 .mu.m. Such an optical functional device can be fabricated by growing, on a nonplanar semiconductor substrate having a specified dimension of the ridge, a strained multi-quantum well layer by metalorganic vapor phase epitaxy. Integrated optical device or circuit preferably includes an optical functional device on the nonplanar semiconductor substrate of a specified range of ridge shape factors.