Abstract: An optical fiber for an optical fiber sensor and a chemical sensor using the same are disclosed. The optical fiber includes a core area, and a suspended cladding area formed around the core area and having at least one cladding hole. The core area has at least one core hole for reducing an effective refractive index of the core area. The optical fiber and the chemical sensor using the same may have improved measurement sensitivity by increasing an evanescent field fraction of existing suspended core fibers.

Abstract: Configurations are disclosed for presenting virtual reality and augmented reality experiences to users. The system may comprise an image-generating source to provide one or more frames of image data in a time-sequential manner, a light modulator configured to transmit light associated with the one or more frames of image data, a substrate to direct image information to a user's eye, wherein the substrate houses a plurality of reflectors, a first reflector of the plurality of reflectors to reflect transmitted light associated with a first frame of image data at a first angle to the user's eye, and a second reflector to reflect transmitted light associated with a second frame of the image data at a second angle to the user's eye.

Abstract: Planar lightwave circuits with a polymer coupling waveguide optically coupling a planar waveguide over a first region of a substrate to an optical component, such as a laser, affixed to a second region of the substrate. The coupling waveguide may be formed from a polymer layer applied over the planar waveguide and optical component such that any misalignment between the two may be accommodated by patterning the polymer into a waveguide having a first end aligned to an end of the planar waveguide and a second end aligned to an edge of the optical component. In embodiments, the polymer is photo-definable, such as a negative resist, and may be patterned through direct laser writing. In embodiments, the optical component is a thin film affixed to the substrate through micro-transfer printing. In other embodiments, the optical component is a semiconductor chip affixed to the substrate by flip-chip bonding.

Abstract: Disclosed herein is an optical fiber assembly comprising a launching fiber having a receiving end and a transmitting end; an illuminating fiber having a receiving end and a transmitting end; where the receiving end of the launching fiber is operative to receive light from a light source and the transmitting end of the launching fiber is operative to transmit light to the receiving end of the illuminating fiber; where the launching fiber contacts the illuminating fiber in a manner so as to be offset from a center of a cross-sectional area of the illuminating fiber; and where the launching fiber has a diameter that is ? to ½ of a diameter of the illuminating fiber; and a lens that is operative to contact the transmitting end of the illuminating fiber.

Abstract: The present disclosure relates to semiconductor structures and, more particularly, to silicon waveguide devices in integrated photonics and methods of manufacture. The integrated photonics structure includes: a localized region of negative thermal expansion (NTE) coefficient material formed within a trench; at least one photonics or CMOS component contacting with the negative thermal expansion (NTE) coefficient material; and cladding material formed above the at least one photonics or CMOS component.

Abstract: A compact bidirectional optical transceiver module is provided that has a bidirectional optical subassembly (BOSA) that includes a stamped metal optic that folds the optical pathway, alignment features that enable the optoelectronic components of the electrical subassembly (ESA) to be precisely aligned with the BOSA in all dimensions, and features that reduce the capacitance of the driver circuitry to improve signal integrity and widen the eye opening.

Abstract: Inverted 45° semiconductor mirrors as vertical optical couplers for PIC chips, particularly optical receivers and transmitters. An inverted 45° semiconductor mirror functions to couple light between a plane in the PIC chip defined by thin film layers and a direction normal to a top surface of the PIC chip where it may be generated or collected by an off-chip component, such as a wire terminal. In an exemplary embodiment, a (110) plane of a cubic crystalline semiconductor may provide a 45° facet inverted relative to a (100) surface of the semiconductor from which light is to be emitted. In further embodiments, a (110) plane may be exposed by undercutting a device layer of a semiconductor on insulator (SOI) substrate. Alternatively, a pre-etched substrate surface may be bonded to a handling wafer, thinned, and then utilized for PIC waveguide formation.

Abstract: There is provided a display device including (I) an eyeglass-shaped frame configured to be mounted on a head of an observer, and (II) an image display device attached to the frame. The image display device includes (A) an image forming device, and (B) an optical device on which light output from the image forming device is incident, in which the light is guided, and from which the light is output. A dimmer configured to adjust an amount of external light incident from outside is installed on a side opposite to a side on which the image forming device of the optical device is disposed. A light shielding member configured to shield incidence of external light on the optical device is disposed in a region of the optical device on which light output from the image forming device is incident.

Abstract: An imaging system can include of a plurality of pairs of lenslets and a respective plurality of two-dimensional arrays of photonic waveguides arranged in a respective plurality of photonic integrated circuits. Each waveguide can collect light in an airy-disk-size bin to cover a full field of view of the lenslet. Light from each pair of respective waveguides from each pair of lenslets can be demultiplexed into wavelength bins and combined with appropriate phase shifts to enable a measurement of the complex visibility. The complex visibilities from all of the measurements then can be processed to form an image.

Abstract: An optical transceiver using a modulator biased to a non-linear region of the modulator's power transfer function can extend the possible transmission distance of intensity modulated direct detection (IMDD) n-level pulse amplitude modulated (PAM-n) signals. A non-linear look-up-table may compensate for non-linear characteristics of the modulator. An adaptive decision threshold look-up-table may be used to provide adaptive decision levels at the receiver.

Abstract: A multiplexed optical communication system comprising a carrier optical fiber, a plurality of launching light sources, and a matching plurality of multiplexer/demultiplexers and photodetectors is described and claimed. Optical communication channel separation by Spatial Domain Multiplexing (SDM), Optical Angular Momentum (OAM) multiplexing, and Wavelength Division Multiplexing (WDM) is used in combination to achieve significant increase in optical communication channel bandwidth over the prior art. The launching light sources may be positioned such that the light beams are incident on the receiving end of the carrier optical fiber at desired angles including complementary angles. Crosstalk between optical communication channels is minimal. The communication bandwidth of a TDM system may be increased by an order of magnitude due the layered WDM/SDM/OAM data multiplexing of the invention.

Abstract: A laser unit includes: multi-mode semiconductor lasers configured to output laser lights in multi-mode; an optical multiplexer configured to multiplex and output the laser lights; a multi-mode optical fiber configured to connect the multi-mode semiconductor lasers to the optical multiplexer, and including a core portion, a cladding portion, and a coated portion; a first bending portion formed to the multi-mode optical fiber and bent with a predetermined bending length and at a predetermined first bending radius; a radiation portion formed outside the coated portion at the first bending portion, and configured to radiate heat of the multi-mode optical fiber; and a second bending portion formed to the multi-mode optical fiber between the first bending portion and the optical multiplexer and bent at a predetermined second bending radius, wherein increase in a temperature at the second bending portion is restrained by radiation from the radiation portion.

Abstract: This light receptacle comprises: first optical surfaces on which light beams emitted from light emitting elements are respectively caused to be incident; second optical surfaces which emit the light beams incident on first optical surfaces respectively toward the end faces of light transmission bodies; a third optical surface which reflects the light beams incident on the first optical surfaces toward the second optical surfaces; and recesses which are formed in the surface on which second optical surfaces are arranged. The distance between the centers of two adjacent first optical surfaces before mold release and the distance between the centers of two adjacent second optical surfaces before mold release during injection molding are shorter than the distance between the optical axes of light beams emitted from two adjacent light emitting elements that are arranged so as to face each other.

Abstract: An apparatus for packaging a photonic transceiver. The apparatus includes a case having a base member, two partial side members, and a lid member to provide a spatial volume with an opening at a back end of the base member. Additionally, the apparatus includes a PCB installed inside the spatial volume over the base member with a pluggable connector at the back end. The apparatus includes one or more optical transmitting devices being mounted upside-down via a flex circuit board bended 180 degrees inward to a backside of the PCB and including a built-in TEC module in contact with the lid member. Furthermore, the apparatus includes a silicon photonics chip including a fiber-to-silicon attachment module, mounted on the PCB and coupled to a modulation driver module and a trans-impedance-amplifier module. Moreover, the apparatus includes an optical input port and output port being back connected to the fiber-to-silicon attachment module.

Abstract: The apparatus includes a case having a base member, two partial side members, and a lid member to provide a spatial volume with an opening at a back end of the base member. Additionally, the apparatus includes a PCB installed inside the spatial volume over the base member with a pluggable connector at the back end. The apparatus includes one or more optical transmitting devices in transmit-optical-sub-assembly package, each being mounted upside-down on the PCB and including a built-in TEC module in contact with the lid member and a laser output port aiming toward the back end. Furthermore, the apparatus includes a silicon photonics chip including a fiber-to-silicon attachment module, mounted on the PCB and coupled to a modulation driver module and a trans-impedance-amplifier module. Moreover, the apparatus includes an optical input port and output port being back connected to the fiber-to-silicon attachment module.

Abstract: Provided is a downsized connector for a multicore fiber and a plurality of single-mode fibers which can simplify the core alignment process between the fibers. The optical fiber connector includes a mount substrate, a multicore fiber including a plurality of cores arrayed in the same plane, a first sub-substrate configured to fix an end part of the multicore fiber, and to be bonded on the mount substrate, a plurality of single-mode fibers including at least the same number of fibers as the plurality of cores of the multicore fiber, and a second sub-substrate configured to fix end parts of the plurality of single-mode fibers, and to be bonded on the mount substrate. A relative position between the first sub-substrate and the second sub-substrate is determined, so that the plurality of cores of the multicore fiber and the plurality of single-mode fibers of the same number as the plurality of cores are optically coupled, respectively.

Abstract: The present invention discloses a wavelength selective switch and a method for controlling a spatial phase modulator in a wavelength selective switch.

Abstract: A wavelength selection switch can decrease the amount of increase in size and cost of a node device by integrating and sharing the constituent components of a plurality of wavelength selection switches or optical components mounted in a node. The wavelength selection switch has: at least one input port that inputs light; at least one output port that receives light from the input port; at least one light-collecting element that alters the beam shape of the light entering from the input port; at least one scattering element that scatters the light entering from the input port into each wavelength; at least one wavefront control element that causes light of each wavelength scattered by the scattering element to be reflected to the output port for each wavelength.

Abstract: An optical combiner (25), comprising a bundle of input fibers (24) spliced to an output fiber (26), the output fiber having a cladding and at least one high-index portion within the cladding, such that the high index portion has a diameter substantially equal to or less than the outer diameter of the input fiber bundle at the splice point.

Abstract: Example devices are optical dividers including: a first optical coupler; a second optical coupler; and a third optical coupler. The devices also comprise a first optical fiber integrated in the first optical coupler, the first optical fiber coupled to an optical combiner, and a second optical fiber integrated in the first optical coupler and in the second optical coupler, the second optical fiber coupled to the optical combiner. The devices further comprise a third optical fiber integrated in the second optical coupler and in the third optical coupler, the third optical fiber coupled to the optical combiner. The optical combiner includes: a first output coupler; a second output coupler; and the optical combiner couples a subset of the first through third optical fibers to the first output coupler; and the optical combiner couples a subset of the first through third optical fibers to the second output coupler.

Abstract: A virtual reality system includes a playground defined within a real world space to have a predetermined area in which a user is movable, a head mounted device surrounds both eyes displaying an image of a virtual space formed corresponding to real objects in the playground, a sensor attached to a predetermined location in the playground, the head mounted device or body of the user sensing an actual location or motion of the user in the playground. A control unit calculates a location and direction of the user in the playground according to a signal from the sensor, and displays an image on the head mounted device of the virtual space, observed at the location and in the facing direction of the user. When the user wearing the head mounted device actually moves in the playground, a feeling of moving in the virtual space is given to the user.

Abstract: As kilowatt class fiber laser and amplifier systems become more in demand, there are ongoing efforts to improve optical fiber laser and amplifier designs to maximize efficiency and further increase the capacity of these high-energy optical fiber lasers and amplifiers. The present disclosure provides a fiber laser or amplifier system configured to efficiently and conveniently generate and couple high numerical aperture and high-energy pump light into a fiber laser or amplifier system.

Abstract: An optical element includes a lens component and a reflecting mirror. The lens component includes first, second and third planes disposed to surround and parallel to a reference axis. The first plane is formed with first, second, third, and fourth collimating units. The second plane is formed with fifth and sixth collimating units. The lens component further includes fourth, fifth, sixth and seventh planes cooperatively defining a groove unit extending along and indented toward the reference axis from the third plane. The fourth and sixth planes extend obliquely relative to said first plane. The reflecting mirror is disposed on the third plane to cover the groove unit and has at least one reflecting plane facing the fourth, fifth, sixth and seventh planes.

Abstract: The invention relates to an optical scattering element suitable for dispersing or scattering light transmitted by optical device by Mie scattering. The optical scattering element comprises a phase-separated or porous borosilicate glass having dispersed phase particles with a particle size of 200 to 500 nanometers or pores with a size of 200 to 500 nanometers, at a number density of 108 to 1012 mm?3. The optical scattering element can be prepared by subjecting a borosilicate glass to a controlled heat treatment to induce phase separation, and then optionally leaching out one of the phases with an acid leach. The optical scattering element can be, for example, attached to an end of an optical fiber or bundle of optical fibers. The invention also relates to a method of dispersing or scattering light by transmitting the light through the optical scattering element.

Abstract: This disclosure provides an optical assembly, comprising a base body and a wave filtering apparatus. A first slot is disposed on an upper surface of the base body. A total internal reflection surface and a connecting part are formed in the first slot. The total internal reflection surface reflects collimated light formed by a first lens from a light emitting apparatus. The wave filtering apparatus comprises a first part removably connected to the connecting portion, and a second portion forming a beam splitting surface. The wave filtering apparatus has a light-pervious optical coating at least on the beam splitting surface of the apparatus, and is configured to split the collimated light reflected from the total internal reflection surface into a first beam and a second beam. The first beam travels towards the side where the third lens is located, and the second beam travels towards a photoelectric detection apparatus.

Abstract: The apparatus includes a case having a base member, two partial side members, and a lid member to provide a spatial volume with an opening at a back end of the base member. Additionally, the apparatus includes a PCB installed inside the spatial volume over the base member with a pluggable connector at the back end. The apparatus includes one or more optical transmitting devices in transmit-optical-sub-assembly package, each being mounted upside-down on the PCB and including a built-in TEC module in contact with the lid member and a laser output port aiming toward the back end. Furthermore, the apparatus includes a silicon photonics chip including a fiber-to-silicon attachment module, mounted on the PCB and coupled to a modulation driver module and a trans-impedance-amplifier module. Moreover, the apparatus includes an optical input port and output port being back connected to the fiber-to-silicon attachment module.

Abstract: An ophthalmic endo-illumination system includes a light source that produces a light beam, a fiber port that receives an optical fiber, a condenser that couples at least a portion of the light beam into the optical fiber received at the fiber port, and a beam splitter disposed between the fiber port and the condenser. The beam splitter is configured to receive the light beam from the condenser and split the light beam into a first beam which is coupled to the optical fiber and a second beam which is coupled to a monitoring fiber. An optical sensor is provided to detect an amount of the second beam output from the monitoring fiber. The coupling efficiency of the first beam coupled into the optical fiber may be determined based on the amount of the second beam output from the monitoring fiber.

Abstract: A fiber optic fan-out/break-out kit Closure/Housing for protecting fiber optic strands associated with the fiber optic cable. The fiber optic fan-out/break-out Closure/Housing comprises of a female shell, a male shell, an insert piece and an insert tool. The insert tool is temporarily attached to the insert piece thereby screwing the insert piece into the male shell.

Abstract: Techniques, methods, structures and apparatus that provide the efficient coupling of light to/from one or more optical fibers to/from planar grating waveguide couplers positioned on photonic integrated circuits.

Abstract: The present invention is generally directed to a method of making a hollow-core photonic band gap preform from a specialty glass by pressing a specialty glass through a die to form a tube wherein the outer transverse shape of the tube is a hexagon, triangle, quadrilateral, or other polygon; stretching the tube to form a micro-tube with approximately the same outer transverse shape as the tube; stacking a plurality of micro-tubes into a bundle minimizing voids between adjacent micro-tubes and forming a central longitudinal void wherein the plurality of micro-tubes within the bundle comprise an inner structured region of the preform and the central void of the bundle comprises a hollow core in the preform; and inserting the bundle into a jacket tube. Also disclosed are the hollow-core photonic band gap preform and fiber formed by this method.

Abstract: According to the present invention, as a result of using a depressed or trench-assisted light-receiving waveguide in which the core is surrounded by a layer having a refractive index lower than that of a cladding as light-receiving means for receiving light outputted from a multi-core optical fiber, the layer of a low refractive index can inhibit the propagation of noise, etc. from the cladding to the core. Consequently, even in cases where the inter-core crosstalk is small, it is possible to accurately measure the inter-core crosstalk since components different from crosstalk-derived components in optical power are reduced.

Abstract: A side lighting optical fiber 1 having a core 2 containing a first light scattering agent 4, and a clad disposed generally concentric to the core and containing a second light scattering agent 5, such that light transmittance of the clad 3 at wavelength of 550 nm is in the range of 70-90%.

Abstract: An infrared cut filter may be used with an image sensor to remove infrared light components from image light received from a first side of the infrared cut filter prior to the image light reaching the image sensor to be disposed on a second side of the infrared cut filter. The infrared cut filter includes at least one red absorbing layer and an infrared reflector. The at least one red absorbing layer partially absorbs red light components within the image light. The infrared reflector reflects the infrared light components. The infrared reflector is disposed between the red absorbing layer and the first side of the infrared cut filter while the at least one red absorbing layer is disposed between the infrared reflector and the second side of the infrared cut filter.

Abstract: High power fiber lasers include large or very large mode area active fibers. Mode preserving pump combiners are situated to counter-pump the active fiber using one or more pump sources. The mode preserving pump combiners preserve single mode propagation in a signal fiber, and such combiners can be identified based on optical spectra, beam quality, or temporal response. Active fibers can also be included in a pump combiner so that the active fiber is splice free from an input end that receives a seed pulse to an output end. Peak powers of over 100 kW can be obtained.

Abstract: An optical receptacle has a first optical surface which receives incidence of light from a light emitting element, a reflecting surface which reflects the light along a substrate, a light separating section which separates light reflected at the reflecting surface into monitor light and signal light, a second optical surface which emits the monitor light toward a light receiving element, and a third optical surface which emits the signal light toward an optical fiber. The light separating section has a plurality of splitting transmissive surfaces which are vertical surfaces with respect to the optical axis of the light reflected at the reflecting surface and a plurality of splitting reflecting surfaces which are inclining surfaces with respect to the optical axis of the light reflected at the reflecting surface. The splitting transmissive surfaces and the splitting reflecting surfaces are alternately disposed in a first direction and in a second direction.

Abstract: A system is provided for combining laser light sources. The system includes: a stack of laser diode bar arrays, comprising two or more laser diode bar arrays, each laser diode bar array having multiple laser diodes; a multimode optical fiber; and a plurality of optical elements disposed between the stack of laser diode bar arrays and the multimode optical fiber, configured to direct light from the stack of laser diode bar arrays to the multimode optical fibers, the plurality of optical elements further including: a plurality of fast-axis collimating (FAC) lenses, wherein at least one FAC lens of the plurality of FAC lenses corresponds to each laser diode bar array. At least one FAC lens of the plurality of FAC lenses is misaligned with respect to the corresponding laser diode bar array.

Abstract: A head-wearable display includes a collimated light source, a beam steering mechanism, and a synchronization controller. The collimated light source selectively emits collimated light. The beam steering mechanism is optically coupled to receive the collimated light and angularly scans the collimated light between beam steering states that each redirect the collimate light to a different angular direction along at least one angular dimension. The beam steering mechanism is coupled to scan the collimated light across an eyebox. The synchronization controller is coupled to the collimated light source and the beam steering mechanism to synchronize selective emission of the collimated light from the collimated light source with the beam steering states of the beam steering mechanism to repetitiously draw an image in the eyebox.

Abstract: A luminous flux control member (200) of the present invention has: a light input surface (210); total reflection surfaces (220), which are formed at positions facing a light emitting element with the light input surface (210) therebetween; two light guide sections (230), which are formed such that respective cross-sectional areas thereof are reduced in the direction to be away from the light input surface (210) and the total reflection surface (220), said light guide sections being formed at facing positions with the light input surface (210) and the total reflection surface (220) therebetween; and two light output surfaces (240), which are formed on the outer surfaces of the two light guide sections (230), respectively.

Abstract: A vehicular display apparatus includes a light source and a light guide member. The light guide member includes (i) an interior portion that receives light from the light source and (ii) outer faces that reflect the light repeatedly to permit the light to propagate in the interior portion. The light guide member further includes a viewable portion and a light absorption member serving as a light attenuation portion. The viewable portion reflects a part of the light propagating in the interior portion towards a viewer side so as to appear to be luminous. The light absorption member absorbs a part of light reflected by the outer face.

Abstract: A plasmonic detector and method for manufacturing a plasmonic detector. The plasmonic detector comprises two nanoscale metallic rods coupled to a bias voltage; a nanoscale cavity formed between adjacent ends of the two nanoscale metallic rods; and an absorption material disposed in the nanoscale cavity for converting an electromagnetic field to an electric current for outputting via the nanoscale metallic rods.

Abstract: As kilowatt class fiber laser and amplifier systems become more in demand, there are ongoing efforts to improve optical fiber laser and amplifier designs to maximize efficiency and further increase the capacity of these high-energy optical fiber lasers and amplifiers. The present disclosure provides a fiber laser or amplifier system configured to efficiently and conveniently generate and couple high numerical aperture and high-energy pump light into a fiber laser or amplifier system.

Abstract: A photoelectric conversion device includes a circuit board, light emitting modules, light receiving modules, and an optical coupling lens. The light emitting modules and the light receiving modules are mounted on the circuit board. The optical coupling lens is mounted on the circuit board and includes a first mounting surface. The first mounting surface defines a first recess at a central portion thereof and four receiving grooves at four peripheral edges thereof apart from the first recess. The receiving grooves are exposed to the peripheral edges of the first mounting surface.

Abstract: A method for converting an optical signal, propagating in an optical fiber, into an electrical output signal, including the following steps: providing an optical interface having opposing flat surfaces and being formed of a material having a refractive index that is substantially higher than the refractive index of the optical fiber; disposing a first of the opposing flat surfaces of the interface adjacent an output end of the optical fiber, and disposing a photodetector adjacent a second of the opposing flat surfaces of the interface; whereby the optical signal is coupled into the photodetector and converted by the photodetector into an electrical output signal.

Abstract: An optical engine assembly includes a bench, an optoelectronic device, a fixed member and a plurality of fibers. The bench has a bearing surface and an extended sidewall with a predetermined height from the bearing surface. The sidewall has an upper surface parallel to the bearing surface. The optoelectronic device is disposed on the center of the upper surface and includes a plurality of active areas. The fixed member is disposed on the bearing surface and has a plurality of through holes and two pin holes. The fibers respectively pass through the through holes and a 45-degree beveled surface is formed at the front end of each fiber. The 45-degree beveled surfaces are aligned with the active areas, respectively.

Abstract: A tunable resonant system is provided and includes a microsphere that receives an incident portion of a light beam generated via a light source, the light beam having a fundamental mode, a waveguide medium that transmits the light beam from the light source to the microsphere, and a polarizer disposed in a path of the waveguide between the light source and the microsphere. The incident portion of the light beam creates a fundamental resonance inside the microsphere. A change in a normalized frequency of the wavelength creates a secondary mode in the waveguide and the secondary mode creates a secondary resonance inside the microsphere.

Abstract: Methods and article for optically trapping nano-sized objects by illuminating a coaxial plasmonic aperture are disclosed.

Abstract: Provided is a Schottky emitter having the conical end with a radius of curvature of 2.0 ?m on the emission side of an electron beam. Since a radius of curvature is 1 ?m or more, a focal length of an electron gun can be longer than in a conventional practice wherein a radius of curvature is in the range of from 0.5 ?m to not more than 0.6 ?m. The focal length was found to be roughly proportional to the radius of the curvature. Since the angular current intensity (the beam current per unit solid angle) is proportional to square of the electron gun focal length, the former can be improved by an order of magnitude within a practicable increase in the emitter radius. A higher angular current intensity means a larger beam current available from the electron gun and the invention enables the Schottky emitters to be used in applications which require relatively high beam current of microampere regime such as microfocus X-ray tube, electron probe micro-analyzer, and electron beam lithography system.

Abstract: An optical communication device includes a light emitting element including a light emitting surface, a processor, a first controller electrically connected to the light emitting element and electrically connected to the processor, a light receiving element including a light receiving surface, a storing element, a second controller electrically connected to the light receiving element and electrically connected to the storing element, a first coating element coating the light emitting element, the first controller, the processor, the light receiving element, the second controller, and the storing element, a planar optical waveguide, and two reflecting elements. The first coating element includes a supporting surface. The supporting surface defines two light guiding holes. The planar optical waveguide is positioned on the supporting surface, and defines two through holes. Each through hole spatially corresponds to and communicates with a light guiding hole.

Abstract: The present invention relates to a multi-core optical fiber applicable to an optical transmission line of bi-directional optical communication and a bi-directional optical communication method. The multi-core optical fiber has plural cores in a common cladding. Signal light is transmitted in a first direction through an arbitrary core among the cores, whereas the signal light is transmitted in a second direction opposite to a first direction, through all the nearest-neighbor cores to the arbitrary core.

Abstract: An obstacle sensor includes a line light irradiating unit including a light-emitting unit, a light-emitting driving unit to drive the light-emitting unit, and a first conical mirror, an apex of which is disposed towards the light-emitting unit in a light irradiation direction of the light-emitting unit and which converts light emitted from the light-emitting unit into line light irradiated in all directions, and a reflected light receiving unit including a second conical mirror to condense light, that is irradiated from the first conical mirror and is then reflected from an obstacle, a lens, that is spaced from the apex of the second conical mirror by a predetermined distance and transmits the reflected light, an imaging unit to image the reflected light that passes through the lens, an image processing unit, and an obstacle sensing control unit.