Abstract: An aluminium gallium indium phosphide (AlGaInP)-based semiconductor laser device is provided. On a main surface of a semiconductor substrate formed of n-type GaAs (gallium arsenide), from the bottom layer, an n-type buffer layer, an n-type cladding layer formed of an AlGaInP-based semiconductor containing silicon (Si) as a dopant, an active layer, a p-type cladding layer formed of an AlGaInP-based semiconductor containing magnesium (Mg) or zinc (Zn) as a dopant, an etching stopper layer, and a p-type contact layer are formed. Here, when an Al composition ratio x of the AlGaInP-based semiconductor is taken as a composition ratio of Al and Ga defined as (AlxGa1?x)0.5P, a composition of the n-type cladding layer is expressed as (AlxnGa1?xn)0.5In0.5P (0.9<xn<1) and a composition of the p-type cladding layer is expressed as (AlxpGa1?xp)0.5In0.5P (0.9<xp?1), and xn and xp satisfy a relationship of xn<xp.

Abstract: Provided is a semiconductor optical device, which has a buried heterostructure structure and is formed in a structure capable of reducing a parasitic capacitance to further improve characteristics thereof, and also provided are an optical transmitter module, an optical transceiver module, and an optical transmission equipment. The semiconductor optical device includes a modulator portion for modulating light input along an emitting direction and radiating the modulated light, the modulator portion including: a mesa-stripe structure, which includes an active layer and extends in the emitting direction; and a buried layer provided adjacent to each side of the mesa-stripe structure, in which a distance between a lower surface of the buried layer and a lower surface of the active layer is 20% or more of a distance between the lower surface and an upper surface of the buried layer.

Abstract: An optical module includes a light-receiving element configured to convert an incident optical signal to an electric signal. The light-receiving element includes a mesa part configured to laminate at least a first semiconductor layer, a light absorption semiconductor layer that absorbs an optical signal entering from a light reception surface, and a second semiconductor layer. The light-receiving element also includes an electrode part disposed on a top of the mesa part and a wiring part that covers a part of a side surface of the mesa part. The optical module includes a lens configured to condense an optical signal from an optical fiber onto the light reception surface. The wiring part is disposed at a position based on an intensity distribution of the optical signal on the light reception surface.

Abstract: A printed circuit board includes a substrate, a signal output circuit formed on the substrate for outputting a clock signal, a shield for covering the signal output circuit, a power supply wiring for connecting the signal output circuit and a power source, and a trap filter provided to the power supply wiring and provided inside the shield, for attenuating a frequency component corresponding to a frequency of clock signal. The trap filter includes a resonance circuit having one portion of the power supply wiring, an inner-layer wiring of the substrate located below the one portion of the power supply wiring, an inner-layer ground wiring of the substrate located below the inner-layer wiring, and a via hole for connecting the one portion of the power supply wiring and the inner-layer wiring.

Abstract: To achieve a size-reduction of an optical module having a circuit that generates a high-frequency clock signal for controlling optical modulation by an optical modulator and to suppress radiation of electromagnetic waves from the optical module. A through-hole via is formed on a multilayer printed circuit board so as to be insulated from a plurality of grounded wiring layers by an anti-pad. A coaxial connector and an intensity modulation control IC that generates a high-frequency clock signal are provided on the multilayer printed circuit board. The high-frequency clock signal is input to the coaxial connector through a micro-strip line formed on the multilayer printed circuit board. An open stub connected to the through-hole via is provided on a wiring layer between a first wiring layer and a second wiring layer among the plurality of wiring layers.

Abstract: Provided is a receiver module, including: a semiconductor light receiving element including an electrode; and a sub-mount including: an electrical wiring joined to the electrode with solder; and a trap region arranged around a joining surface of the electrical wiring, the trap region retaining solder by solder wetting.

Abstract: A wavelength tunable filter and a wavelength tunable laser module are a codirectional coupler type whose characteristics do not vary significantly with a process error. They are structured so as to include a semiconductor substrate which has a first optical waveguide and a second optical waveguide. The first and the second optical waveguides are extended from a first side of the semiconductor substrate to an opposing second side thereof. The first optical waveguide includes a first core layer, which has a planar layout having periodic convexes and concaves, and a pair of electrodes, which vertically sandwich the first core layer. The second optical waveguide includes a second core layer, which has a lower refractive index than the first core layer. Further, a layer having the same composition and film thickness as the second core layer is placed under the first core layer.

Abstract: By forming upper-bank patterns made of Au with a thickness of 1.5 ?m or larger on bank portions, a solder material on a submount and a surface of a conductive layer in an upper part of a ridge portion of a laser chip are separated so as not to be in contact with each other, thereby preventing the stress generated in a bonding portion when bonding the laser chip and the submount from being applied to the ridge portion.

Abstract: An optical module having a flexible substrate having, even after actual manufacturing steps, excellent transmission characteristics of high-frequency signals and an advantage that electromagnetic field radiation is reduced even when it is connected with a package. The flexible substrate used in external connection of the package of the optical module uses a flexible substrate having a coplanar line to which a lead pin is fixedly attached, a grounded coplanar line which is in contact with the coplanar region, and a microstrip line which is in contact with the grounded coplanar line. The flexible substrate has an electrode layout in which an electromagnetic field component of a surface ground line and a signal line is more dominant than an electromagnetic field component of a back-surface ground line and the signal line in a region of the coplanar line adjacent to the grounded coplanar line.

Abstract: An optical module includes an electromagnetic wave absorption member. The electric connection member includes a floating portion which is in a floating state spaced apart from the housing and at a position away from a mounting portion by which the electric connection member is mounted on the housing in the direction opposite to the direction that the optical module is inserted into a cage. At least a portion of the electromagnetic wave absorption member is arranged between the housing and the floating portion. The floating portion is brought into contact with an inner side of the cage so as to establish the electrical connection with the inner side of the cage when the housing is inserted into the cage.

Abstract: An optical device includes a substrate and a first optical waveguide including a mesa. The mesa includes a first lower clad layer portion, a first core layer portion, and a first upper clad layer portion. The first lower clad layer portion, the first core layer portion, and the first upper clad layer portion are disposed in this order from the substrate side. The optical device also includes a first etch stop layer configured to stop etching when the first optical waveguide is formed. The first etch stop layer being laminated over the substrate. The first optical waveguide is laminated on the first etch stop layer.

Abstract: To reduce emission of an unintentional electromagnetic wave even if a frequency of a clock signal being output is high, a printed circuit board (10) includes: a substrate (101); signal output circuits (102 and 103) formed on the substrate (101), for outputting a clock signal; power supply wirings (109 and 110) for connecting the signal output circuits (102 and 103) and a power source; and trap filters (107 and 108) provided to the power supply wirings (109 and 110), for attenuating a frequency component corresponding to a frequency of the clock signal.

Abstract: Provided is an optical receiver module capable of suppressing an increase, which is caused by tolerance of angle occurring at a time of manufacturing, in an amount of reflected return light that enters into an optical fiber while ensuring light-receiving efficiency. The light-receiving element (10) is arranged so that directions of the lines, which extend along the edges contained in a surface of the light-receiving element (10) on a side of the light-receiving-element support member (11), and which intersect with the region surrounded by a straight line corresponding to the incident direction of the light, a straight line corresponding to a direction of the optical axis of the optical fiber (3), and a supporting surface of the light-receiving-element support member (11) for supporting the light-receiving element (10), correspond to the directions different from the directions orthogonal to the incident direction of the light.

Abstract: High performance and high reliability of a semiconductor laser device having a buried-hetero structure are achieved. The semiconductor laser device having a buried-hetero structure is manufactured by burying both sides of a mesa structure by a Ru-doped InGaP wide-gap layer and subsequently by a Ru-doped InGaP graded layer whose composition is graded from InGaP to InP, and then, by a Ru-doped InP layer. By providing the Ru-doped InGaP graded layer between the Ru-doped InGaP wide-gap layer and the Ru-doped InP layer, the Ru-doped InGaP wide-gap layer and the Ru-doped InP layer not lattice-matching with each other can be formed as a buried layer with excellent crystallinity.