Abstract: The optical module includes an optical separating element. The optical separating element includes a birefringent material and has a first face and a second face. The first face is configured to receive a signal light and a LO light. The signal light includes a first polarized light and a second polarized light. The first polarized light travels from the first face to the second face in a first direction and is emitted from a first emission spot on the second face. The second polarized light travels from the first face to the second face in a second direction and is emitted from a second emission spot on the second face. The LO light travels from the first face to the second face in the first direction and is emitted from a LO light emission spot which is located between the first emission spot and the second emission spot.

Abstract: An optical module that provides a semiconductor modulator, an input lens system and first and second output lens systems, and two monitor photodiodes is disclosed. The semiconductor modulator provides an input port, first and second output ports, and two monitor ports in one side thereof. The input port and the first and second output ports face the input lens system and the first and second lens systems, respectively. The two monitor ports face the two monitor photodiodes, respectively. The first and second output ports are symmetrically disposed with respect to the input port in the one side. The two monitor ports are disposed in respective outer sides of the first and second output ports and symmetrically with respect to the input port.

Abstract: An ammonia production plant and an ammonia production method having high energy saving and environmental friendliness are provided.

Abstract: An optical module that includes a shell, an optical fiber, a coupling portion, and a ferrule is disclosed. The shell installs an optical device, for instance, a multi-mode interference (MMI) device therein. The optical fiber in a tip thereof is optically coupled with the optical device within the shell. The coupling portion has a cylindrical shape with a bore having an axis and secures the optical fiber, where the coupling portion is attached to the shell. The ferrule, which is secured in the coupling portion, has a pillared shape with a diameter that is slightly smaller than a diameter of the bore of the coupling portion. The ferrule has a groove that receives and secures the optical fiber therein. The filler fills the groove and fixes the optical fiber in the groove.

Abstract: An optical connector according to an embodiment includes: a receptacle in a cylindrical shape, the receptacle being configured to hold a first optical fiber, the receptacle having a flat surface on an outer surface thereof, the flat surface being parallel with a first optical axis of the first optical fiber; a plug in a cylindrical shape, the plug being configured to hold an optical fiber, the plug having a flat surface on an outer surface thereof, the second flat surface being parallel with a second optical axis of the optical fiber; and a clip member having a contact surface the flat surface with the flat surface, the clip member being configured to press the receptacle and the plug against each other for optically coupling the first optical fiber to the second optical fiber.

Abstract: An optical module including a source assembly is disclosed. The source assembly provides a semiconductor optical device, a wiring substrate, and a bridge substrate. The semiconductor optical device includes an electrode and a pad that receives a driving signal therethrough. The wiring substrate, which is arranged side by side with respect to the semiconductor optical device, provides a signal line and a ground line surrounding the signal line. The bridge substrate includes a signal line and a ground line surrounding the signal line. A feature of the optical module is that the bridge substrate is placed on the semiconductor optical device and the wiring substrate such that a transmission line thereof faces the semiconductor optical device and the wiring substrate, and one end of the signal line thereof is connected with the pad of the semiconductor optical device through a post, and another end of the signal line thereof is connected with an end of the signal line in the wiring substrate through another post.

Abstract: Provided are a non-hydrocarbon gas separation device and the like capable of increasing a discharge pressure of a non-hydrocarbon gas to a downstream side while preventing an increase in size of equipment. In the non-hydrocarbon gas separation device, a first separation module (2a) and a second separation module (2b) connected to each other in series are each configured to separate a non-hydrocarbon from a natural gas through use of a separation membrane (20). The non-hydrocarbon gas having been separated from the natural gas is discharged to each of discharge lines (202) and (204). At this time, a pressure of the first separation module (2a) on a discharge line (202) side is higher than a pressure of the second separation module (2b) on a discharge line (204) or (202) side.

Abstract: Provided is a non-hydrocarbon gas separation device or the like capable of separating a non-hydrocarbon gas from a natural gas containing a heavy hydrocarbon. The non-hydrocarbon gas separation device is configured to separate a non-hydrocarbon gas from a natural gas. The natural gas containing a heavy hydrocarbon, the heavy hydrocarbon having 5 or more carbon atoms, is supplied to a separation module (2). The natural gas having been separated from the non-hydrocarbon gas is allowed to outflow from the separation module (2), and the non-hydrocarbon gas having been separated from the natural gas is discharged from the separation module (2). An inorganic membrane (20), which is housed in the separation module (2), and is made of an inorganic material is configured to allow the non-hydrocarbon gas contained in the natural gas to permeate therethrough to a discharge side, and to allow the natural gas having been separated from the non-hydrocarbon gas to flow to an outflow side.

Abstract: The receiver including a package, first and second optical fibers, a capillary, and an array lens is disclosed. The first fiber has a first edge coupling to a MMI device by propagating a signal beam. The second fiber has a second edge coupling to the MMI device by propagating a local beam. The array lens has first and second lenses. The first lens converts the signal beam into a collimating beam, and the second lens converts the local beam into a collimating beam. The capillary has an edge opposite to the array lens, and the edge has a first region including the first edge and a second region including the second edge. The first edge is slanted to a first axis, and the second edge is slanted to a second axis, and a direction of the first edge and a direction of the second edge are different each other.

Abstract: A coherent receiver comprising: a signal port receiving the signal light that has two polarization components at right angles each other; a polarization dependent beam splitter (PBS) that splits the signal light into two portions depending on the polarizations contained in the signal light; a beam splitter (BS) that splits the local light into two portions; a multi-mode interference (MMI) device that interferes between one of the two portions of the signal light and one of the two portions of the local light; optical components provided between the PBS and the MMI device; and wherein the PBS splitting a first wavelength range of the signal light and a second wavelength range outside the first wavelength range.

Abstract: An optical module includes an LD that emits laser beam; a carrier that mounts the LD and thermistor thereon; a photodetector detecting the laser beam output from the LD; a TEC that mounts the carrier and the photodetector thereon; a chassis having a box-shape demarcated by walls that form a space for enclosing the LD, the TEC, and the photodetector therein, wherein at least of the walls has a window, and the thermistor arranged between the LD and the photodetector.

Abstract: The receiver including a package, first and second optical fibers, a capillary, and an array lens is disclosed. The first fiber has a first edge coupling to a MMI device by propagating a signal beam. The second fiber has a second edge coupling to the MMI device by propagating a local beam. The array lens has first and second lenses. The first lens converts the signal beam into a collimating beam, and the second lens converts the local beam into a collimating beam. The capillary has an edge opposite to the array lens, and the edge has a first region including the first edge and a second region including the second edge. The first edge is slanted to a first axis, and the second edge is slanted to a second axis, and a direction of the first edge and a direction of the second edge are different each other.

Abstract: An optical module is disclosed. The optical module comprises an optical semiconductor element having a first optical axis thereof, an optical receptacle optically coupling with the semiconductor element and having a second optical axis thereof, a box-shaped housing having a bottom and a side wall built in an end of the bottom, and a beam shifter provided in the side wall. The housing encloses the optical semiconductor element therein but extracts the optical receptacle. The side wall of the housing demarcates the optical semiconductor element from the optical receptacle. The beam shifter aligns the first optical axis with the second optical axis.

Abstract: An optical module with a laser diode (LD) without any temperature control and an optical fiber that is coupled with the LD through the two lens system is disclosed. The two lens system first converts laser beam into collimated beam and second concentrates the collimated beam onto the optical fiber. A beam splitter is disposed between the lenses and splits the collimated beam toward a photodiode (PD). The PD, which receives the split collimated beam in a back surface thereof, provides an anti-reflection film in the back surface. The anti-reflection film eliminates multi reflections occurred within the PD.

Abstract: An optical module that includes at least one semiconductor optical device, a carrier, a housing, and eutectic alloy that fixes the carrier to the housing is disclosed. The carrier mounts a component that couples with the semiconductor optical device. The housing, which includes a side wall made of ceramics and a base made of metal to form a space that encloses the semiconductor optical device, the carrier, and the component therein. The carrier provides a room facing the base and the side wall, where the room receives excess eutectic alloy oozing out from a gap between the carrier and the base.

Abstract: An optical module that includes a shell, an optical fiber, a coupling portion, and a ferrule is disclosed. The shell installs an optical device, for instance, a multi-mode interference (MMI) device therein. The optical fiber in a tip thereof is optically coupled with the optical device within the shell. The coupling portion has a cylindrical shape with a bore having an axis and secures the optical fiber, where the coupling portion is attached to the shell. The ferrule, which is secured in the coupling portion, has a pillared shape with a diameter that is slightly smaller than a diameter of the bore of the coupling portion. The ferrule has a groove that receives and secures the optical fiber therein. The filler fills the groove and fixes the optical fiber in the groove.

Abstract: An optical module with a laser diode (LD) without any temperature control and an optical fiber that is coupled with the LD through the two lens system is disclosed. The two lens system first converts laser beam into collimated beam and second concentrates the collimated beam onto the optical fiber. A beam splitter is disposed between the lenses and splits the collimated beam toward a photodiode (PD). The PD, which receives the split collimated beam in a back surface thereof, provides an anti-reflection film in the back surface. The anti-reflection film eliminates multi reflections occurred within the PD.

Abstract: An optical module and a method of assembling the optical module are disclosed. The optical module comprises a laser unit, a modulator unit, and a detector unit mounted on respective thermo-electric coolers (TECs). The modulator unit, which is arranged on an optical axis of the first output port from which a modulated beam is output, modulates the continuous wave (CW) beam output from the laser unit. On the other hand, the laser unit and the detector unit are arranged on another optical axis of the second output port from which another CW beam is output. The method of assembling the optical module first aligns one of the first combination of the laser unit and the modulator unit with the first output port and the second combination of the laser unit and the detector unit, and then aligns another of the first combination and the second combination.

Abstract: A flexible printed circuit board includes: a board having a top surface and a back surface; a signal line on the top surface; a ground line on the back surface and overlapping with the signal line; a first signal terminal extending along a first direction in the top surface, the first signal terminal including a first via-hole and electrically connected with the signal line; a first ground terminal next to the first signal terminal along a second direction intersecting the first direction on the top surface, the first ground terminal including a second via-hole electrically connected with the ground line; and a second ground terminal next to the first signal terminal in a side opposite to the first ground terminal along the second direction on the top surface, the second ground terminal including a third via-hole electrically connected with the ground line.

Abstract: An optical receiver module that receives a wavelength multiplexed light and a process to assemble the optical receiver module are disclosed. The optical receiver module provides a coupling unit to collimate the wavelength multiplexed light and a device unit that installs an optical de-multiplexer and photodiode elements within a housing. The front wall of the housing through which the wavelength multiplexed light passes is polished in a right angle with respect to the bottom of the housing.