Abstract: The transmitter module including a semiconductor laser chip, a first carrier, a second carrier, and a lens is disclosed. The first carrier mounts the semiconductor laser chip thereon. The second carrier includes a first surface, a second surface, and a connection surface connecting the first surface with the second surface. The first surface faces in a first direction intersecting an axis direction of the chip to mount the first carrier thereon. The second surface faces in the first direction and is provided at a position farther away from the axis of the chip than the first surface. The lens is fixed to the second surface by an adhesive resin. The connection surface is set back far from a front end of the first carrier adjacent to an emission end of the chip toward a back end of the first carrier opposite to the front end in the axis direction.

Abstract: A light emitting module including a semiconductor light emitting element, a first lens, a second lens, and an optical fiber stub, is disclosed. The first lens collimates light output from the semiconductor light emitting element. The second lens is a meniscus lens and condenses the collimated light to the optical fiber stub. A light entering surface of the second lens has a cross-sectional shape in which an increase rate of a curvature radius is zero or more. A light exiting surface of the second lens includes a first region and a second region. The first region has a cross-sectional shape in which a sign of the increase rate of the curvature radius is positive. The second region surrounds the first region and has a cross-sectional shape in which a sign of the increase rate of the curvature radius is negative.

Abstract: A light emitting module including a semiconductor light emitting element, a first lens, a second lens, and an optical fiber stub, is disclosed. The first lens collimates light output from the semiconductor light emitting element. The second lens is a meniscus lens and condenses the collimated light to the optical fiber stub. A light entering surface of the second lens has a cross-sectional shape in which an increase rate of a curvature radius is zero or more. A light exiting surface of the second lens includes a first region and a second region. The first region has a cross-sectional shape in which a sign of the increase rate of the curvature radius is positive. The second region surrounds the first region and has a cross-sectional shape in which a sign of the increase rate of the curvature radius is negative.

Abstract: The transmitter module including a semiconductor laser chip, a first carrier, a second carrier, and a lens is disclosed. The first carrier mounts the semiconductor laser chip thereon. The second carrier includes a first surface, a second surface, and a connection surface connecting the first surface with the second surface. The first surface faces in a first direction intersecting an axis direction of the chip to mount the first carrier thereon. The second surface faces in the first direction and is provided at a position farther away from the axis of the chip than the first surface. The lens is fixed to the second surface by an adhesive resin. The connection surface is set back far from a front end of the first carrier adjacent to an emission end of the chip toward a back end of the first carrier opposite to the front end in the axis direction.

Abstract: A method of controlling a semiconductor element that includes a semiconductor laser diode (LD), a semiconductor modulator, and a semiconductor optical amplifier (SOA) is disclosed. The LD generates CW light supplied with the first bias current. The semiconductor modulator generates a modulated light by modulating the CW light supplied with a driving signal. The SOA generates an optical signal by amplifying the modulated light supplied with the second bias current. The method first sets the second bias current in a region where the output power of the optical signal shows negative dependence of the second bias current. Then, a temperature of the semiconductor element, the first bias current, and the driving signal are adjusted such that the optical signal shows performance in respective preset ranges.

Abstract: A method of controlling a semiconductor element that includes a semiconductor laser diode (LD), a semiconductor modulator, and a semiconductor optical amplifier (SOA) is disclosed. The LD generates CW light supplied with the first bias current. The semiconductor modulator generates a modulated light by modulating the CW light supplied with a driving signal. The SOA generates an optical signal by amplifying the modulated light supplied with the second bias current. The method first sets the second bias current in a region where the output power of the optical signal shows negative dependence of the second bias current. Then, a temperature of the semiconductor element, the first bias current, and the driving signal are adjusted such that the optical signal shows performance in respective preset ranges.

Abstract: An optical transceiver is disclosed, where the optical transceiver includes an optical subassembly (OSA) with a bottom plate for dissipating heat and connected to an electronic circuit with a flexible printed circuit (FPC). The FPC is soldered with the side electrodes of the OSA as forming a solder fillet in the plane electrode, or the FPC is soldered with the plane electrodes of the OSA as forming the solder fillet in the side electrodes, and leaving a limited room for receiving the curved FPC in peripheries of the OSA.

Abstract: An optical module with some OSAs and a fiber unit is disclosed. The fiber unit includes a stub and a flange. A portion of the stub extrudes from the flange; while, the housing of the module that assembles the OSAs includes a pocket with a diameter substantially equal to or slightly greater than a diameter of the stub. Setting the portion of the stub into the pocket, the fiber unit may be automatically aligned with the OSAs through the housing.

Abstract: An optical transceiver is disclosed, where the optical transceiver includes an optical subassembly (OSA) with a bottom plate for dissipating heat and connected to an electronic circuit with a flexible printed circuit (FPC). The FPC is soldered with the side electrodes of the OSA as forming a solder fillet in the plane electrode, or the FPC is soldered with the plane electrodes of the OSA as forming the solder fillet in the side electrodes, and leaving a limited room for receiving the curved FPC in peripheries of the OSA.

Abstract: An optical module with an arrangement is disclosed in which the module has the LD, the TEC, and the lens with the lens carrier also mounted on the TEC. The signal light from the LD is concentrated by the lens and reflected by the mirror each assembled with the lens carrier mounted on the TEC. The TEC is mounted on the bottom metal that covers the bottom of the ceramic package, the first layer of which is widely cut to set the TEC therein. The FPC is coupled in at least two edges of the first ceramic layer left from the cut.

Abstract: An optical module with some OSAs and a fiber unit is disclosed. The fiber unit includes a stub and a flange. A portion of the stub extrudes from the flange; while, the housing of the module that assembles the OSAs includes a pocket with a diameter substantially equal to or slightly greater than a diameter of the stub. Setting the portion of the stub into the pocket, the fiber unit may be automatically aligned with the OSAs through the housing.

Abstract: A bi-directional optical module with an improved optical crosstalk between the transmitter unit and the receiver unit is disclosed. The optical module provides the LD, the PD, the WDM filter secured with the block, and the package with the co-axial shape. The block provides a slant surface, where the WDM filter is secured thereon, the bottom surface facing the PD mounted on the package, and an aperture connecting the slant surface and the bottom surface. The PD is enclosed within a space formed by the bottom surface and the primary surface, which electrically and optically isolates the PD from the LD.

Abstract: The bi-directional optical module, which installs the receiver and the transmitter within one package, is disclosed with an improved optical crosstalk. The optical module provides a lens, a WDM filter and a photodiode (PD) on an axis of the single mode fiber coupled with the module, while, a laser diode (LD) in a position perpendicular to the optical axis. The WDM filter provides a multi-layered optical film on a primary surface and an edge in a side far from the LD and the (PD) makes an obtuse angle to the primary surface so as to prevent light from the LD and reflected at this edge from entering the PD.

Abstract: An optical module with an arrangement is disclosed in which the module has the LD, the TEC, and the lens with the lens carrier also mounted on the TEC. The signal light from the LD is concentrated by the lens and reflected by the mirror each assembled with the lens carrier mounted on the TEC. The TEC is mounted on the bottom metal that covers the bottom of the ceramic package, the first layer of which is widely cut to set the TEC therein. The FPC is coupled in at least two edges of the first ceramic layer left from the cut.

Abstract: A bi-directional optical subassembly (BOSA) is disclosed. The BOSA of the present invention provides first and second optical devices, a WDM filter and the body that is configured to secure two optical devices and to install the WDM filter. The body has a cylindrical shape with a large bore, a small bore and a joint bore connecting two bores. The WDM filter is attached to the tapered surface of the joint bore.

Abstract: A bi-directional optical subassembly (BOSA) with a unique arrangement to set the WDM filter is disclosed. The BOSA includes the stem and the lens cap. The stem mounts both the LD and the PD. While, the lens cap provides, in addition to the condenser lens, a structure to set the WDM filter in a top center thereof. The WDM filter is set in the lens cap with a present angle to the primary surface of the stem when the lens cap is fixed to the stem. Assembling the lens cap with the stem, the relative optical alignment between the LD, the PD and the WDM filter is performed.

Abstract: An optical module with a ferrule assembly able to be easily produced is disclosed. The ferrule with a tubular shape provides first to third bores. The first bore receives the optical fiber with a sheath, the second bore receives only the glass core of the fiber, which is obtained by removing the sheath, and the third bore has a diameter substantially equal to the outer diameter of the glass core of the fiber. A resin is filled in the gap between the sheath and the third bore, and in the gap between the glass core of the fiber and the second bore. The tip of the glass core is tilted with the axis and protrudes from the end surface of the ferrule.

Abstract: A bi-directional optical module with an arrangement to install WDM filters easily and precisely is disclosed. The optical module of the invention provides two or more optical devices, a filter unit installed with one or more WDM filters, and a coupling unit. One end of the filter unit assembles the coupling unit, while the other end thereof assembled a specific optical device. Rest optical devices are assembled with the filter unit such that their optical axes are perpendicular to the axis connecting the coupling unit with the specific optical device. The WDM filters are set on the inner of the filter bore such that the angle thereof is adjusted by rotating it as coming the edges of the WDM filter in contact with the inner wall.

Abstract: A bi-directional optical module with an improved optical crosstalk between the transmitter unit and the receiver unit is disclosed. The optical module provides the LD, the PD, the WDM filter secured with the block, and the package with the co-axial shape. The block provides a slant surface, where the WDM filter is secured thereon, the bottom surface facing the PD mounted on the package, and an aperture connecting the slant surface and the bottom surface. The PD is enclosed within a space formed by the bottom surface and the primary surface, which electrically and optically isolates the PD from the LD.

Abstract: A bi-directional optical subassembly (BOSA) is disclosed. The BOSA of the present invention provides first and second optical devices, a WDM filter and the body that is configured to secure two optical devices and to install the WDM filter. The body has a cylindrical shape with a large bore, a small bore and a joint bore connecting two bores. The WDM filter is attached to the tapered surface of the joint bore.