Abstract: The present invention aims to provide a low-wavelength-dependent optical coupler capable of concurrently achieving high process stability and low polarization dependence. An optical coupler 100 according to an embodiment includes a cladding layer 105 being formed on a substrate 104 and having two waveguides 101a, 101b inside. Three directional couplers 102a, 102b, 102c are each formed by bringing portions of the two waveguides close to each other in parallel, and the two delay paths 103a, 103b are each formed to give an optical path difference between the two waveguides. The delay path 103a is provided between the directional couplers 102a and 102b, and the delay path 103b is provided between the directional couplers 102b and 102c. The three directional couplers have the same coupling characteristic, and the two delay paths have different optical path differences from each other.

Abstract: An optical waveguide directional coupler includes a base having a planar member and a ridge member and an optical waveguide in the base. The ridge member extends from the planar member and has an upper surface where the optical waveguide exposed. The optical waveguide includes a first flat side surface, a second flat side surface parallel to the first flat side surface, a third flat side surface, a fourth flat side surface parallel to the third flat side surface, and a first flat connection side surface. An included angle ?1 between the first and third flat side surfaces is an obtuse angle, an included acute angle ?1 is formed between the first flat connection side surface and the second flat side surface, and ?1 and ?1 satisfy ?1<(180°??1).

Abstract: An optical waveguide directional coupler includes a base and two optical waveguides formed in the base. The base has a ridge portion, and a planar portion adjacent to the ridge portion. Each of the optical waveguides includes a first straight section located in the ridge portion, a second straight section, and a curved section interconnected between the first and second straight sections. The curved sections and the second straight sections are located in the planar portion. The first straight sections are parallel with each other and define a light coupling region therebetween. The second straight sections are parallel with each other, and a distance between the second straight sections being greater than a distance between the first straight sections.

Abstract: An optical waveguide directional coupler includes a base and a Y-shaped optical waveguide formed in the base. The base includes a planar member and a ridge member extending from a side of the planar member. The planar member includes a top surface. The ridge member includes a recessed planar portion and a raised portion raised relative to the recessed planar portion and perpendicularly extending from the planar member. The raised portion has an upper surface coplanar with the top surface. The Y-shaped optical waveguide is exposed to the upper surface and the top surface. One end of the Y-shaped optical waveguide is exposed to an end of the ridge member, and the other two ends are exposed to an end of the planar member.

Abstract: Provided is a bidirectional optical module having an improved structure capable of bidirectionally transmitting an optical signal.

Abstract: The inventive concept provides optic couplers, optical fiber laser devices, and active optical modules using the same. The optic coupler may include a first optical fiber having a first core and a first cladding surrounding the first core, a second optical fiber having a second core transmitting a signal light to the first optical fiber and a third cladding surrounding the second core, third optical fibers transmitting pump-light to the first optical fiber in a direction parallel to the second optical fiber; and a connector connected between the first optical fiber and the second optical fiber, the connector extending the third optical fibers disposed around the second optical fiber toward the first optical fiber, the connector comprising a third core connected between the first core and the second core and a fifth cladding surrounding the third core.

Abstract: A reflective structure includes an input/output port and an optical splitter coupled to the input/output port. The optical splitter has a first branch and a second branch. The reflective structure also includes a first resonant cavity optically coupled to the first branch of the optical splitter. The first resonant cavity comprises a first set of reflectors and a first waveguide region disposed between the first set of reflectors. The reflective structures further includes a second resonant cavity optically coupled to the second branch of the optical splitter. The second resonant cavity comprises a second set of reflectors and a second waveguide region disposed between the second set of reflectors.

Abstract: An optical transmitter includes three or more emission optical fibers that are three-dimensionally arranged, a single reception optical fiber, and an optical path converting component to optically couple the emission optical fibers to the reception optical fiber. The optical path converting component includes optical transmission portions that are optically coupled to the three or more emission optical fibers one to one, respectively, and optically coupled commonly to the single reception optical fiber. Entry ends of the optical transmission portions are aligned with exit ends of the three or more emission optical fibers, respectively. Exit ends of the optical transmission portions are aligned, as a whole, with an entry end of the single reception optical fiber. The exit ends of the optical transmission portions are arranged substantially parallel to one another and in closer proximity to one another than the entry ends of the optical transmission portions.

Abstract: An optical fiber coupler is formed of a section of optical fiber that is positioned between a conventional input fiber (for example, a single mode fiber) or waveguide and a coiled optical fiber device. The adiabatic coupler is coiled (or, at least, curved) to assist in transforming a conventional fundamental mode optical signal propagating along the longitudinal axis of the input fiber to an optical signal that is shifted into a peripheral region of the coiled optical fiber. Moreover, the pitch of an inventive coiled optical fiber coupler can be controlled to assist in the adiabatic transformation process.

Abstract: We present optical systems suitable for focusing two substantially collimated beams or sheets of light propagating in different directions onto a common focal point. In some embodiments the optical systems comprise separate focusing elements for each beam or sheet of light, while in other embodiments the optical systems comprise a focusing element and a redirection element. The optical systems have particular application in the receive optics of infrared touch screens, where they enable the detection of additional light paths that assist in the determination of two or more simultaneous touch events.

Abstract: Apparatus and methods that compensate for the thermally-induced drift of the resonance frequency of a closed-loop resonator include, in an exemplary embodiment, a waveguide-based Mach-Zehnder interferometer (MZI) and an overcoupled, waveguide-based microring resonator. The temperature-induced red-shifting ring resonance can be balanced by a spectral blueshift with temperature of the MZI. To stabilize the resonance of the ring at a given wavelength, the change in optical path lengths with temperature of the ring and the MZI should be equal and opposite. The interplay of nonlinear change in phase of ring resonator with temperature and linear change in phase of MZI with temperature, along with matching the period of this phase change, gives rise to perfect oscillation in the combined system resonance with temperature.

Abstract: An optical waveguide device includes an optical branch device for branching a first input light and outputting the branched first input light to a first and a second optical waveguides, another optical branch device, arranged between the first and the second optical waveguides, for branching a second input light and outputting the branched second input light to a third and a fourth optical waveguides, an optical coupler which couples the lights traveling along the first and the third optical waveguides, then branches the coupled lights, and outputs them; and another optical coupler which couples the lights traveling along the second and the fourth optical waveguides, then branches the coupled lights, and outputs them, wherein optical path lengths of either a pair of the first and the second optical waveguides or a pair of the third and the fourth optical waveguides are set to be equal.

Abstract: A method and system for coupling optical signals into silicon optoelectronic chips are disclosed and may include coupling one or more optical signals into a back surface of one or more of a plurality of CMOS photonic chips comprising photonic, electronic, and optoelectronic devices. The devices may be integrated in a front surface of the chips and optical couplers may receive the optical signals in the front surface of the chips. The optical signals may be coupled into the back surface of the chips via optical fibers and/or optical source assemblies. The optical signals may be coupled to the optical couplers via a light path etched in the chips, which may be refilled with silicon dioxide. The chips may be flip-chip bonded to a packaging substrate. Optical signals may be reflected back to the optical couplers via metal reflectors, which may be integrated in dielectric layers on the chips.

Abstract: The present invention provides a 90-degree hybrid capable of miniaturization and also capable of a stable operation in a wide band. According to an embodiment of the present invention, a PLC-type 90-degree hybrid comprises: a PLC chip having a planar lightwave circuit formed therein; and a 90-degree hybrid circuit formed in the planar lightwave circuit, mixing a modulated signal light and an LO light to separate the signal light into quadrature components I and Q, and outputting the same. The 90-degree hybrid circuit includes: two Y-branch couplers each branching the signal light and the LO light; and two wavelength-independent directional couplers which cause LO lights passing through two paths and signal lights passing through two paths to interfere with each other, respectively. The above-described paths include waveguides having mutually inverted shapes and waveguides having an identical shape, and have a shape substantially symmetrical with respect to the signal light.

Abstract: Various embodiments of patch panel devices are enclosed. In some embodiments, signals received are in an electrical or optical form and converted to the other form. The converted signal is provided as an output signal. A version of the original input may also be provided as an input. A signal injector can inject a optical or electrical signal that is selectively injected into the output signals. Various embodiments also include sensor to detecting the connecting of an electrical or optical line.

Abstract: Methods and systems for generating a supercontinuum light source, including generating electromagnetic radiation from a seed laser; coupling the seed laser electromagnetic radiation to a fiber amplifier comprising: a pump laser, a fiber coupler comprising an input and an output, and a nonlinear gain fiber comprising an input and an output, wherein the nonlinear gain fiber is configured to amplify and broaden the electromagnetic radiation from the seed laser; generating electromagnetic radiation from the pump laser; coupling the pump laser electromagnetic radiation and the seed laser electromagnetic radiation into the input of the fiber coupler; coupling the output of the fiber coupler into the input of the nonlinear gain fiber; and coupling out the amplified and broadened electromagnetic radiation from the nonlinear gain fiber. Other embodiments are described and claimed.

Abstract: A waveguide-type optical circuit comprises an optical coupler being an optical branch coupler constructed from waveguide cores which are closely arranged to each other, and dummy patterns that lay along sides of the waveguide cores in the optical coupler for preventing optical major axes of the waveguide cores from inclining.

Abstract: An optical wavelength multiplexing/de-multiplexing circuit having a low loss and a flat transmission spectrum is provided. The optical wavelength multiplexing/de-multiplexing circuit compensates a temperature dependence of a center transmission wavelength which remains in an athermal AWG, and has an excellent accuracy of the center transmission wavelength in a whole operating temperature range or has a comparatively wide operable temperature range. The temperature dependence of the transmission wavelength in the athermal MZI is modulated and set so as to cancel the temperature dependence of the center wavelength which remains in the athermal AWG. The present invention focuses particularly on an optical coupler in the MZI and modulates the temperature dependence of the transmission wavelength in the MZI by providing the optical coupler itself with a mechanism which changes a phase difference between two outputs by temperature.

Abstract: An optical semiconductor device, including a first optical waveguide with a first width, a second optical waveguide with a second width narrower than the first width with a bending region, and a third optical waveguide with a third width wider than the second width and coupled to the second optical waveguide.

Abstract: An optical bus. Optical sub-assemblies are used to connect lengths of optical fiber to form a single optical fiber that is a bus. A master transceiver may be connected to one end of the fiber and nodes can be connected to the optical sub-assemblies. Each optical sub-assembly includes a center fiber with a mirror that enables each connector to reflect optical signals out of the fiber and that enables a node to launch optical signals on the optical bus. The optical bus can also be connected with a second transceiver that may be used to deliver optical power to the attached nodes. Some nodes include two optical subassemblies to enable bidirectional communication on the optical bus.

Abstract: A multi-chip module (MCM) includes a stack of chips that are coupled using optical interconnects. On a first surface of a middle chip in the stack, there are: a first optical coupler, an optical waveguide, which is coupled to the first optical coupler, and a second optical coupler, which is coupled to the optical waveguide. The first optical coupler redirects an optical signal from the optical waveguide to a first direction (which is not in the plane of the first surface), or from the first direction to the optical waveguide. The second optical coupler redirects the optical signal from the optical waveguide to a second direction (which is not in the plane of the first surface), or from the second direction to the optical waveguide. An optical path associated with the second direction passes through an opening in a substrate in the middle chip.

Abstract: This document discusses, among other things, a connector for an optical imaging probe that includes one or more optical fibers communicating light along the catheter. The device may use multiple sections for simpler manufacturing and ease of assembly during a medical procedure. Light energy to and from a distal minimally-invasive portion of the probe is coupled by the connector to external diagnostic or analytical instrumentation through an external instrumentation lead. Certain examples provide a self-aligning two-section optical catheter with beveled ends, which is formed by separating an optical cable assembly. Techniques for improving light coupling include using a lens between instrumentation lead and probe portions. Techniques for improving the mechanical alignment of a multi-optical fiber catheter include using a stop or a guide.

Abstract: An optical hybrid circuit includes a multimode interference coupler; a first 2:2 optical coupler; a second 2:2 optical coupler; a third 2:2 optical coupler; and a phase controlling region. The first 2:2 optical coupler, the second 2:2 optical coupler, and the third 2:2 optical coupler are coupled to one of the pair of first output channels, the pair of second output channels, the pair of third output channels, and the pair of fourth output channels of the multimode interference coupler. The phase controlling region is provided in one or both of each pair of at least two pairs of output channels from among three pairs of output channels to which the first 2:2 optical coupler, the second 2:2 optical coupler, and the third 2:2 optical coupler are coupled, respectively.

Abstract: Nanoribbons and nanowires having diameters less than the wavelength of light are used in the formation and operation of optical circuits and devices. Such nanostructures function as subwavelength optical waveguides which form a fundamental building block for optical integration. The extraordinary length, flexibility and strength of these structures enable their manipulation on surfaces, including the precise positioning and optical linking of nanoribbon/wire waveguides and other nanoribbon/wire elements to form optical networks and devices. In addition, such structures provide for waveguiding in liquids, enabling them to further be used in other applications such as optical probes and sensors.

Abstract: A method and system for coupling optical signals into silicon optoelectronic chips are disclosed and may include coupling one or more optical signals into a back surface of a CMOS photonic chip comprising photonic, electronic, and optoelectronic devices. The devices may be integrated in a front surface of the chip and one or more grating couplers may receive the optical signals in the front surface of the chip. The optical signals may be coupled into the back surface of the chip via one or more optical fibers and/or optical source assemblies. The optical signals may be coupled to the grating couplers via a light path etched in the chip, which may be refilled with silicon dioxide. The chip may be flip-chip bonded to a packaging substrate. Optical signals may be reflected back to the grating couplers via metal reflectors, which may be integrated in dielectric layers on the chip.

Abstract: An optical fiber coupler is formed of a section of optical fiber that is positioned between a conventional input fiber (for example, a single mode fiber) or waveguide and a coiled optical fiber device. The adiabatic coupler is coiled (or, at least, curved) to assist in transforming a conventional fundamental mode optical signal propagating along the longitudinal axis of the input fiber to an optical signal that is shifted into a peripheral region of the coiled optical fiber. Moreover, the pitch of an inventive coiled optical fiber coupler can be controlled to assist in the adiabatic transformation process.

Abstract: The invention relates to devices having periodic refractive index modulation structures and fabrication methods for the devices using a laser means. By focusing a pulsed laser beam into a transparent material substrate, a path of laser modified volumes can be formed with modified refractive index compared with the unprocessed material. By selecting appropriate laser parameters and relative scan speed, the laser modified path defines an optical waveguide. Separation distance of the individual modified volumes define a periodic modification pattern along the waveguide path, so that the waveguide structures also exhibit grating responses, for example, as spectral filters, Bragg reflectors, grating couplers, grating sensors, or other devices.

Abstract: In some variations, the present invention provides a method for forming a chip-scale photonic frequency channelizer or spectrum analyzer. A low-loss waveguide forms a long delay-line in a first level, from which a large number of filter-taps form narrow channel passbands. Multi-dimensional laser-written waveguides feed a slab waveguide coupler located at a stacked, second level. A chip-scale RF-photonic spectrum analyzer provided by this invention has extremely high resolution, such as a passband width of about 30 MHz over a free spectral range of 12 GHz, while occupying a device footprint of only about 10 cm2 area.

Abstract: A radiation waveguide member comprises a closed chamber provided with multilayer asymmetrical graded-index medium. The radiant heat exchange is unbalanced between the open surface of the closed chamber and a single heat source, and the positive and negative values of the net radiant heat flux is generated. An automatic directional waveguide of the radiation of the single source is formed from the negative-value open surface to the positive-value open surface. The radiation waveguide member enables aggregating a low-density energy flow into a high-density energy flow.

Abstract: The present invention provides a 90-degree hybrid capable of miniaturization and also capable of a stable operation in a wide band. According to an embodiment of the present invention, a PLC-type 90-degree hybrid comprises: a PLC chip having a planar lightwave circuit formed therein; and a 90-degree hybrid circuit formed in the planar lightwave circuit, mixing a modulated signal light and an LO light to separate the signal light into quadrature components I and Q, and outputting the same. The 90-degree hybrid circuit includes: two Y-branch couplers each branching the signal light and the LO light; and two wavelength-independent directional couplers which cause LO lights passing through two paths and signal lights passing through two paths to interfere with each other, respectively. The above-described paths include waveguides having mutually inverted shapes and waveguides having an identical shape, and have a shape substantially symmetrical with respect to the signal light.

Abstract: The variable wavelength light source includes a multiple ring resonator including a plurality of resonators, photodetectors which detect light powers outputted from at least two out of the plurality of resonators via throughports, a plurality of variable light units for changing the transmittance of the multiple ring resonator by individually working on at least two out of the plurality of resonators, a light input/output unit which supplies the light to the multiple resonator and emits the light returned from the multiple resonator towards the outside, and a control unit which controls the plurality of variable light units in accordance with the light power detected by the photodetectors, wherein light attenuators are arranged between the throughports and the photodetectors for attenuating the light emitted from the throughports before making incident on the photodetectors.

Abstract: A fiber-optic coupler packaging including an internal encapsulation for encapsulating a fiber-optic coupler, the refraction index of the internal encapsulation is smaller than the refraction index of the fiber-optic coupler, and an external encapsulation, for encapsulating the internal encapsulation, the refraction index of the external encapsulation is greater than the refraction index of the internal encapsulation, the internal encapsulation and the external encapsulation are substantially transparent to the range of wavelengths of the light traveling inside the fiber-optic coupler.

Abstract: An optical device has two optical waveguides embedded in a clad. The optical waveguides are mutually parallel and are separated by a distance that allows optical coupling between them. The optical waveguides have identical square cross sectional shapes in a plane orthogonal to the direction of light propagation, so that light propagates through each optical waveguide without polarization dependence. The length of each side of the square cross section of the optical waveguides is determined from the refractive index of the clad and the distance between the longitudinal axes of the optical waveguides so that coupling between the two optical waveguides is also polarization independent for light with a wavelength of 1.49 micrometers, which is the longer of the two wavelengths used in optical subscriber networks.

Abstract: A system and method for a structure monitoring and locating a disturbance event is disclosed. The system includes a compact transceiver chip sending optical signals in three optical fibers that encompass the monitored structure appropriately. The system contains a sequence of loops, wherein the first and the second fiber forming the loop clockwise, while the third fiber is winded along the same loop counterclockwise. A set of two detectors registers the returning signals, and a time delay between those signals is calculated, which is indicative of the disturbance event location. The event location is determined with different sensitivity in different parts of the monitored structure depending on the density of fibers in these parts.

Abstract: In an optical interferometer, polarization dependence attributable to the optical path difference has conventionally been eliminated by inserting a half-wave plate at the center of the interferometer. However, light induced by polarization coupling produced in directional couplers used in the optical interferometer causes interference having different interference conditions from those of the normal light. Polarization rotators that effect any one of 90° rotation and ?90° rotation of all states of polarization of incoming light are inserted in the optical interferometer, and thereby the interference conditions of light induced by polarization coupling are made the same as those of the normal light. Each of the polarization rotators is implemented by using two half-wave plates and by varying an angle of combination of these half-wave plates. Alternatively, each of the polarization rotators is implemented through a combination of one half-wave plate and a waveguide having birefringence properties.

Abstract: An architecture for the handling and transport of nanoscopic matter in lab on a chip devices using optical forces. A slot waveguide is used to focus and harness optical energy to trap and transport nanoscale objects. The slot waveguide is a unique structure that has several advantageous features, such as high optical confinement, and enables nanoparticles to interact fully with a propagating optical mode.

Abstract: A waveguide and resonator are formed on a lower cladding of a thermo optic device, each having a formation height that is substantially equal. Thereafter, the formation height of the waveguide is attenuated. In this manner, the aspect ratio as between the waveguide and resonator in an area where the waveguide and resonator front or face one another decreases (in comparison to the prior art) thereby restoring the synchronicity between the waveguide and the grating and allowing higher bandwidth configurations to be used. The waveguide attenuation is achieved by photomasking and etching the waveguide after the resonator and waveguide are formed. In one embodiment the photomasking and etching is performed after deposition of the upper cladding. In another, it is performed before the deposition. Thermo optic devices, thermo optic packages and fiber optic systems having these waveguides are also taught.

Abstract: A novel electroabsorption modulator based on tuning the Fermi level relative to mid-gap states in a semiconductor. The modulator includes a semiconductor waveguide that has an input port and an output port. Between the input port and the output port is a section of the waveguide that functions as an electroabsorptive region. Adjacent to the electroabsorptive region are electrical contacts. In operation by adjusting voltages on the electrical contacts, the quasi-Fermi level in the electroabsorptive region of the semiconductor waveguide is brought above or below mid band-gap electronic states. As these states transition between occupancy and vacancy, the absorption coefficient for optical radiation in the electroabsorptive region of the semiconductor changes.

Abstract: A double clad fiber includes a core, a first cladding provided so as to cover the core, and a second cladding provided so as to cover the first cladding. The second cladding has a plurality of pores extending in a length direction and arranged so as to surround the first cladding. In at least one fiber end, the second cladding has been removed by mechanical processing so that the at least one fiber end is formed by the core and the first cladding.

Abstract: Various embodiments of patch panel devices are enclosed. In some embodiments, signals received are in an electrical or optical form and converted to the other form. The converted signal is provided as an output signal. A version of the original input may also be provided as an input. A signal injector can inject a optical or electrical signal that is selectively injected into the output signals. Various embodiments also include sensor to detecting the connecting of an electrical or optical line.

Abstract: A method to maximize the coupling efficiency between a collimated, free-space optical signal and a fiber optic waveguide using an active optical element to steer and focus the collimated beam driven by an adaptive controller that periodically auto-calibrates the active optical element's parameters to maximize the measured power received by the waveguide using a gradient ascent optimization algorithm.

Abstract: It is provided a polarization-independent optical isolator without depending on the polarized wave of the light being input to the waveguide-type optical isolator, in particular, it is able to completely isolate the propagating light of the backward direction.

Abstract: An optical apparatus comprises: a waveguide substrate; three planar optical waveguides formed on the substrate, each comprising a transmission core and cladding; a laser positioned to launch its optical output to propagate along the first waveguide; a photodetector positioned to receive an optical signal propagating along the second waveguide; and a lateral splitter core formed on the substrate for (i) transferring a first fraction of laser optical output propagating along the first waveguide to the second waveguide, and (ii) transferring a second fraction of the laser optical output propagating along the first waveguide to the third waveguide.

Abstract: A waveguide and resonator are formed on a lower cladding of a thermo optic device, each having a formation height that is substantially equal. Thereafter, the formation height of the waveguide is attenuated. In this manner, the aspect ratio as between the waveguide and resonator in an area where the waveguide and resonator front or face one another decreases (in comparison to the prior art) thereby restoring the synchronicity between the waveguide and the grating and allowing higher bandwidth configurations to be used. The waveguide attenuation is achieved by photomasking and etching the waveguide after the resonator and waveguide are formed. In one embodiment the photomasking and etching is performed after deposition of the upper cladding. In another, it is performed before the deposition. Thermo optic devices, thermo optic packages and fiber optic systems having these waveguides are also taught.

Abstract: A method of making a planar lightwave circuit (PLC) waveguide capable of being integrated with a surface-mounted component is presented. The method entails etching a silicon substrate to form a slanted wall, forming a nonreflective waveguide portion on the silicon substrate, and depositing a reflective layer on the slanted wall. Light travels through the nonreflective waveguide portion in substantially a first direction, and the light from the nonreflective waveguide portion strikes the reflective layer to be redirected in a second direction. The second direction may be the direction toward the surface-mounted component. A PLC waveguide device made with the above method is also presented.

Abstract: A multi-chip module (MCM), which includes a three-dimensional (3D) stack of chips that are coupled using optical interconnects, is described. In this MCM, disposed on a first surface of a middle chip in the 3D stack, there are: a first optical coupler, an optical waveguide, which is coupled to the first optical coupler, and a second optical coupler, which is coupled to the optical waveguide. The first optical coupler redirects an optical signal from the optical waveguide to a first direction (which is not in the plane of the first surface), or from the first direction to the optical waveguide. Moreover, the second optical coupler redirects the optical signal from the optical waveguide to a second direction (which is not in the plane of the first surface), or from the second direction to the optical waveguide. Note that an optical path associated with the second direction passes through an opening in a substrate in the middle chip.

Abstract: A self-written branched optical waveguide is formed. A laser beam 2 from a laser source (not shown) is focused with a lens 3 onto the face of incidence 10 of an optical fiber 1. The laser beam of an LP11 mode was emitted from the face of emergence 11, and “bimodal” light intensity peaks were arranged in the horizontal direction (1.A). A slide glass 4 coated with a photocurable resin gel 5 was placed horizontally (1.B). A single linear cured material 61 was formed as the LP11-mode laser beam was emitted from the face of emergence 11 of the optical fiber 1 (1.C). A branch portion 62 was then formed at a distance L from the face of emergence 11 of the optical fiber 1, which was followed by the growth of two cylindrical cured materials 63a and 63b. The two cylindrical cured materials 63a and 63b were linear branches, and formed an angle of about four degrees. An optical waveguide 60 thus formed was composed of cured materials 61, 62, 63a, and 63b (1.D).

Abstract: An optical apparatus including a 360-degree star coupler with derivative structure(s) and applications to optical imaging, optical communications and optical spectroscopy.

Abstract: A leaky plasmon mode directional coupler and a polarization detection module for a magneto-optical pickup head, which uses the leaky plasmon mode directional coupler, are provided. The leaky plasmon mode directional coupler is manufactured by integrating a planar waveguide and a leaky plasmon mode waveguide, which share a cladding layer with each other, into one body. The polarization detection module includes the leaky plasmon mode directional coupler, a first photo diode, which is formed on the leaky plasmon mode directional coupler, and a second photo diode, which is located at an output port of the planar waveguide.

Abstract: An optical device has two optical waveguides embedded in a clad. The optical waveguides are mutually parallel and are separated by a distance that allows optical coupling between them. The optical waveguides have identical square cross sectional shapes in a plane orthogonal to the direction of light propagation, so that light propagates through each optical waveguide without polarization dependence. The length of each side of the square cross section of the optical waveguides is determined from the refractive index of the clad and the distance between the longitudinal axes of the optical waveguides so that coupling between the two optical waveguides is also polarization independent for light with a wavelength of 1.49 micrometers, which is the longer of the two wavelengths used in optical subscriber networks.