Abstract: An optical fiber with filtering thin film includes a first ferrule having a first through hole and a first contact surface. A first fiber is disposed into the first through hole, extending to the first contact surface. A first interface coupling material is between the first ferrule and the first fiber. A second ferrule has a second through hole and a second contact surface. A second fiber is disposed into the second through hole, extending to the second contact surface. A second interface coupling material is between the second ferrule and the second fiber. The first contact surface and the second contact surface are parallel and have an included tilt angle from a perpendicular transverse plane of first fiber. An optical filtering film is disposed between the first contact surface and the second contact surface. The first fiber and the second fiber are aligned.

Abstract: A three-dimensional ordered open-cellular structure. In one embodiment, the structure includes: a plurality of first truss elements defined by a plurality of first self-propagating polymer waveguides and extending along a first direction; a plurality of second truss elements defined by a plurality of second self-propagating polymer waveguides and extending along a second direction; and a plurality of third truss elements defined by a plurality of third self-propagating polymer waveguides and extending along a third direction. The first, second, and third truss elements interpenetrate each other at a plurality of nodes to form a continuous material, and the three-dimensional structure is self-supporting.

Abstract: An optical waveguide structure has excellent heat resistance and a low water absorbing property and can be manufactured with a low material cost. Such an optical waveguide structure includes: an optical waveguide having two surfaces, a core layer including core portions and cladding portions each having a refractive index lower than that of each of the core portions, the core layer having two surfaces, and cladding layers provided so as to make contact with the two surfaces of the core layer and having a refractive index lower than that of each of the core portions; and conductor layers provided on the two surfaces of the optical waveguide. In the optical waveguide structure, each of the cladding layers is formed of a norbornene-based polymer as a major component thereof.

Abstract: A method of manufacturing a biopolymer optical waveguide includes providing a biopolymer, unwinding the biopolymer progressively to extract individual biopolymer fibers, and putting the unwound fibers under tension. The tensioned fibers are then cast in a different polymer to form a biopolymer optical waveguide that guides light due to the difference in indices of refraction between the biopolymer and the different polymer. The optical fibers may be used in biomedical applications and can be inserted in the body as transmissive media. Printing techniques may be used to manufacture the biopolymer optical waveguides.

Abstract: A method for manufacturing multiple layers of waveguides is disclosed. Initially, a first cladding layer is deposited on a substrate, a first inner cladding layer is then deposited on the first cladding layer, and a first waveguide material is deposited on the first inner cladding layer. The first inner cladding layer and the first waveguide material are then selectively etched to form a first waveguide layer. Next, a second inner cladding layer followed by a second cladding layer are deposited on the first waveguide layer. The second inner cladding layer and the second cladding layer are removed by using a chemical-mechanical polishing process selective to the first waveguide material. A third inner cladding layer followed by a second waveguide material are deposited on the first waveguide material. The third inner cladding layer and the second waveguide material are then selectively etched to form a second waveguide layer.

Abstract: Waveguide apparatuses and methods are provided. A waveguide method (700) can include stacking (710) a plurality of layers (110) to form a plurality of waveguides (120). Each of the plurality of layers can include at least one waveguide surface (140). The method can further include aligning (720) the plurality of layers using at least one alignment device (160). The method can also include trapping (730) the aligned, stacked plurality of layers between a first member (170) and second member (180).

Abstract: The present invention provides an optical apparatus having a multimode interference coupler configured to optically couple a strip waveguide to a slot photonic crystal waveguide. The multimode interference coupler has a coupling efficiency to the slot photonic crystal waveguide greater than or equal to 90%, a width that is approximately equal to a defect width of the slot photonic crystal waveguide, a length that is equal to or less than 1.5 ?m, and interfaces with the slot photonic crystal waveguide at an edge of a period that gives a termination parameter of approximately zero. The optical apparatus may also include an insulation gap disposed between the multimode interference coupler and the slot photonic crystal waveguide, wherein the length of the multimode interference coupler is reduced by approximately one half of a width of the insulation gap.

Abstract: The present invention provides an electromagnetic wave resonator that is capable of showing surface wave resonance typically as outstanding plasmon resonance and can be manufactured industrially with excellent reproducibility and efficiency by combining currently available microprocessing technologies. The electromagnetic wave resonator of the present invention includes a first negative dielectric surface, a second negative dielectric surface and a positive dielectric thin film disposed between the first and the second negative dielectric surfaces. The positive dielectric thin film has an end face having an electromagnetic wave introduced therefrom. Intensity of the electromagnetic wave having a predetermined wavelength and being introduced from the end face is enhanced in the electromagnetic wave resonator due to resonance of a surface wave having an electric field component in a direction of film thickness of the positive dielectric thin film and without having a cut-off frequency.

Abstract: The invention provides stable lithium niobate waveguides, and systems and methods for making same. In accordance with one aspect of the invention, a waveguide includes a lithium niobate substrate having an upper surface; and a soft proton-exchanged layer embedded within the substrate, the soft proton-exchanged layer formed by exposing the lithium niobate substrate to a proton exchange solution including a proton exchange acid and a lithium salt of the proton exchange acid at a temperature of less than an atmospheric boiling point of the solution, followed by annealing the lithium niobate substrate under a vapor pressure of water preselected to inhibit protons in the substrate from forming water and evaporating from the upper surface of the substrate. The preselected water vapor pressure may be between 0.1 atm and about 0.9 atm, for example, between about 0.4 atm and about 0.6 atm, in one embodiment about 0.47 atm.

Abstract: In the production of optical devices or the like utilizing an intersubband transition of a coupled quantum well, a quantum well structure having strong coupling is provided. In addition, a coupled well structure of excellent productivity capable of avoiding thinning of coupling barrier layer for strengthening the coupling is provided. In the semiconductor coupled well structure of the present invention, a coupled quantum well structure disposed on the semiconductor single crystal substrate includes a coupling barrier layer 1a disposed between two or more quantum well layers 2a and 2b, wherein the coupling barrier layer 1a has an energy barrier that is smaller than an excitation level (E4 and E3) and is larger than a ground level (E2 and E1).

Abstract: Embodiments of the present invention are directed to multiplexer/demultiplexer systems. In one aspect, a multiplexer/demultiplexer system includes an input/output waveguide, two or more output/input waveguides, and a planar, non-periodic, sub-wavelength grating. The grating is configured so that when the system is operated as a multiplexer, each wavelength of light output from one of the two or more output/input waveguides is reflected by the grating toward the input/output waveguide. When the system is operated as a demultiplexer, each wavelength of light output from the input/output waveguide is reflected toward one of the two or more output/input waveguides.

Abstract: A method of making a ceramic waveguide delay line includes the step of providing several slices or slabs of dielectric material, each including a layer of metal material applied to respective opposed side surfaces thereof. The slices are then fired in an oven to fuse the layers of metal material to the slices. The slices are then stacked together to form a core which is then dried and subsequently fired. An area of metal material is applied to the outer surface of the core. The core is subsequently dried and fired in an oven.

Abstract: An optical grating comprising a grating layer and two surface layers, the layers being arranged with the grating layer between the surface layers. The grating layer comprises a set of multiple, discrete, elongated first grating regions that comprise a first dielectric material and are arranged with intervening elongated second grating regions. The bulk refractive index of the dielectric material of the first grating regions is larger than the bulk refractive index of the second grating regions. The first surface layer comprises a first impedance matching layer, and the second surface layer comprises either (i) a second impedance matching layer or (ii) a reflective layer. Each said impedance matching layer is arranged to reduce reflection of an optical signal transmitted through the corresponding surface of the grating layer, relative to reflection of the optical signal in the absence of said impedance matching layer.

Abstract: An optical interconnect device includes a first substrate, a second substrate, an optical waveguide, an electrical wiring and a switching device. The first substrate has an electrical wiring circuit, an electrical-optical converter for converting an electrical signal to an optical signal, and a light emitting device for emitting a light. The second substrate has an electrical wiring circuit, an optical-electrical converter for converting the optical signal to the electrical signal, and a light receiving device for receiving the light from the light emitted device. The optical waveguide optically connects the light emitting and light receiving devices. The electrical wiring electrically connects the electrical wiring circuits of the first and second substrates. The switching device determines a fast signal of data to be transmitted via the optical substrate and a slow signal of data to be transmitted via the electrical wiring.

Abstract: A single-mode, etched facet distributed Bragg reflector laser includes an AlGaInAs/InP laser cavity, a front mirror stack with multiple Fabry-Perot elements, a rear DBR reflector, and a rear detector. The front mirror stack elements and the rear reflector elements include input and output etched facets, and the laser cavity is an etched ridge cavity, all formed from an epitaxial wafer by a two-step lithography and CAIBE process.

Abstract: A diffractive beam expander (50) comprises an input grating (10), a crossed grating (20), and an output grating (30) implemented on a planar transparent substrate (7). The crossed grating (20) comprises a plurality of diffractive features (23) arranged along the lines of a first set of parallel lines (25) and along the lines of a second set of parallel lines (26) such that the lines (25) of the first set are parallel to the lines (26) of the second set. The lines of the first set have a first grating period and the lines of the second set have a second grating period. A light beam (B1) coupled into the substrate (7) by the input grating (10) impinges on the crossed grating (20) at a first location (EC1) and further locations (EC2). Interaction at the first location (EC1) provides several sub-beams (S00, S01, S10) which propagate in different directions.

Abstract: Consistent with the present disclosure, a non-adiabatic polarization rotator is provided that can rotate the polarization of an incoming over a relatively short length. Light is supplied to the polarization rotator via a polarizer, which insures that the optical input to the polarization polarization rotator has a desired polarization. Preferably, the polarization rotator has a structure that is readily implemented with semiconductor materials and can be fabricated with known processing techniques. In addition, the polarization rotator and polarizer may include similar materials and/or layers, such that both may be readily integrated on a common substrate, such as an indium phosphide (InP) substrate.

Abstract: Techniques are disclosed for efficiently fabricating semiconductors including waveguide structures. In particular, a two-step hardmask technology is provided that enables a stable etch base within semiconductor processing environments, such as the CMOS fabrication environment. The process is two-step in that there is deposition of a two-layer hardmask, followed by a first photolithographic pattern, followed by a first silicon etch, then a second photolithographic pattern, and then a second silicon etch. The process can be used, for example, to form a waveguide structure having both ridge and channel configurations, or a waveguide (ridge and/or channel) and a salicide heater structure, all achieved using the same hardmask. The second photolithographic pattern allows for the formation of the lower electrical contacts to the waveguides (or other structures) without a complicated rework of the hardmask.

Abstract: A spot-size converter is equipped with a substrate, a clad that is formed on the substrate, a core that is embedded inside the clad, and an input/output end face. The core is tapered toward the input/output end face along a light propagation direction. In the clad, groove portions that expose a substrate face are formed extending as far as the input/output end face and on both sides of the core along the light propagation direction.

Abstract: An opto-electric hybrid board in which a new alignment mark having an identifying mark that is easy to recognize is formed in addition to a conventional alignment mark, and a method of manufacturing the opto-electric hybrid board. The opto-electric hybrid board includes an optical waveguide portion 2, an electric circuit board 1, and optical elements mounted on this electric circuit board 1. The optical waveguide portion 2 includes a translucent under cladding layer 21, a linear core 22 for an optical path, first alignment marks 24 positioned relative to end portions of this core 22, and an over cladding layer 23 for covering the above-mentioned core 22 and the first alignment marks 24. The electric circuit board 1 includes second alignment marks 15 for positioning of the optical elements and formed on a surface thereof on which the optical elements are mounted.

Abstract: A three-dimensional sensor optical waveguide which permits size reduction, and a three-dimensional sensor employing the same. A three-dimensional sensor optical waveguide includes a plurality of frame-shaped optical waveguide members stacked coaxially in a thickness direction, and a measurement space defined by inner spaces of the stacked frame-shaped optical waveguide members. The optical waveguide members each include a light emitting core, a light receiving core and an over-cladding layer covering the cores. The light emitting core has a light output end positioned in one of opposed inner edge portions of each of the frame-shaped optical waveguide members. The light receiving core has a light input end positioned in the other inner edge portion of each of the frame-shaped optical waveguide members.

Abstract: A light emitting sign including a lightguide having a thickness not greater than 0.5 millimeters. The lightguide having an array of elongated legs extending therefrom, wherein each leg terminates in a bounding edge and is folded such that the bounding edges are stacked. At least one light source emits light into the stacked bounding edges. The light travels within the legs to the lightguide, with the light from each leg combining and totally internally reflecting within the lightguide. A plurality of light scattering features frustrate totally internally reflected light within the lightguide such that the light exits the sign in a light emitting area.

Abstract: A position adjustment device for an integration rod includes a fixed plate, two resilient members, and two adjusting screws. The first resilient member is positioned between the fixed plate and the rod for exerting an elastic force on the rod in a first direction, and the second resilient member is positioned between the fixed plate and the rod for exerting an elastic force on the rod in a second direction different from the first direction. The first adjusting screw is inserted through the part of the housing and has a first end surface that presses against one side surface of the rod opposite the first resilient member. The second adjusting screw is inserted through the part of the housing and has a second end surface that presses against one side surface of the rod opposite the second resilient member. The first and the second end surface are arc surfaces.

Abstract: The present invention provides an optical sheet having a plurality of light guide plate patterns, each light guide plate pattern having a micro-patterned output surface for emitting light, and a micro-patterned bottom surface opposing to the output surface.

Abstract: A two-dimensional photonic crystal according to the present invention includes a first layer having a dielectric first layer slab in which first layer holes having a refractive index lower than that of the first layer slab are arranged cyclically, a second layer formed on the first layer, including dielectric columns having a refractive index higher than the air arranged in the air with the same cycle as the first layer hole, and a third layer having a dielectric third layer slab in which third layer holes having a refractive index lower than that of the third layer slab are arranged cyclically. Thus, it is possible to obtain the two-dimensional photonic crystal that can create a wider complete PBG than before regardless of the polarization of light and can be manufactured easily.

Abstract: Provided are an optical waveguide and a production method thereof which can constrict both the width and thickness of the SOI optical waveguide core layer in the same process and at the same time, simplify production process, and reduce optical losses. An optical waveguide includes a first clad layer formed on a semiconductor substrate; a first core layer formed on the upper side of the first clad layer with the use of a semiconductor material the refractive index of which is higher than that of the first clad layer; and a second clad layer formed on the upper side of the first core layer with the use of a material the refractive index of which is lower than that of the first core layer. The width of the first core layer is defined based on the width of an unoxidized semiconductor material sandwiched between oxide films the parts of which are thermally oxidized.

Abstract: A collector for propagating incident radiation is disclosed. The collector may comprise a light directing component coupled to a buffer component, a first propagation component coupled to the buffer component and configured to transmit the incident radiation into a collector region through one of a plurality of windows, and an optical transport assembly coupled to an end of the collector region and having a second propagation component. Each light directing component may be configured to redirect the incident radiation from a first direction to a second direction, and the collector region may include a plurality of regions exhibiting a refractive index value that gradually transitions from about 1.5 to about 2.0. The second propagation component may be further configured to retain the incident radiation.

Abstract: The present invention includes a device and a method for fabricating a device that is an optical power mode transformer that accepts light in a mode transformation direction where the transformer is attached to or embedded in a semiconductor microchip and includes a first single or multimode optical input (SM) waveguide including a first core surrounded by a cladding, and, a second high contrast index grade (HC) waveguide including a second core having a tapered region and surrounded by said cladding, a portion of the tapered region of the core being embedded within the first optical input waveguide region with an embedded length sufficient for efficient light transfer from the first input waveguide to the said second waveguide wherein the embedded portion of the tapered region is fully surrounded by the first input waveguide along an axial and radial cross-section of the second waveguide in the mode transformation direction.

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: Optical devices for guiding illumination are provided each having a body of optical material with staircase or acutely angled ramp structures on its top surface for distributing light inputted from one end of the device from the front exit faces of such structures along certain angular orientations, while at least a substantial portion of the light is totally internally reflected within the body until distributed from such front exit faces. Optical devices are also provided each have a body of optical material having a bottom surface with acutely angled ramp structures and falling structures which alternate with each other, such that light is totally internally reflected within the device until reflected by such ramp structures along the bottom surface to exit the top surface of the device or transmitted through the ramp structures to an adjacent falling structure back into the device.

Abstract: In order to provide a method of efficiently manufacturing an optical waveguide core having an endface inclined at a predetermined angle, the following method of manufacturing an optical waveguide core is employed.

Abstract: An optical circuit comprises: a first waveguide; a second waveguide: and a third waveguide that converts mode field and direction of polarization of light of said first waveguide at the same time to perform wave guiding to said second waveguide: wherein large aspect ratio directions of corresponding ends of a core of said first waveguide and a core of said second waveguide differ from each other.

Abstract: An optical waveguide device includes: a substrate having an electro-optical effect; an optical waveguide section formed on the substrate; and a plurality of modulating electrodes for modulating optical waves propagating in the optical waveguide section. The optical waveguide section branches into two parts in the propagating direction of the optical waves, thus forming the two main optical waveguides, and each of the main optical waveguides branches into two parts in the propagating direction of the optical waves, thus forming the two sub optical waveguides. The two main optical waveguides constitute a main Mach-Zehnder type optical waveguide, and the two sub optical waveguides are incorporated into the main Mach-Zehnder type optical waveguide to constitute a sub Mach-Zehnder type optical waveguide. A heat conduction suppressing zone is defined on a portion of the substrate disposed between two opposite sub Mach-Zehnder type optical waveguides.

Abstract: An information recording apparatus has a plurality of fine particles forming an array on a plane in close proximity of each other, each of the plural particles including a ferromagnetic metal, a light-emitting device for exciting a near-field light, and a photo-electric conversion element for detecting a near-field light traveled along the fine particles. Summary information may be recorded for plural information recording parts.

Abstract: An enhanced wavelength-converting structure is disclosed. The enhanced wavelength-converting structure includes a substrate, a wavelength-converting layer arranged next to the substrate, and a wavelength-selective reflecting layer arranged next to the wavelength-converting layer. The wavelength-converting layer converts the first light into the second light. A part of the second light radiating backward to the light source is further reflected toward the substrate by the wavelength-selective reflecting layer to form the enhanced second light by combining with another part of the second light radiating toward the substrate.

Abstract: A high-index contrast waveguide component is presented, which is based on the fast changing of the transmission properties of an optical waveguide by applying electric voltages, or by embossing electric currents. The waveguide consists of a high-refractive waveguide core surrounded by a low-refractive surrounding material, which at least area by area has electro-optical properties. By applying a voltage to completely or partially optically transparent electrodes, an electric field is generated having a strong overlap with the optical mode, being in interaction with it, and therefore changing the transmission properties of the waveguide. The transparent electrodes or supply line areas are laminar, connected at low resistance with conductor paths of high conductivity by means of structures continually repeated along the propagation direction. Thus, it is possible for example to very fast load the capacity being effective between the electrodes, and to thus achieve a high electric band width.

Abstract: A method comprises a first multilayer body forming step of forming a first multilayer body on a first cladding layer, the first multilayer body including a core layer and a first polishing stop layer in order from the first cladding layer side; a first multilayer body patterning step of pattering the first multilayer body, so as to expose the first cladding layer about the patterned first multilayer body; a second multilayer body forming step of forming a second multilayer body on the exposed first cladding layer and patterned first multilayer body, the second multilayer body including a second cladding layer and a second polishing stop layer in order from the first cladding layer side; and a removing step of polishing away a part of the second multilayer body formed on the first multilayer body.

Abstract: Embodiments of an optical device, an array of optical devices, and a technique for fabricating the optical device or the array are described. This optical device is implemented using two semiconductor layers (such as silicon), one of which includes a heater and the other includes a thermally tunable optical waveguide. Spatially separating these two functions in the optical device results in more efficient heat transfer between the heater and the optical waveguide, reduced heat transfer to the surroundings, and reduced optical losses in the optical waveguide relative to existing silicon-based optical devices.

Abstract: A material for an optical circuit-electrical circuit mixedly mounting substrate comprises a light permeable resin layer, and an optical circuit forming layer that is made of a light permeable resin of which refractive index increases (or decreases) when irradiated with an activating energy beam and is disposed adjacent to the light permeable resin layer, wherein a refractive index of a portion of the optical circuit forming layer is higher (or lower) than that of the light permeable resin layer when the material for the optical circuit-electrical circuit mixedly mounting substrate is irradiated with an activating energy beam so that said portion is irradiated.

Abstract: An optical waveguide having a core region with a substantially rectangular cross-section with a selected aspect ratio of width to height. Embodiments include devices incorporating the optical waveguide and methods for using the optical waveguide.

Abstract: A lumenaire for mixing and emitting light from multiple light sources which has at least one first light source of a particular type and at least one second light source of a differing type. There is an optical system which includes at least one individual light collecting optical element at least partially surrounding each light source. There is a substantially planar light guide that receives and transports the light from each of the individual optical elements and optically mixes and emanates the light from both types of light sources simultaneously, through a common surface of the planar light guide. The planar light guide is segmented and the segmented sections are angularly disposed, in section in relationship to each other and the individual optical elements project light into at least one of the segments.

Abstract: An apparatus for optically coupling light between optical transmission components is provided. The apparatus includes first and second optical transmission components wherein the first optical transmission component includes a planar optical waveguide, a grating coupler, and a transparent substrate and the second optical transmission component includes an optical fiber. Preferably, the planar optical waveguide includes silicon and the transparent substrate includes glass. Methods for coupling light between optical transmission components are also provided.

Abstract: Optical waveguides using segmented periodically-spaced high contrast gratings bounding a hollow core propagation region on at least two sides. Incident light is received in a hollow waveguide (HW) region (core) between opposing HCG faces which provide lateral confinement in response to glancing reflections of the incident light beam from high refractive index segments of the HCG as it traverses the core. Embodiments are described for planar waveguides (1D) having a planar core between two planar HCGs, as well as 2D waveguides, such as having rectangular segments of the HCG through which light is propagated. Additionally, other configurations of HCG-HW, including those having arbitrary incidence and azimuth, angled HCG segments, propagation in a direction which is transverse, or alternatively parallel, to the segments of the HCG.

Abstract: Photonic detection systems and methods are shown. A flow through photonic membrane is provided with pores which are distributed along multiple regions. The pores of one region have walls to which a first type of target specific anchor can be attached, while pores of another region have walls to which a second type of target specific anchor can be attached. An additional region of pores without anchors can be provided, so that optical detection occurs differentially. A stack of photonic membranes is also provided. The diameter of the pores of one photonic membrane is larger than the diameter of the pores of another photonic membrane, thus allowing also determination of the size of a target organism flown through the stack of membranes.

Abstract: Embodiments in accordance with the present invention provide waveguide structures and methods of forming such structures where core and laterally adjacent cladding regions are defined. Some embodiments of the present invention provide waveguide structures where core regions are collectively surrounded by laterally adjacent cladding regions and cladding layers and methods of forming such structures.

Abstract: An optical device includes an electrooptic crystal substrate, a polarization-inverted region formed in a part of the electrooptic crystal substrate, an optical waveguide formed in the electrooptic crystal substrate, and a groove for relaxing stress disposed between a domain wall of the polarization-inverted region and the optical waveguide.

Abstract: A light extraction film having internal nanostructures and external microstructures for organic light emitting diode (OLED) devices. The light extraction film includes a flexible substantially transparent film, a low index nanostructured layer applied to the film, and a high index planarizing backfill layer applied over the nanostructured layer. External optical microstructures are applied to the flexible substantially transparent film on a side opposite the nanostructured layer to enhance light extraction from the OLED devices while providing for a more uniform luminance distribution.

Abstract: The present invention provides a method for manufacturing an optical waveguide. The inventive method includes steps of providing a transfer member comprising a transfer sheet and a first metal film. The transfer sheet and the first metal film are detachable from each other. A laminated body made of a core layer disposed between two clad layers is formed on the transfer member. The invention also relates to optical waveguides produced by the inventive process and devices incorporating the optical waveguides of the invention.

Abstract: An optical waveguide structure including a III-V semiconductor substrate, a III-V semiconductor top layer, and an etch stop layer sandwiched therebetween, the etch stop layer containing aluminium and phosphorous, the top layer including first and second spaced apart recesses extending through the top layer to the etch stop layer and defining an optical waveguide therebetween. Also a method of manufacture of an optical waveguide structure including the steps of: providing a multilayer semiconductor wafer including a III-V semiconductor substrate, a III-V semiconductor top layer and an etch stop layer sandwiched therebetween, the etch stop layer including aluminium and phosphorous; and etching through the top layer to the etch stop layer by use of a dry etch containing chlorine to provide two spaced apart recesses defining the optical waveguide therebetween.

Abstract: An optical multiplexing device includes an optical element having at least one set of diffractive elements, and an optical reflector. The reflector routes, between first and second optical ports, that portion of an optical signal transmitted by the diffractive element set. The diffractive element set routes, between first and multiplexing optical ports, a portion of the optical signal that is diffracted by the diffractive element set. More complex optical multiplexing functionality(ies) may be achieved using additional sets of diffractive elements, in a common optical element (and possibly overlaid) or in separate optical elements with multiple reflectors. Separate multiplexing devices may be assembled with coupled ports for forming more complex devices. The respective portions of an optical signal transmitted by and reflected/diffracted from the diffractive element set typically differ spectrally.