Abstract: A novel germanium (Ge) photodetector is disclosed, containing a stripe layer including Ge, a substrate supporting the stripe layer, and P and N regions, which are located inside the substrate and near opposite sides of the stripe. The stripe layer containing Ge for light absorption is operated in a slow-light mode by adding combinations of a gradual taper indent structure and a periodic indent structure to reduce light scatterings and to control light group velocity inside the stripe. Due to the slower light traveling velocity inside the stripe, the absorption coefficient of the stripe containing Ge is upgraded to be 1 to 2 orders of magnitude larger than that of a traditional bulk Ge at L band, and so the absorption coefficient reaches more than 1 dB/?m at the wavelength of 1600 nm.

Abstract: Provided are a spot size converter and a method of manufacturing the spot size converter. The method includes stacking a lower clad layer, a core layer, and a first upper clad layer on a substrate, tapering the first upper clad layer and the core layer in a first direction on a side of the substrate, forming a waveguide layer on the first upper clad layer and the lower clad layer, and etching the waveguide layer, the first upper clad layer, the core layer, and the lower clad layer such that the waveguide layer is wider than a tapered portion of the core layer on the side of the substrate and has the same width as that of the core layer on another side of the substrate.

Abstract: Waveguide designs and fabrication methods provide adiabatic waveguide eigen mode conversion and can be applied to monolithic vertical integration of active and passive elements in PICs. An advantage of the designs and methods is a simple fabrication procedure with only a single etching step in combination with subsequent well-controllable selective oxidation. As a result, improved manufacturability and reliability can be achieved.

Abstract: To provide a tapered optical fiber having a good outer diameter accuracy and a high reproducibility, a manufacturing method of the tapered optical fiber, and a manufacturing system of the tapered optical fiber. The above-mentioned problem is solved by manufacturing system 1 of a tapered optical fiber comprising: shifter 11, 12 which reciprocates optical fiber 10 mounted at positions having a prescribed distance therebetween in the longer direction X of optical fiber 10 (the direction of the optical axis); and heating device 13 which heats the reciprocating optical fiber 10 at fixed position O, wherein shifter 13 includes a broadening unit which can increase the mounting distance (L1+L2) of the optical fiber while reciprocating the optical fiber. Shifter 11, 12 has at least two mounting unit which fix the optical fiber 10, and serves as a broadening unit controlling the two mounting unit independently or interlockingly.

Abstract: Provided are optical coupling devices and silicon photonics chips having the same. the optical coupling device may include a lower layer having a first region and a second region, a first core layer disposed on the lower layer, the first core layer including first and second waveguides disposed on the first and second regions, respectively, a clad layer covering the first waveguide, and a second core layer interposed between the clad layer and the lower layer to cover the second waveguide. The second waveguide has a width decreasing with increasing distance from the first region and a vertical thickness greater than that of the first waveguide.

Abstract: A spot size converter includes a first silicon waveguide core that includes a width-fixed region having a fixed width and a width-tapered region continuing to the width-fixed region and having a width reducing toward a terminal portion, and a second waveguide core continuing to the first silicon waveguide core and covering at least the width-tapered region. The first silicon waveguide core has a thickness-wise step in the width-fixed region.

Abstract: A method for forming a waveguide having a thin-core region, a thick-core region, and a transition region of tapered thickness between them is disclosed. The method comprises forming a lower core layer of a first material on a lower cladding, forming a thin central core layer of a second material on the first core layer, forming an upper core layer of the first material on the central core layer, and etching the upper core layer in an etchant such that it is removed from the thin-core region and its thickness monotonically changes from its as-deposited thickness to extinction across the transition region, where the central core layer protects the lower core layer from exposure to the etchant.

Abstract: In a waveguide device, unnecessary optical power is appropriately terminated. According to an embodiment of the present invention, the waveguide device has a termination structure filled with a light blocking material to terminate light from a waveguide end. In the termination structure, a cladding and a core are removed to form a groove on an optical waveguide. The groove is filled with a material (light blocking material) that attenuates the intensity of light. Thus, light input to the termination structure is attenuated by the light blocking material, suppressing crosstalk which possibly effects on other optical devices. Thus, such a termination structure can restrain crosstalk occurred in optical devices integrated in the same substrate and can also suppress crosstalk which possibly effects on any other optical device connected directly to the substrate.

Abstract: Provided is a connecting channel that has manufacturing tolerance, can suppress light loses, improves reliability of the connecting channel, and connects an optical device and an optical waveguide. The connecting channel includes first silicon layer (3) that has rib-shaped part (3?) extending in a longitudinal direction of the connecting channel, and second silicon layer (6) that is stacked on first silicon layer (3) to partially overlap rib-shaped part 3?, and extends in the longitudinal direction. Second silicon layer (6) has tapered part (W) tapered toward one end in the longitudinal direction, and is located away from an upper portion of rib-shaped part (3?) at an end surface of one end in the longitudinal direction.

Abstract: The present invention relates generally to optical waveguides for the transmission of electromagnetic energy. The present invention relates more particularly to optical couplers for coupling optical fibers, and methods for making them. One aspect of the present invention is an optical coupler for use with a polarization-maintaining input optical fiber and a polarization-maintaining output optical fiber.

Abstract: Embodiments of the present disclosure include devices that split a light beam into two separate paths, with reduced sensitivity to fabrication variation. The devices can operate as 3-dB splitters that divide the input optical energy equally between two output waveguides. Similarly, the devices can also function to combine two light beams into a single path (coupler). The designs make use of adiabatic modal evolution and do not require physical symmetry along the entire device length.

Abstract: A planar optical waveguide device, includes: two input portions that are waveguides that have the same width, are parallel to each other, and have rectangular cross-sections; a wide portion that is a linear waveguide and is connected after the two input portions; a tapered portion that is connected after the wide portion and that is a multi-mode waveguide which has a tapered shape having a width decreasing gradually and through which at least TE1 propagates; and an output portion that is connected after the tapered portion and that is a multi-mode waveguide which has a rectangular cross-section and through which at least TE1 propagates. The planar optical waveguide device forms a high-order mode conversion combining element that outputs the TE0, which is input to the two input portions, as the TE1 from the output portion.

Abstract: Alignment of a single-mode polymer waveguide (PWG) array fabricated on a polymer with a silicon waveguide (SiWG) array fabricated on a silicon (Si) chip and thereby realizing an adiabatic coupling. A stub and a groove are fabricated with high precision and made to function as the absolute positioning reference to provide a self-alignment according to the groove and the stub. In a PWG patterning by photolithography, plural masks are used, but the fabrication is made along the alignment base line for mask and thus a high precision is achieved with respect to error ?x. In a PWG patterning by nano imprint, a high precision in the fabrication is also achieved with respect to error ?x and ?y.

Abstract: An optical converter and a method of manufacturing the optical converter are provided. The optical converter may include a signal receiving portion configured to receive an optical signal from an optical fiber which can be coupled to the optical converter, a signal output portion configured to output the optical signal received by the signal receiving portion, and a signal coupling portion being disposed between the signal receiving portion and the signal output portion and being configured to couple the optical signal received by the signal receiving portion into the signal output portion. The signal output portion may include a waveguide element having at least one tapered end section, and being partially or wholly surrounded by the signal coupling portion. The at least one tapered end section may be configured to couple the optical signal from the signal coupling portion into the waveguide element and the waveguide element may be configured to output the optical signal.

Abstract: The device includes a main waveguide on a base. The main waveguide is configured to guide a light signal through a light-transmitting medium. The device also includes multiple transition waveguides on the base. Each of the transition waveguide intersects a terminal end of the main waveguide such that each transition waveguide receives a different portion of the light signal from the main waveguide. The device also includes one or more light sensors positioned on the base. Each transition waveguide guides the received light portions to the one or more light sensors such that each of the light signal portions is received at the one or more light sensors.

Abstract: A light collector includes a light guide having a refractive index larger than a refractive index of air and a reflecting surface configured to reflect light output from a conic surface of the light guide back to the light guide. The light guide is made of transparent material through which light passes. The light guide has an entering portion from which light enters and an exiting portion from which the light exits. The light guide has a circular cone shape and has a cross-sectional area that decreases in a direction from the entering portion to the exiting portion.

Abstract: Provided are an optical coupler and an arrayed-waveguide grating structure including the same. The coupler includes a lower clad layer, a core comprising a slab waveguide region disposed on one side of the lower clad layer and a ridge waveguide region disposed on the other side of the lower clad layer, and an upper clad disposed on the core, wherein the ridge waveguide region comprises a self-focusing region configured to focus an optical signal provided form the slab waveguide region and thus to prevent scattering of the optical signal.

Abstract: A side pump fiber and a method of making a side pump fiber are provided. A plurality of pump fibers can be joined to a side of a signal fiber, at different locations. The method includes creating a lengthwise, tapered, concave pocket cut in a pump (or side pump) fiber, inserting the signal fiber in the pocket cut, and then coupling the side pump fiber to the center fiber at the pocket cut. Optical amplifiers and lasers, as examples, can be made using the above method and side pump fibers.

Abstract: A method of forming an optical fiber tip, the method including, roughening at least part of an end portion of the optical fiber; and, etching the roughed end portion to thereby form an optical fiber tip.

Abstract: A method of forming a waveguide, the method comprising the steps of: forming a multilayer stack of light guiding layers; and delaminating the multilayer stack between at least two of the light guiding layers to form a waveguide between the light guiding layers; in which the patterned region has converging sides and the waveguide is tapered, the multilayer stack having increased transmissivity at a region corresponding to a selected thickness of the waveguide. A tapered waveguide is also disclosed, comprising: a multilayer stack of light guiding layers; the multilayer stack defining a channel between at least a first waveguiding layer and a second waveguiding layer; the channel having a diminishing thickness in a first direction; and at least one of the first waveguiding layer and the second waveguiding layer having a region of increased transmissivity adjacent a selected thickness of the core. Methods for the use of the tapered waveguide as an optical coupler or spectrometer are also disclosed.

Abstract: The invention relates to a tapered optical fiber and a method and drawing tower for producing such an optical fiber. The tapered optical fiber comprising a core region that is capable of guiding light along a longitudinal axis of said optical fiber and a cladding region surrounding said core region. The optical fiber comprises a tapered section arranged between a first longitudinal position and a second longitudinal position, said tapered section comprising a first taper section having a first length, L1, over which the optical fiber is tapered down to a taper waist, and a second taper section having a second length, L2, over which said optical fiber is tapered up.

Abstract: An optical combiner includes a plurality of input optical fibers, an output optical fiber, and a bridge fiber optically coupled to the plurality of input optical fibers and the output optical fiber. The bridge fiber includes a tapered portion whose outer diameter is reduced toward the emission end, and the outer diameter of the emission end face of the bridge fiber is smaller than the cladding outer diameter of the incident end face of the output optical fiber.

Abstract: A semiconductor pointed structure formed at an end portion of the core structure of a semiconductor photonic wire waveguide has a sloped side wall on at least one of the sides that constitute the pointed structure. The semiconductor pointed structure decreases in width and thickness towards the distal end. A method for fabrication of the structure is also disclosed.

Abstract: A polarization rotator assembly for rotating a polarization mode of an electromagnetic signal is provided. The polarization rotator assembly has a waveguiding structure of co-extensive first and second layers defining, successively, an input portion, a subwavelength composite portion and a polarization rotating portion. The subwavelength composite portion is formed by the first and second layers, where the second layer defines a subwavelength pattern. The polarization rotator portion is geometrically configured to rotate the polarization mode of the electromagnetic signal.

Abstract: Disclosed is a planar waveguide element including a first cylindrical lens disposed based on an z-axis and configured to collimate beams emitted from a plurality of emitters of a laser diode bar; a lens array configured to gather the beam emitted from each emitter via the first cylindrical lens; a plurality of first waveguides existing on an x-y plane by a number of the plurality of emitters and configured to gather at one place via a bending section; a taper configured to connect the lens array and each first waveguide, a width of the taper being narrower from the lens array to the plurality of first waveguide; and a combined waveguide configured to combine the plurality of first waveguides into one.

Abstract: A method for performing a multi-stage dilation of optical fibers is described, the method comprising performing successive dilation steps such that the adiabatic condition is maintained throughout the fiber. There is also described various optical devices employing such multi-stage dilated optical fibers, as well as methods of manufacture of the optical devices.

Abstract: An Ortho Mode Transducer (OMT) comprising a main guide configured with a set of ports and at both ends for communicating a band of frequencies. The ports and are placed at a predetermined distance from each other to form a taper section. Branching waveguides are disposed around the main guide for extracting polarization signals from the main guide. Coupling apertures are disposed apart along the periphery of the main guide for coupling the branching waveguides to the main guide. The coupling apertures are aligned parallel to a longitudinal axis of the main guide and extended to the taper portion of the main guide, which enhances bandwidth performance without the need for additional extraneous impedance matching elements.

Abstract: The present invention provides a small optical waveguide structure capable of converting the spot size of light, and capable of reducing the conversion loss when compared under the condition of the same waveguide length and performing an optical conversion with high efficiency. An optical waveguide structure (100) includes a base waveguide (110) including a taper section (111) whose width becomes continuously narrower from one side toward another side, and a narrow-width section (112) that is consecutively connected to a narrow-width side of the taper section (111) and extends toward the another side.

Abstract: An optical module providing higher reliability during high-speed light modulation and a lower bit error rate when built into a transmitter (transceiver). An optical module contains a taper mirror for surface emission of output light, an optical modulator device, and an optical modulation drive circuit, and the optical modulator device and the optical modulation drive circuit are mounted at positions so as to enclose the taper mirror.

Abstract: An optical waveguide structure may include a dielectric layer having a top surface, an optical waveguide structure, and an optical coupler embedded within the dielectric layer. The optical coupler may have both a substantially vertical portion that couples to the top surface of the dielectric layer and a substantially horizontal portion that couples to the optical waveguide structure. The substantially vertical portion and the substantially horizontal portion are separated by a curved portion.

Abstract: An optical fiber coupler connects transmission multicore optical fiber (TMCF) with an amplifier multicore optical fiber (AMCF) and a plurality of optical pump fibers. The coupler includes a plurality of signal cores extending between a multicore input endface and a coupler output endface, and a plurality of pump cores extending between a pump input and the coupler output endface. The multicore input endface is connectable to the TMCF, and the pump input is connectable to the optical pump fibers. Each pump core is paired with a corresponding signal core to form a core pair that is adiabatically tapered such that signal light carried by the signal core is combined with pump light carried by the pump core. The coupler output endface is connectable to the AMCF such that the combined light output of each core pair is provided as an input to a respective AMCF core.

Abstract: An optical assembly comprising (10) an optical coupler (12) defining a coupler first end section (18), a substantially opposed coupler second end section (20) and a coupler intermediate section (22) therebetween; a coupler passageway (24) extending in the coupler intermediate section (22) and also through at least a portion of the coupler second end section (20) and defining a passageway second end aperture (30) leading into the coupler passageway (24); a coupler peripheral surface (26) extending peripherally to the coupler passageway (24) in the coupler intermediate section (22); and a coupler lateral aperture (28) extending between the coupler passageway (24) and the coupler peripheral surface (26) in the coupler intermediate section (22). A first end optical fiber (14) is optically coupled to the optical coupler (12) in the coupler first end section (18) for allowing propagation of light between the optical coupler (12) and the first end optical fiber (14).

Abstract: There are provided an optical waveguide including: a substrate 1; a lower clad layer 2; a core pattern 3 with a taper in thickness direction; and an upper clad layer 4, the lower clad layer, the core pattern, and the upper clad layer being sequentially laminated on the substrate 1, in which the lower clad layer 2 has a cutting part 5. There also provided with an optical waveguide including: a substrate 1; a lower clad layer 2; a core pattern 3 with a taper in thickness direction; and an upper clad layer 4, the lower clad layer, the core pattern, and the upper clad layer being sequentially laminated on the substrate 1, in which the lower clad layer 2 has a dummy part on the top. These optical waveguides can secure alignment tolerance when connected with an optical element.

Abstract: A microresonator structure comprises a waveguide and a microsphere. The waveguide is of elongated cylindrical shape and includes a first section of optical transmission material and a cavity section axially aligned with the first section. The cavity section includes a first cavity and a second cavity. The first cavity is adjacent to the first section and includes a first sidewall of optical transmission material with an inner surface that tapers inward to an apex positioned adjacent to the first section. The second cavity is positioned adjacent to the first cavity of hollow cylindrical shape and includes a circumferential second sidewall of optical transmission material that abuts the first sidewall. The microsphere has a spherical outer surface and is positioned within the cavity section such that the outer surface contacts a portion of the first sidewall and a portion of the second sidewall.

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: Exemplary embodiments of an article of manufacture and method according to the present disclosure are provided. For example, a first multi-clad fiber arrangement can be provided that comprises a first core and at least one first cladding which is structured to propagate at least one first electro-magnetic radiation therethrough. A second multi-clad fiber arrangement can also be provided that comprises a second core and at least one second cladding which is structured to propagate at least one second electro-magnetic radiation therethrough. Further, at least one portion can be provided in which the first and second claddings are fused to one another.

Abstract: Devices and methods for visually confirming the positioning of a distal end portion of an illuminating device placed within a patient include inserting a distal end portion of an illuminating device internally into a patient, emitting light from the distal end portion of the illuminating device, observing transillumination resulting from the light emitted from the distal end portion of the illuminating device that occurs on an external surface of the patient, and correlating the location of the observed transillumination on the external surface of the patient with an internal location of the patient that underlies the location of observed transillumination, to confirm positioning of the distal end portion of the illuminating device.

Abstract: A leaky travelling wave array of optical elements provide a solar wavelength rectenna.

Abstract: A component for an optical probe, the component comprising: a tubular body defining an internal channel and an opening; a mounting ring which is mounted within the internal channel and configured to define an aperture aligned with the opening; and a window disposed across the aperture and bonded to the mounting ring around the aperture, wherein the window is diamond, wherein the mounting ring comprises a material having a coefficient of linear thermal expansion a of 14×10?6 K?1 or less at 20° C. and a thermal conductivity of 60 Wm?1K?1 or more at 20° C., and wherein the tubular body is made of a chemically inert material.

Abstract: A waveguide comprises an annular cross-section and a first numerical aperture (NA) at one end. The waveguide further comprises either an annular or circular cross-section at the other end, which has a second NA. The waveguide has a progressively-varying NA, which varies from the first NA (at one end) to the second NA (at the other end).

Abstract: An optical coupling element includes a first side surface and an upper surface. The upper surface defines a first cavity and a tapering hole which permits the insertion and precise fixing in place with adhesive of an optical fiber, without any gap or play in the attachment which would allow misalignment between the optical fiber and a light coupling lens.

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: Methods and systems for managing pulse energy scaling are disclosed, including generating electromagnetic radiation; coupling the electromagnetic radiation to a fiber geometrical management system comprising: a tapered fiber comprising: an elliptical or rectangular core centrally positioned within a single or double cladding shell, wherein the core comprises a fiber material and a doped gain medium; an input face wherein the doped core comprises a major axis and a minor axis, wherein the ratio of the major to minor axis at the input face ranges from about 1 to about 100; an output face wherein the doped core comprises a major axis and a minor axis, wherein the ratio of the major to minor axis at the output face ranges from about 1 to about 100; and wherein the major (minor) axis is adiabatically or linearly tapered from the input face to the output face. Other embodiments are described and claimed.

Abstract: The optical semiconductor device includes a spot-size converter formed on a semiconductor substrate. The spot-size converter has a multilayer structure including a light transition region. The multilayer structure includes a lower core layer, and an upper core layer having a refractive index higher than that of the lower core layer. The width of the upper core layer is gradually decreased and the width of the lower core layer is gradually increased in the light transition region. Both sides and an upper side of the multilayer structure are buried by a semi-insulating semiconductor layer in the light transition region. Light incident from one end section of the spot-size converter is propagated to the upper core layer. The light transits from the upper core layer to the lower core layer in the light transition region, is propagated to the lower core layer, and exits from the other end section thereof.

Abstract: A leaky travelling wave array of optical elements provide a solar wavelength rectenna.

Abstract: An novel fiber pump signal combiner is disclosed in which a fiber bundle array is coupled to a double-clad fiber with a taper section that is formed by etching a tapered outer surface into the cladding of a fiber rod to produce a high quality tapered outer surface free of defects with an inner core that has a constant diameter.

Abstract: The present invention provides a waveguide coupler configured to optically couple a strip waveguide to a first slot photonic crystal waveguide, wherein the slot photonic crystal waveguide has a lattice constant, an air hole diameter, a slot width and a first line defect waveguide width. The waveguide coupler includes a group reflective index taper having a second slot photonic crystal waveguide disposed between and aligned with the first slot photonic crystal waveguide and the strip waveguide. The second slot photonic crystal waveguide has a length, the lattice constant, the air hole diameter, the slot width, and a second line defect waveguide width that is substantially equal to the first line defect waveguide width adjacent to the first slot photonic crystal waveguide and decreases along the length of the second photonic crystal waveguide.

Abstract: An optical waveguide includes a body of optically transmissive material having a width substantially greater than an overall thickness thereof and including a first side, a second side opposite the first side, a central bore extending between the first and second sides and adapted to receive a light emitting diode, and extraction features on the second side. A light diverter extends into the central bore for diverting light into and generally along the width of the body of material. The extraction features direct light out of the first side and wherein at least one extraction feature has an extraction surface dimension transverse to the thickness that is between about 5% and about 75% the overall thickness of the body of material.

Abstract: There is described a double-clad fiber coupler (DCFC) composed of two double-clad fibers that have been fused together and tapered. The DCFC allows the propagation of light in the fundamental mode in its single-mode core with very little loss. Back reflected light may be collected two ways: by the core of the double-clad fiber and by the inner cladding of the double-clad fiber.

Abstract: A fiber coupler with an inner tube, an inner fiber arranged within the inner tube and several outer fibers arranged around the inner fiber, is disclosed, wherein said fiber coupler tapers in the longitudinal direction of the inner fiber from a main section to a terminal section and the inner cross section on the inner tube corresponds to the diameter of the inner fiber along the tapering section of the fiber coupler.