Abstract: A spark plug includes a metal shell, an insulator, a center electrode, and a ground electrode. At least one of the center electrode and the ground electrode includes a projection having a columnar shape. The projection projects toward the other of the center electrode and the ground electrode and forms the discharge gap. A portion of a side surface of the projection has a recess. A melted portion is formed by melting the noble metal tip and an electrode base material. The recess is formed in the melted portion. When D is a depth of the recess from a side surface of the noble metal tip and R is a diameter of the noble metal tip, 0.05 mm?D?0.3×R is satisfied.

Abstract: An optical source that implements a wavelength tunable laser diode (t-LD) and a Mach-Zehnder (MZ) modulator within a single package is disclosed. The optical source, which outputs a modulated signal beam and a local beam of a continuous wave (CW), accompanies a control circuit mounted on several circuit boards. Only one of the circuit boards is rigidly mounted on the housing of the optical source.

Abstract: A pluggable optical transceiver that enhances the heat dissipation function is disclosed. The optical transceiver provides the MPO connector that receives an external MT ferrule, the assembly substrate that installs a semiconductor optical device, a lens block that bends the optical axis of the semiconductor optical device by about 90°, the circuit board electrically connected to the assembly substrate, the inner fiber optically couples the WO connector with the lens block, and the top and bottom housings that installs the MPO connector, the assembly substrate, the circuit board, and the inner fiber therein. The bottom housing mounts the circuit board, while, the assembly substrate is thermally and physically in contact to the top housing through a thermal grease.

Abstract: A mechanism for an optical transceiver to latch with and release from a cage is disclosed. The mechanism includes a bail rotatable around an axis and a slider linearly movable between the latching position and the releasing position. The rotation of bail is independent of the liner motion of the slider.

Abstract: A pluggable optical transceiver is disclosed. The optical transceiver provides a pull-tab assembled with a body of the transceiver. The pull-tab comprises a pair of arms and a handle. The arms in an end portion thereof each provides a leg set in a guide formed in the body. Sliding the pull-tab to disengage the optical transceiver from the cage, the leg is slid within the guide to push the end portion of the arm outwardly. The handle provides in an end thereof a bar including a slope. The optical fiber pulled out from the optical connector set in the optical receptacle of the transceiver rides on the slope even when the transceiver is set in the cage by the upside-down arrangement.

Abstract: A pluggable optical transceiver is disclosed. The optical transceiver provides a pull-tab assembled with a body of the transceiver. The pull-tab comprises a pair of arms and a handle. The arms in an end portion thereof each provides a leg set in a guide formed in the body. Sliding the pull-tab to disengage the optical transceiver from the cage, the leg is slid within the guide to push the end portion of the arm outwardly. The handle provides in an end thereof a bar including a slope. The optical fiber pulled out from the optical connector set in the optical receptacle of the transceiver rides on the slope even when the transceiver is set in the cage by the upside-down arrangement.

Abstract: A pluggable optical transceiver with the CFP type and the MT ferrule is disclosed. The optical transceiver provides in a rear of the optical receptacle a mechanism to push frontward the MT ferrule set in the optical receptacle and to shield the inside of the optical transceiver. Inner fibers connecting the MT ferrule with another MT ferrule assembled with optical devices pass the mechanism, which may be a metal plate with the elastic function and/or a coil spring combined with a holder to hold the MT ferrule.

Abstract: A pluggable optical transceiver with the CFP type and the MT ferrule is disclosed. The optical transceiver provides in a rear of the optical receptacle a mechanism to push frontward the MT ferrule set in the optical receptacle and to shield the inside of the optical transceiver. Inner fibers connecting the MT ferrule with another MT ferrule assembled with optical devices pass the mechanism, which may be a metal plate with the elastic function and/or a coil spring combined with a holder to hold the MT ferrule.

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 transceiver that attenuates the EMI radiation leaked therefrom is disclosed. The optical transceiver includes a top cover and the bottom base to form a cavity into which a TOSA, a ROSA, and a circuit are set. At least one of the top cover and the bottom base provides a combed structure in a rear portion of the optical transceiver, where the combed structure has a plurality of T-shaped fins to attenuate the EMI radiation.

Abstract: A pluggable optical transceiver is disclosed. The optical transceiver provides a pull-tab assembled with a body of the transceiver. The pull-tab comprises a pair of arms and a handle. The arms in an end portion thereof each provides a leg set in a guide formed in the body. Sliding the pull-tab to disengage the optical transceiver from the cage, the leg is slid within the guide to push the end portion of the arm outwardly. The handle provides in an end thereof a bar including a slope. The optical fiber pulled out from the optical connector set in the optical receptacle of the transceiver rides on the slope even when the transceiver is set in the cage by the upside-down arrangement.

Abstract: An optical transceiver having a effective heat conducting path from the TOSA to the metal housing is disclosed. The TOSA has a bottom member, on which a heat generating device such as TEC is mounted, extending to a direction perpendicular to the longitudinal axis of the metal housing. The optical transceiver further includes a block movably in contact with the bottom member of the TOSA and the inner surface of the metal housing to establish the effective heat conducting path from the TOSA to the metal housing.

Abstract: A pluggable optical transceiver is disclosed. The optical transceiver includes a resin made optical receptacle to receive an external connector, a housing that provides an area for setting the optical receptacle, and an electrically conductive sheet put between the rear of the optical receptacle and the wall forming the area. The rear wall of the optical receptacle provides a step for receiving a flange of a sleeve assembly set in the optical receptacle.

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: A heat transferring mechanism of an optical transceiver is disclosed. The optical transceiver includes a metal cover, a OSA that generate heat, and a heat conductor. The OSA has the heat transferring surface extending to a direction intersecting, or substantially in perpendicular, to the longitudinal direction of the optical transceiver. The heat conductor, which is formed only by cutting and bending of metal plate, includes a contact plate and the transfer plate in thermally contact to a heat transferring surface of the OSA and an inner surface of the metal cover to form an effective heat transferring path from the OSA to the cover.

Abstract: An optical transceiver disclosed provides an OSA, a circuit board, a housing, a holder and a electrically conductive nonwoven material. The housing provides the first space that provides an optical receptacle and receives an external optical connector, and the second space within which the circuit board is installed. Two spaces are divided by a partition wall with a cut to pass the sleeve of the OSA. The nonwoven material, which is put between the partition wall and the holder, fills a gap formed between the sleeve and the cut.

Abstract: An optical transceiver having a effective heat conducting path from the TOSA to the metal housing is disclosed. The TOSA has a bottom member, on which a heat generating device such as TEC is mounted, extending to a direction perpendicular to the longitudinal axis of the metal housing. The optical transceiver further includes a block movably in contact with the bottom member of the TOSA and the inner surface of the metal housing to establish the effective heat conducting path from the TOSA to the metal housing.

Abstract: A heat transferring mechanism of an optical transceiver is disclosed. The optical transceiver includes a metal cover, a OSA that generate heat, and a heat conductor. The OSA has the heat transferring surface extending to a direction intersecting, or substantially in perpendicular, to the longitudinal direction of the optical transceiver. The heat conductor, which is formed only by cutting and bending of metal plate, includes a contact plate and the transfer plate in thermally contact to a heat transferring surface of the OSA and an inner surface of the metal cover to form an effective heat transferring path from the OSA to the cover.

Abstract: A pluggable optical transceiver is disclosed. The transceiver comprises a plurality of OSAs, an optical member and a plurality of inner fibers to couple the optical member with OSAs. The inner fibers each provides an inner connector to couple with one of OSAs. The housing, which installs the OSAs, the optical member and the inner fiber, is made of metal and has a grooves into which the inner fibers is set so as to arrange them orderly.

Abstract: A pluggable optical transceiver is disclosed. The transceiver comprises a plurality of OSAs, an optical member and a plurality of inner fibers to couple the optical member with OSAs. The inner fibers each provides an inner connector to couple with one of OSAs. The housing, which installs the OSAs, the optical member and the inner fiber, is made of metal and has a grooves into which the inner fibers is set so as to arrange them orderly.