Abstract: A sub-mount for mounting optical components includes a recess for mounting whose side wall is tapered. A light transmission and reception module includes the sub-mount for mounting optical component. The sub-mount is manufactured by forming a master mold of the sub-mount formed with projections and recesses including the recess for mounting of the sub-mount, applying liquid silicone rubber to the mater mold, curing the liquid silicone rubber to produce a mold for duplication, filling the curable material into the mold for duplication, curing the curable material, and separating the cured curable material from the mold for duplication.

Abstract: An optical communication device is provided that includes a flex-rigid substrate including a flexible substrate provided with an electric wiring, and a pair of rigid sections provided on both sides of the flexible substrate. The pair of rigid sections each includes a lamination formed of a conductive circuit and an insulating layer. The optical communication device also includes optical communication means made of a flexible material and having both end faces substantially perpendicular to its optical path of transmitting, and a pair of optical elements having their respective optical functional portions that are mounted on the rigid sections of the flex-rigid substrate. Both end portions of the optical communication means are disposed and fixed on the rigid sections, and at least one of the end faces is optically coupled with at least one of the optical functional portions of the optical elements through a coupling optical element.

Abstract: A waveguide type optical device includes a substrate where a waveguide is formed; a supplemental plate connected on the substrate by using an adhesive; and a groove forming part formed by cutting through the supplemental plate so as to reach the substrate and cut the waveguide, the groove forming part being where a functional thin film is inserted. The supplemental plate and the waveguide adhere to each other or come close to each other in a range not influencing a mode of light.

Abstract: The invention relates to an optical transmitter and/or receiver assembly comprising at least one transmitter component (2) and/or at least one receiver component (3, 4), in addition to a planar optical circuit (5) with at least one integrated waveguide (51). According to the invention, light from the transmitter element (1) is coupled into a waveguide (51) of the planar optical circuit (5) and/or light from the waveguide (51) of the planar optical circuit (5) is uncoupled and guided onto the receiver component (3, 4). The assembly is provided with a lens (14, 15) for optically coupling the waveguide(s) (51) of the planar optical circuit (5) to a fiber-optic that can be fixed to the transmitter and/or receiver assembly (1), said lens (14, 15) being positioned on the planar optical circuit (5).

Abstract: An optically-enabled integrated circuit (IC) package for connecting an electrical circuit board to an optical fiber is presented. The IC package comprises an OSA having a laser which is pre-aligned with the optical fiber. The OSA further comprises a standard electrical interface for the connection to the microchip and a standard optical interface for the connection to the optical fiber. A set of mechanical concepts for connecting optical connectors and cables to integrated circuit packages is also presented and can be applied for any type of optical connector such as single optical fiber ferrules, MT-RJ type optical ferrules and 2-D MT-type optical ferrules.

Abstract: A technique for monitoring optical power in a fiber array unit having a plurality of optical transmission waveguides terminating at an edge thereof for carrying optical signals to and/or from a PLC. A tapping filter is placed within a slit formed in the substrate and interrupting the transmission channels, thereby tapping at least some of the optical power from the channels and directing the tapped optical power toward respective photodetector channels for detection, while allowing other optical power to continue transmission in the at least one channel of the fiber array unit.

Abstract: An opto-electronic board including a printed wiring board with an optical waveguide, a metallic area, and a hole, wherein an abutting face of the optical waveguide and an abutting face of the metallic area form a part of the side face of the hole. The opto-electronic board further comprises an opto-electronic circuit with a bonding pad, wherein the opto-electronic circuit is arranged in the hole and soldered with its bonding pad to the abutting face of the metallic area.

Abstract: A device for coupling an optical fiber includes: a first surface and a second surface, including respective active surface portions; at least one optical fiber positioning element adapted to position at least one point of an optical fiber on a longitudinally median plane of the second surface. The first and second surfaces are movable relative to one another between a first and a second relative position, and, when in the second relative position, cooperate to accommodate a section of the optical fiber therebetween. In this position, the first and second active surface portions cooperate to keep the optical fiber in a predetermined bent condition, particularly adapted to extract light from, or inject light into, the optical fiber. In at least a part of the relative movement from the first to the second relative positions, the first surface rotates with respect to the second surface around a rotational axis oriented transversally with respect to the median plane.

Abstract: A system package using flexible optical waveguides and electrical wires, and a signal processing method thereof are disclosed. Several rigid substrates having highly integrated electronic elements and optical elements mounted thereon can be electrically and optically connected by using flexible substrates that are electrically wired and optically connected. The package can be variously changed when configuring the package by the flexible substrate and the heat dissipation device and the electromagnetic shielding device are installed in the inside of the package, making it possible to solve electromagnetic wave interference problems and thermal problems occurring in the inside of the package.

Abstract: An optical module includes a fiber array, a laser diode array, a photodiode array and a micro-lens array. The fiber array includes optical fibers which are divided to a transmitter group and a receiver group. The laser diode array includes laser diodes which are grouped in a transmitter group. The photodiode array includes photodiodes which are divided to a monitor group and a receiver group. The laser diode array is provided between the fiber array and the photodiode array. The optical fibers of the transmitter group are optically aligned with the laser diodes of the transmitter group, respectively. The micro-lens array is provided between the laser diode array and the photodiode array, and optically aligns the laser diodes of the transmitter group and the optical fibers of the receiver group with the photodiodes of the monitor group and the photodiodes of the receiver group, respectively.

Abstract: In an optical circuit including multi-dimensional photonic crystals, in which the optical circuit has a structure (33), such as a light emitting member or a light receiving member, having a natural resonance frequency, another structure (34) having a natural resonance frequency slightly differing from the natural resonance frequency of the structure (33) is arranged in the vicinity of the structure (33) to control the directivity of localization and propagation of an electromagnetic field, light emission and light reception in a spatial region including the above structures in the multi-dimensional photonic crystals, in order to permit functional operations to be realized.

Abstract: A sample slide, launch system, and method for microscopy having a fiber insertion portal terminating within the sample slide and having a fiber insertion axis such that when an optical fiber is inserted within the fiber insertion portal the optical fiber is positioned so to deliver an EMR to a surface of the sample slide at a desired angle.

Abstract: The present invention discloses an optical device able to luminesce, whereby the optical device comprises, inter alia, a luminescent source that is directly or indirectly mechanically coupled to a low-order mode waveguide, such that light emitting from the luminescent source is optically coupled into the low-order mode waveguide. In embodiments of the invention, the distance D between point sources of the luminescent source and the waveguide is about equal to or smaller than the decay length of the exponential tails of the modes supported by the waveguide, thereby obtaining an optical coupling efficiency of at least 3%. Additional and alternative embodiments are claimed and disclosed.

Abstract: An optical waveguide device includes: a channel waveguide which is positioned at a predetermined height relative to a bottom surface of a substrate; and a slab waveguide having a cross-sectional shape wider than that of the channel waveguide, being positioned at a predetermined height relative to the channel waveguide. Initially, an input end face of the optical waveguide device is vertically scanned with a light beam to achieve optical coupling with the slab waveguide, followed by transversely scanning to achieve optical coupling with the channel waveguide, hence, alignment of an optical axis with a minute channel waveguide can be effected easily and quickly.

Abstract: An optical amplifier is disclosed having a substantially uniform spectral gain. In an exemplary embodiment, the optical amplifier comprises a planar waveguide including a substrate, which includes a region doped with rare earth element. The optical amplifier also comprises an optical fiber including a core doped with the rare earth element. The optical fiber is optically coupled to the planar waveguide.

Abstract: A light receiving device includes a first receiving structure and a second receiving structure. The first receiving structure has a first concentric coupling periodic structure provided in a first surface of a conductive thin film formed on a substrate, a first opening located at a center of the first concentric coupling periodic structure, and a first light receiving section located at an opening end of the first opening. The second receiving structure has a second concentric coupling periodic structure provided in the first surface of the conductive thin film, a second opening located at a center of the second concentric coupling periodic structure, and a second light receiving section located at an opening end of the second opening. The second light receiving section is electrically isolated from the first light receiving section.

Abstract: A light coupler between an optical fiber (6) and a waveguide is made on a semiconductor-on-insulator substrate (1), this substrate (1) comprising a thin layer of semiconducting material in which the waveguide is made. The coupler comprises a light injector (5) and an adiabatic collector (4) made up with an inverted nanotip formed from the thin layer of semiconducting material. The injector (5) is formed on the insulator (3) and has a face (7) for receiving an end of the optical fiber (6). The adiabatic collector (4) has a cross-section which increases from a first end located on the side of said end of the optical fiber (6) right up to a second end which is connected to the waveguide, the injector (5) covering the adiabatic collector (4) and having a rib waveguide shape.

Abstract: An optical coupling component for use in an optical communication connector is provided which comprises a pair of columnar sending side and receiving side optical functional sections and a joint section integrally molded with the optical functional sections and made from the same material as the material of the optically functional sections and having joint regions adjoining the side walls of the optical functional sections, the joint regions of the joint section having a circumferential length along the side walls of the optically functional sections which is equal to or less than a half circumference of the optically functional sections.

Abstract: A hybrid integrated structure of an optical active device and a Planar Lightwave Circuit (PLC) device using an optical fiber array is provided, in which one or more photodiodes are integrated on an upper cladding layer above one or more planar optical waveguides. A section located on a boundary surface between output optical waveguides, that is, an end of the PLC device in the direction of propagation of light, and the input end of an output optical fiber array is ground to be inclined at a predetermined angle with respect to an optical axis. Further, one or more optical fibers and one or more reflection mirrors are alternately arranged, inserted, and disposed in a plurality of V-shaped trenches formed in the output optical fiber array.

Abstract: An optical module where breaking of an optical fiber is avoided to improve ease of handling in the assembly process of the module and mechanical reliability of the module including resistance to impact. The optical module has a PD (3) and an optical fiber (5a) that are mounted on the same substrate (2). A covering section (6) for covering the optical fiber (5a) is placed on a deep trench section (24) having a predetermined depth in the Z2 direction from a V-groove-formed surface where a V-groove for mounting the optical fiber (5a) is formed. The distance h from an end face (3a) of the PD (3) to an end face (24a) of the deep trench section (24) and the distance k from an end face (51a) of the optical fiber (5a) to an end face (6a) of the covering section (6) satisfy the relationship of h>k. The optical fiber (5a) is mounted with both the end face (6a) of the covering section (6) and the end face (24a) of the deep trench section (24) made to be in contact with each other.

Abstract: Methods are disclosed of fabricating an optical assembly. An active optical element is disposed near or on a first surface of a slab of optical material. A passive optical element is formed on a second surface of the slab, with the second surface being substantially parallel to the first surface. An optical axis of the passive optical element is aligned with an optical path between the passive optical element and an active region of the active optical element using a lithographic alignment process.

Abstract: A monolithically integrated optoelectronic subassembly having a waveguide layer stack which is applied on a substrate and has a fiber light-receiving waveguide layer in which at least one photodiode is waveguide-integrated is proposed. A plurality of photodiodes is integrated in the waveguide which is structured laterally and/or vertically in such a manner that there is connected to a coupling waveguide an optical distribution network which in turn feeds the plurality of waveguide-integrated photodiodes in parallel via waveguide parts, which photodiodes are connected electrically in series. All the components are integrated on one chip and conversion of an optical input power into an electrical power is undertaken for current supply purposes. A photodiode can be configured as a signal diode which is supplied from the remaining of the plurality of diodes, as a result of which a self-supplied photodetector is formed.

Abstract: A disclosed optical waveguide holding device is attached onto a printed circuit board of an optical transceiver that performs conversion between an electric signal and an optical signal. The optical waveguide holding device holds an optical waveguide between an external optical fiber and a photoelectric conversion unit attached onto or formed on the printed circuit board. The optical waveguide holding device includes a first connection part configured to optically connect a first end of the optical waveguide to a light receiving/emitting part of the photoelectric conversion unit; a second connection part configured to optically connect a second end of the optical waveguide to the external optical fiber; an optical fiber forming the optical waveguide, disposed between the first end and the second end of the optical waveguide; a first holder configured to hold the optical fiber on a side of the first end; and a second holder configured to hold the optical fiber on a side of the second end.

Abstract: Provided are a photonic-crystal plate that forms an optical waveguide and an optical device assembly using the same, and more particularly, a vertical-type photonic-crystal plate and an optical device assembly configured to be easily integrated with surface-emitting light source devices and surface-receiving light detector devices. The photonic-crystal plate includes a plurality of cylindrical through holes formed in a thickness direction and arranged in a periodic crystal lattice structure. The plate further includes: a main crystal lattice defect that forms a main optical waveguide for passing lights in a direction perpendicular to the photonic-crystal plate; and a sub-crystal lattice defect that forms a sub-optical waveguide for causing light in a specific wavelength band among the lights passing through the main optical waveguide to be optically coupled and passing the coupled light in the direction perpendicular to the photonic-crystal plate.

Abstract: A spot size converter has a first core, a larger second core, and a clad disposed on a substrate. The first core has a rectilinear cross-sectional shape and is embedded in the clad, except at its ends. One of these ends has a sloping surface along which the thickness of the first core tapers gradually to zero. The second core, which has a refractive index intermediate between the refractive indexes of the first core and clad, sits on the clad and covers the sloping end surface of the first core. Light propagates through the first core, then through the second core into an external optical device, or propagates from an external optical device through the second core into the first core. This arrangement provides a spot size converter having an easily manufacturable structure and no polarization dependency.

Abstract: Optical components are flip chip mounted onto a substrate for improved alignment. Each device is fabricated using “build-up” layers above a substrate. Each has an optical confinement region in which optical radiation travels in use, and a bonding surface. The overall depth of the layers above the optical confinement region is closely controlled during fabrication, for instance by the use a “spacer” layer, so that when the devices are subsequently flip chip mounted adjacent one another on a shared substrate by means of their bonding surfaces, they can be passively positioned so that their optical confinement regions abut and optical radiation can be coupled from one to the next in use.

Abstract: An optical cable module has an optical waveguide formed by surrounding a core with a clad layer and a light-receiving/emitting element, installed on a supporting substrate. A light-releasing face of the optical waveguide or a light-incident face to the optical waveguide is aligned so as to face a light-receiving face or a light-emitting face of the light-receiving/emitting element. The optical waveguide is formed into a film shape having flexibility, and provided with a reinforcing member that prevents a deflection from occurring in the optical waveguide. The optical waveguide is placed on a protruding portion from a supporting face of the optical waveguide on the supporting substrate.

Abstract: A photoelectric integrated circuit device, in which photonic devices provided on the same substrate as the LSI are densely arranged along the four sides of the LSI, and characteristic degradation of the laser diode or photo detector due to heat generation can be prevented, furthermore optical wiring is easily performed on the board.

Abstract: The present invention provides a low-cost, high-bandwidth optical laser array where subsequent streams of data are injected in a serial fashion. The invention permits the creation of multiple channels of data on a single optical substrate without the use of costly multiplexer arrays to consolidate various optical signals. Further, the serial array eliminates the need for the parallel alignment of optical data sources, such as lasers, and instead allows for the serial alignment of the optical data sources, resulting in decreased footprint applications.

Abstract: A first optical coupler is configured to direct optical signals from an optical fiber onto one or more first optical channels located on a semiconductor chip, wherein the one or more first optical channels have dimensions that are within a specified tolerance of the dimensions of the optical fiber. One or more second optical couplers are configured to direct the optical signals from the one or more first optical channels to one or more second optical channels located on the semiconductor chip, wherein the one or more second optical channels have a specified sub-micron size.

Abstract: In various embodiments, an illumination structure includes a discrete light source disposed proximate a bottom surface of a waveguide. A top mirror may be disposed above the discrete light source to convert modes of light emitted from the discrete light source into trapped modes, thereby increasing the coupling efficiency of the illumination structure.

Abstract: An optical device is provided to prevent a dicing blade form being clogged when a wafer is cut by means thereof. Further, an optical device is provided to the present invention can prevent unnecessary expansion of a resin used in the optical device. The present invention relates an optical device having a substrate and an optical waveguide layer laminated thereon. The optical waveguide layer has a first lateral surface connected to an optical fiber or an optical fiber array and a second lateral surface not connected to the same. The substrate has a lateral surface disposed on the same side as that of the second lateral surface of the optical waveguide layer. At least a portion of the second lateral surface of the optical waveguide layer is disposed in a plane different from the lateral surface of the substrate so that an exposed area of the substrate is formed between the second lateral surface of the optical waveguide layer and the lateral surface of the substrate.

Abstract: An optical module includes a substrate, one or a plurality of planar optical devices mounted on the substrate, and a waveguide block including one or a plurality of curved waveguides formed on a plane. The waveguide block is mounted on the substrate such that the plane on which the curved waveguides are formed is perpendicular to the substrate and the curved waveguides and an incidence face or an emitting face of the planar optical device are opposed to each other on one end face of the waveguide block. Further, the waveguide block is configured so that an optical fiber can be connected to the other end face of the waveguide block which is orthogonal to the one end face.

Abstract: An optical transceiver using an optical waveguide holding member is disclosed. The optical transceiver includes a printed circuit board and the optical waveguide holding member. Photoelectric conversion elements are formed in the printed circuit board. An optical waveguide including core members is formed in the optical waveguide holding member. The optical waveguide optically connects the photoelectric conversion elements to external optical fibers. An element side lens is formed at one end of the core member so as to face a light receiving and emitting section of the photoelectric conversion element. Flanges are formed on the corresponding side walls of the optical waveguide holding member. The fixed centers of the flanges and optical centers of the element side lenses are arrayed on the same straight line.

Abstract: A segment of optical fiber is engaged with a fiber groove on a device substrate, which positions the fiber segment for optical coupling with an optical component on the substrate. A fiber retainer maintains the fiber segment in engagement with the groove. The fiber retainer may be secured to the substrate with adhesive means. The adhesive means forms at least one retaining member that at least partially fills at least one recessed region formed on the device substrate or on the fiber retainer. That recessed region is spatially separate from the fiber groove and from an area of the fiber retainer engaged with the fiber.

Abstract: An object of the present invention is to provide an optical transmission structural body capable of preferably transmitting an optical signal between an optical wiring and an optical waveguide irrespective of a shape of a portion of the optical wiring, the portion being connected to a core part of the optical waveguide. The optical transmission structural body of the present invention is constituted so that at least an optical wiring and an optical waveguide are connected to each other and an optical signal can be transmitted between a core of the optical wiring and a core part of the optical waveguide, wherein a portion of the optical wiring, the portion being connected to the core part of the optical waveguide, is not specially subjected to a planarization processing or has a surface roughness Ra based on JIS B 0601 of 0.1 ?m or more.

Abstract: An optical-waveguide device mounted on a fixing member having a pair of opposing upright walls and a sub-mount unit including a metallic sub-mount of a rectangular solid shape inserted between the opposing upright walls and a nonmetallic sub-mount of a rectangular solid shape mounted on the metallic sub-mount, and fixed onto a base table. The fixing member and the sub-mount unit as well as the fixing member and the base table are spot-welded together using YAG welding.

Abstract: An optical fiber pigtail and methods of fabricating of the same. The invention also relates to a method of self-alignment of a fiber pigtail and a method of attachment of a fiber pigtail to a surrogate chip.

Abstract: A launch system and method for microscopy having an optical fiber positioned proximate a sample slide with an optical fiber mounting element so as to deliver an EMR from the optical fiber into a first sample slide and to a surface of a second sample slide at a critical angle for total internal reflection at an interface of the surface of the second sample slide and a sample positioned proximate to the surface of the second sample slide.

Abstract: An optical module includes a substrate, one or a plurality of planar optical devices mounted on the substrate, and a waveguide block including one or a plurality of curved waveguides formed on a plane. The waveguide block is mounted on the substrate such that the plane on which the curved waveguides are formed is perpendicular to the substrate and the curved waveguides and an incidence face or an emitting face of the planar optical device are opposed to each other on one end face of the waveguide block. Further, the waveguide block is configured so that an optical fiber can be connected to the other end face of the waveguide block which is orthogonal to the one end face.

Abstract: Optical fibers 301-308 are housed in V-grooves formed on a V-block 20 with end faces 311-318 flush with an end face 22 of the V-block 20. Therefore, when the optical fibers 301-308 are connected to optical waveguides, the V-block 20 suppresses the oscillation of the end faces 311-318 of the optical fibers 301-308. This structure increases the alignment precision and increases the intensity of the optical fibers 301-308.

Abstract: A receiver includes a waveguide defined in a layer of silicon positioned on a base. The waveguide is immobilized relative to the base along the length of the waveguide. The waveguide is unbranched and is a multi-mode waveguide. The receiver also includes a groove configured to receive an optical fiber. The groove is positioned such that when the optical fiber is positioned in the groove the waveguide receives a light signal that exits a facet of the optical fiber. The receiver also includes a light sensor configured to receive the light signal from the waveguide after the light signal is received by the waveguide, is guided through the waveguide, and exits the waveguide. The receiver also includes a tunable optical attenuator configured to attenuate the light signal as the light signal travels along the waveguide. The receiver can be formed on a chip such that the waveguide is the only optical waveguide on the chip.

Abstract: A system and method for using an optical lightguide in a projection display system. A plurality of light sources provides a plurality of colored light to a lightguide. The lightguide may include alternating layers of a relatively high refractive index material and a relatively low refractive index material. In an embodiment, the layers of the lightguide are tapered. In another embodiment, the lightguide includes a light pipe having a lenticular array on the entrance face of the light pipe. Optionally, the light pipe may be tapered. The lightguide provides a line of light to a scanning element, which in turn redirects the light to a spatial light modulator.

Abstract: A sample slide, launch system, and method for microscopy having a fiber insertion portal terminating within the sample slide and having a fiber insertion axis such that when an optical fiber is inserted within the fiber insertion portal the optical fiber is positioned so to deliver an EMR to a surface of the sample slide at a desired angle.

Abstract: An optical device comprises a cantilevered fiber array coupled to a planar lightwave circuit. The cantilevered fiber array comprises a base supporting at least a portion of at least one optical fiber in a fiber guiding channel and a cover bonded to the base and/or the at least one optical fiber, where a terminal end of the at least one optical fiber extends beyond an end of at least one of the base and cover. The planar lightwave circuit comprises a planar waveguide formed on a substrate, the planar waveguide including a waveguide core. The terminal end of the fiber of the cantilevered fiber array is disposed in an alignment groove formed in a portion of the planar lightwave circuit substrate. A transverse channel is formed in the planar lightwave circuit substrate at an optical interface of the waveguide core and the terminal end of the at least one optical fiber.

Abstract: Package substrates for optical die structures are generally described. In one example, an apparatus includes a package substrate having one or more plated through hole (PTH) structures, an optical waveguide coupled with the package substrate, the optical waveguide having one or more input/output (I/O) optical signal pathways to route I/O signals to and from the package substrate, and one or more optical fibers coupled with the optical waveguide, the one or more optical fibers being disposed in the PTH structures to route I/O signals to and from a motherboard.

Abstract: A three-dimensional-optical waveguide is formed by laminating planar substrates such as a plurality of lens substrates and, an isolator substrate and a wavelength division multiplexing filter, the optical substrates at least include a waveguide substrate having a waveguide and a reflecting surface. In the three-dimensional optical waveguide, the planar substrates are positioned by markers integrally formed on at least two of the planar substrates. Light directed into the waveguide is reflected by a reflecting surface and passes through the lens substrates and the isolator substrate.

Abstract: The present invention provides an optical functional circuit where a holographic wave propagation medium is applied and a circuit property is excellent such as small transmission loss and crosstalk. The optical functional circuit where a plurality of circuit elements are formed on a substrate includes the wave propagation medium for converting an optical path of a leakage light so that the leakage light that is not emitted from a predetermined output port of the circuit element is not coupled to a different circuit element. This wave propagation medium is constituted by an optical waveguide that is provided with a clad layer formed on the substrate and a core embedded in the clad layer, and a part of the optical waveguide is formed in accordance with a refractive index distribution which is multiple scattered.

Abstract: An optical apparatus comprises an optical device formed on a device substrate, a first optical waveguide formed on the substrate or on the optical device, and a second, mechanically discrete optical waveguide assembled with the device substrate, optical device, or first optical waveguide. The first optical waveguide is arranged for transferring an optical signal between the optical device and the first optical waveguide. The first and second optical waveguides are arranged, when the second optical waveguide is assembled with the device substrate, optical device, or first optical waveguide, for transferring the optical signal therebetween via optical transverse coupling.

Abstract: An optical integrated circuit with waveguide separation on a substrate includes at least one separating unit, including an optical input/output interface in relation with an external light wave guide, the interface extending in the circuit through an optical guiding input section extended by at least two optical guiding branches mutually spaced apart substantially symmetrically relative to the general direction of the input section. The input section includes as many optical guides as branches, adjacent input section optical guides being substantially rectilinear and mutually parallel, two adjacent optical guides of the input section being separated by an aperture of width D, the refractive index of the opening being lower than that of the optical guides, each input section optical guide having a determined width We1, each branch optical guide exhibiting a width increasing in the direction away from the input section from the width We1 up to a determined width Ws.