Abstract: Disclosed are methods and apparatus using frequency-selected electromagnetic inversion to obtain sub-surface geophysical characteristics. One embodiment relates to a computer-implemented method for inverting an electromagnetic geophysical data signal to obtain an earth response. The method involves computing uncertainties associated with an electromagnetic geophysical data signal and selecting subset of frequencies based on the uncertainties. The electromagnetic geophysical data signal may then be inverted for the subset of the frequencies to determine the earth response. Other embodiments, aspects, and features are also disclosed.

Abstract: Neutron activation measurement techniques may be used to evaluate various properties of a subterranean well structure. In an example implementation, a logging tool can be positioned within a wellbore, such that neutrons generated by a neutron source are directed towards well structure. In response to the neutrons, the well structure emits gamma rays. A portion of the gamma rays can be detected by a gamma detector. To enhance the well structure's response to neutron activation, the well structure can be constructed of materials that include one or more doping materials. The inclusion of these doping materials can increase the number of gamma rays that are emitted when neutrons are directed into the well structure, and these emitted gamma rays can be more easily identified based on their energy level.

Abstract: An apparatus for providing a signal indicative of a property of an earth formation includes: a carrier conveyable through a borehole; a neutron source disposed on the carrier and configured to emit neutrons into the earth formation; a radiation detector disposed on the carrier and configured to detect radiation from the earth formation due to interaction of emitted neutrons with the earth formation and to provide the signal indicative of the property; and a neutron shield configured to shield the radiation detector from emitted neutrons that did not interact with the earth formation; wherein the radiation detector shield includes a glass ceramic material having a plurality of nano-crystallites, each nano-crystallite in the plurality having a periodic crystal structure with a diameter or dimension that is less than 1000 nm that includes Li and/or Boron and a rare-earth element that have positions in the periodic crystal structure of each nano-crystallite.

Abstract: A method for estimating at least one geological constituent may include obtaining a measured energy spectrum for the at least one geological constituent for a first borehole configuration, generating a calculated energy spectrum for the at least one geological constituent for the first borehole configuration, and generating a calculated energy spectrum for the at least one geological constituent for a second borehole configuration different than the first borehole configuration. The method may further include determining a relationship between the calculated energy spectra for the first and second borehole configurations, and generating an estimated energy spectrum for the at least one geological constituent for the second borehole configuration based upon the measured energy spectrum and the relationship between the calculated energy spectra for the first and second borehole configurations.

Abstract: A system includes a light source and a nonlinear converter optically coupled to and remote from the light source. The nonlinear light converter converts a light pulse received from the light source to a broadened or spectrum-shifted light pulse. The system also includes a sensor in situ with the nonlinear light converter. The sensor performs a sense operation based on the broadened or spectrum-shifted light pulse and generates an electrical signal corresponding to the sense operation. The system also includes an electro-optical interface in situ with the sensor that transforms the electrical signal to an optical signal for conveyance to a signal collection interface.

Abstract: A downpipe sensor detects single grains in a downpipe. A transmitting unit and a receiving unit are spaced apart across a measurement field. Light beams emitted by the transmitting unit are guided in the case of free beam path through the downpipe interior to the receiving unit and are attenuated during a passage of a grain. The receiving unit is a line element with a predefined number of receiving elements. The transmitting unit has light-emitting diodes with perforated screens and a reflector element in the form of a right triangular prism. Light is emitted from the diodes transversely to a receiving axis of the receiving unit, bundled via the perforated screens, guided into the reflector element, deflected by total reflection toward a exit surface to form a light band of parallel light beams. The light band illuminates the entire measurement field with even intensity.

Abstract: There is provided a fixed snow measuring plate, the snow measuring plate that is fixed to the ground and is provided on the land to be disposed in a lower part of one end of an instrument tower in which a sensor for observing drifted snow is installed, wherein the snow measuring plate is installed such that a position thereof is fixed to the ground.

Abstract: Described herein are copolymers constructed from chiral, non-racemic monomers, which self-assemble to photonic crystals. The difficulty of incorporating chiral elements into photonic crystals has limited the ability to generate unique bandstructures for different circular polarizations of light. The materials and methods described herein relate to easily, predictably fabricating chiral photonic crystals having desirable optical properties.

Abstract: The problem of the present invention is to overcome drawbacks of conventional optical filters such as near-infrared cut filters and to provide an optical filter which generates little scatted light even during light absorption and has excellent transmittance property. The optical filter of the present invention is characterized by containing a squarylium-based compound and a compound which absorbs or quenches fluorescence of the squarylium-based compound. The optical filter of the present invention preferably contains a near-infrared absorbing dye containing a squarylium compound (A) and at least one compound (B) selected from the group consisting of a phthalocyanine-based compound (B-1) and a cyanine-based compound (B-2).

Abstract: A method for producing a polarizer comprises the steps of: (A) stretching a polyvinyl alcohol-based resin layer to obtain a stretched layer; (B) immersing the stretched layer in a dyeing liquid containing iodine to obtain a dyed layer in which absorbance thereof determined from a tristimulus value Y is from 0.4 to 1.0 (transmittance T=40% to 10%); and (C) removing a part of iodine adsorbed in the dyed layer so that the absorbance of the dyed layer decreases by 0.03 to 0.7, provided that the absorbance of the dyed layer is controlled so that it does not become less than 0.3.

Abstract: An exemplary method for making a light blocking plate includes the steps of providing a flat plate-like light pervious member; forming a plurality of spaced ceramic power layers on the light pervious member; forming a light blocking layer over the light pervious member and side faces of the ceramic power layers; forming an electromagnetic shielding layer over the light blocking layer; removing top portions of the ceramic power layers with remaining portions of the ceramic power layers thus exposed; and removing the remaining portions of the ceramic power layers.

Abstract: An infrared-transmitting film which is excellent in mechanical strength and environmental resistance. The infrared-transmitting film comprises a buffer layer formed on a surface of an infrared optical substrate and having a Vickers hardness greater than that of the substrate and an environmental resistance improving layer provided in contact with the buffer layer and having a Vickers hardness greater than that of the buffer layer.

Abstract: Optical films, and organic light-emitting display devices employing the same, include a high refractive index pattern layer including a lens pattern region and a non-pattern region alternately formed, wherein the lens pattern region includes a plurality of grooves each having a depth larger than a width thereof, and the non-pattern region has no pattern; and a low refractive index pattern layer formed of a material having a refractive index smaller than a refractive index of the high refractive index pattern layer, wherein the low refractive index pattern includes a plurality of filling portions filling the plurality of grooves.

Abstract: The present invention provides a method of forming a nano-pattern on a surface of a lens, which comprises steps of: (i) filling a conductive material in an space between a lens and a substrate; (ii) applying a first coating solution to the surface of the lens filled with the conductive material by to a wet process; (iii) forming a nano-pattern on the surface of the lens on which the first coating solution is applied by performing a reactive ion etching process; and (iv) removing the first coating solution remaining on the lens surface and the conductive material filling in the space between the lens and the substrate. The lens of the present invention is a functional lens with low reflectance, high transmittance and super water-repellency owing to a functional coating layer, thereby replacing the conventional lens on which an anti-reflective coating is formed.

Abstract: A method is provided for producing an article which is transparent to infrared radiation. The method includes the steps of (a) disposing a plurality of nanoparticles on a substrate, wherein said nanoparticles comprise a metal sulfide or a metal selenide; (b) subjecting the nanoparticles to spark plasma sintering, thereby producing a sintered product; and (c) removing the sintered product from the substrate as a self-supporting mass.

Abstract: A device is provided, which includes at least one optical area sensor having an optical semiaxis and an entrance pupil. The device also includes an optical element including at least one pair of parallel surfaces. The device is characterized in that the optical element has a refractive index which decreases as the distance from the center increases at least along a direction in parallel to the surfaces at least between one edge of the optical element and a center of the optical element. The optical element is situated with respect to the area sensor in such a way that the surfaces are situated perpendicularly to the optical semiaxis. The increase of the refractive index perpendicular to the optical semiaxis makes it possible to situate the optical element having the parallel surfaces perpendicular to the optical semiaxis, so that the block requires minimal installation space.

Abstract: Systems and methods reduce temperature induced drift effects on a liquid lens used in a vision system. A feedback loop receives a temperature value from a temperature sensor, and based on the received temperature value, controls a power to the heating element based on a difference between the measured temperature of the liquid lens and a predetermined control temperature to maintain the temperature value within a predetermined control temperature range to reduce the effects of drift. A processor can also control a bias signal applied to the lens or a lens actuator to control temperature variations and the associated induced drift effects. An image sharpness can also be determined over a series of images, alone or in combination with controlling the temperature of the liquid lens, to adjust a focal distance of the lens.

Abstract: A rigid deformable reflector for heating a target, the rigid deformable reflector having a reflective surface capable of being rigidly deformed, a backing surface capable of supporting the reflective surface, and a concave shape. A method of deforming a rigid deformable reflector utilizing a deforming mechanism, wherein the rigid deformable reflector has a reflective surface and the deforming mechanism has a base and an actuator, the method having the steps of: placing a rigid deformable reflector onto the deforming mechanism, and activating the actuator thereby causing a first force to be applied to the rigid deformable reflector and deforming the shape of the rigid deformable reflector beyond its elastic limit.

Abstract: Low density mirrors for optical assemblies and methods of manufacture thereof. In one example, a reflective mirror is formed of a magnesium or magnesium alloy substrate that is single point diamond turned to provide a reflective surface. The magnesium or magnesium alloy substrate is compatible with thin-film finishing processes and/or magnetorheological finishing which may be applied to improve a surface finish of the mirror.

Abstract: A mirror (1a; 1a?; 1b; 1b; 1c; 1c?) with a substrate (S) and a layer arrangement configured such that light (32) having a wavelength below 250 nm and incident on the mirror at at least an angle of incidence of between 0° and 30° is reflected with more than 20% of its intensity. The layer arrangement has at least one surface layer system (P??) having a periodic sequence of at least two periods (P3) of individual layers, wherein the periods (P3) include a high refractive index layer (H??) and a low refractive index layer (L??). The layer arrangement has at least one graphene layer. Use of graphene (G, SPL, B) on optical elements reduces surface roughness to below 0.1 nm rms HSFR and/or protects the EUV element against a radiation-induced volume change of more than 1%. Graphene is also employed as a barrier layer to prevent layer interdiffusion.

Abstract: A step prismatic retro-reflector includes a main reflective corner having a shared reflective surface of a geometric single plane, a virtual step surface coming into contact with the shared reflective surface at a right angle, and a plurality of sub reflective corners. Each reflective corner has a pair of independent reflective surfaces coming into contact with each other at a right angle, and arranged along the step surface, wherein the retro-reflector elements are arranged to be alternated such that a corner ratio (l/w) of the sub reflective corners is 1.5 or more, a corner orientation of the main reflective corner deviates at an angle of 10 degrees or more with respect to a point of tangency of an incident plane, a reflection orientation thereof deviates at an angle within 10 degrees, and the corner orientations thereof deviate in the opposite direction to each other.

Abstract: A process for positive microcontact printing, including inking a patterned mold with a thiol; contacting the mold with a metal surface of a substrate; backfilling the metal surface with a solution containing an aromatic amine to form a backfilling layer; etching the metal surface of the substrate; and rinsing the substrate to remove the backfilling layer.

Abstract: The present invention provides a color filter substrate and a manufacturing method thereof, an organic electroluminescent display panel and a display device. The color filter substrate of the present invention comprises a first base, and a plurality of color filters and black matrixes arranged on the first base, wherein two adjacent color filters are at least partially overlapped, and each black matrix is at least partially arranged at the overlapped position of the two adjacent color filters; and the color filter substrate further comprises a first adhesive layer for eliminating section differences between the adjacent color filters or between the color filters and the black matrixes, and the first adhesive layer is provided with scattering particles therein. The color filter substrate can be used in the organic electroluminescent display panel.

Abstract: A display device includes a display panel, a backlight unit and a color conversion layer. The color conversion layer includes light emitting particles and metal particles. The light emitting particles are configured to receive a first light and to generate a second light having a wavelength different from the first light. The metal particles are configured to receive the first light or the second light and to cause a surface plasmon resonance.

Abstract: An article has optical structures disposed on a base material element. The optical structures include lenticular lens structures and discrete coloring elements having distinct color regions. The lenticular lens structure has several lens layers. The lenticular lens structure may have any of a variety of cross-sectional shapes. The article has a different appearance when an observer views the article at various angles. The appearance may differ in terms of coloring scheme.

Abstract: A color filter comprising a cured layer of a photosensitive resist composition comprising a highly reactive polyacrylate monomer and a process for the preparation thereof are provided. The color filter is especially useful for low temperature applications such as electrophoretic displays, polymer dispersed liquid crystal displays, OLED devices and the like.

Abstract: An infrared filter includes a transparent substrate, and an infrared-filtering multilayer film. The infrared-filtering multilayer film is coated on the transparent substrate, and the infrared-filtering multilayer film includes a plurality of the first kind of film layers, a plurality of the second kind of film layers, a plurality of the third kind of film layers and a plurality of the fourth kind of film layers, wherein the four kinds of film layers are arranged in order of gradient refractive indexes. At least two kinds of film layers are made of composite materials.

Abstract: Provided is a method capable of producing an optically anisotropic laminated body in which defects are hardly generated so that light leakage is scarcely caused. This method is a method for producing an optically anisotropic laminated body including a substrate, an oriented film, and an optically anisotropic film, and has steps of: applying, to a surface of the substrate, an oriented-film-forming composition including an oriented-film-forming material and a solvent and having a viscosity of 4 mPa·s or less at 25° C., and drying the resultant to form the oriented film; and then applying, onto the resultant oriented film, an optically-anisotropic-layer-forming composition including a polymerizable liquid crystal compound, and drying the resultant to orient the polymerizable liquid crystal compound vertically to the surface of the substrate to form the optically anisotropic film.

Abstract: A reflective film includes interior layers arranged to selectively reflect light by constructive or destructive interference, the layers extending from a first zone to a second zone of the film. The film has a first thickness and the interior layers provide a first reflective characteristic in the first zone; the film has a second thickness and the interior layers provide a second reflective characteristic in the second zone. The difference between the first and second reflective characteristics is not substantially attributable to any difference between the first and second thicknesses, which difference may be zero. Rather, the difference in the reflective characteristics is substantially attributable to reduced birefringence of at least some of the interior layers in one zone relative to the other zone. The film may also incorporate absorbing agents to assist in the manufacture or processing of the film. Related methods and articles are also disclosed.

Abstract: A quantum dot container may include a body having a cavity and a phosphor disposed inside the cavity. The body may include a light transmitting portion and a bent portion connected to one end of the light transmitting portion and extending at a predetermined angle with respect to an extension direction of the light transmitting portion.

Abstract: A light guide element and a lighting fixture are described. The light guide element includes a light guide body, first microstructures and second microstructures. The light guide body includes a first light-emitting surface and a second light-emitting surface opposite to and parallel to each other. The first microstructures are disposed on the first light-emitting surface in rows. The second microstructures are respectively corresponding to the first microstructures and are disposed on the second light-emitting surface. In each of the rows, each of the first microstructures laps over the corresponding second microstructure in part in a normal direction of the first light-emitting surface. Overlapping ratio of the first microstructures and the corresponding second microstructures become greater from one end of one of the rows to the other end of the one of the rows.

Abstract: An illumination apparatus includes a light source that emits light, a light guide member that has a base end surface onto which the light emitted from the light source is incident and a tip surface which is an opposite end surface to the base end surface, and guides the light from the base end surface towards the tip surface, and an attachment member that has a light shield property and an opening corresponding to a shape of the light guide member and accommodates the light guide member in the opening. The light guide member is curved so that a distance between the light guide member and the opening is gradually increased towards the tip surface-side in a longitudinal direction of the light guide member.

Abstract: A light guide element and a light source device using the same are provided. The light guide element has a main body. The main body has a hollow portion with a cone shape and a microstructure pattern formed on the main body. The cone-shaped hollow portion has a bottom portion and a top portion. The bottom portion is located on the bottom surface of the main body, and has a first hollow cross section area. The top portion is opposite to the bottom surface, and has a second cross section area smaller than the first cross section area. The microstructure pattern includes high-density areas and low-density areas to improve a light distribution caused by the cone-shaped hollow portion. The light source device includes the light guide element and a ht emitting diode (LED). The LED is used to emit light into the cone-shape hollow portion through the bottom portion.

Abstract: A backlight module including a light guide plate, a plurality of point light sources and a frame is provided. The light guide plate includes a body, a positioning structure and a plurality of first micro-structures. The body has at least one light incident surface, an upper surface connected with the light incident surface, and at least one side surface connected with the light incident surface and the upper surface. The positioning structure is located on the side surface, wherein the upper surface has a first eliminating region adjacent to and surrounding the positioning structure. The first micro-structures are arranged on the upper surface except the first eliminating region. The point light sources face the light incident surface. The light guide plate is positioned in the frame by matching the positioning structure with a positioning component of the frame. A display device including the backlight module aforementioned is also provided.

Abstract: Light that enters from an incident light surface of a light guide plate includes not only light which is guided toward the forward direction in front but also light whose optical path is modified by optical elements while progressing through the inside of the light guide plate, and thus wasteful emission from an emitting surface is inhibited. Lights are guided in a longitudinal direction of the optical elements. Light is diffused in the course over which the lights are guided and the region to which they are guided. The lights are guided by the optical elements in the longitudinal direction of the optical elements, and thereby light diffusivity is exhibited in the region in which the optical elements are provided while controlling the directivity of the light.

Abstract: A display device includes a display panel, a display area, a non-display area, a substrate member attached to the display panel with an adhesive layer interposed therebetween and including a touch panel and an operation section formed in the non-display area and used for performing an input operation on the touch panel, a step portion formed at least by a side portion of the display panel and a side portion of the adhesive layer such that a void is generated in a part between the display panel and the substrate member, and a light source unit disposed in the void such that at least a part of the light source unit is superimposed on the display panel in the step portion and configured to supply illumination light to the operation section to light the operation section.

Abstract: A tiled display is disclosed herein. The tiled display includes: a plurality of unit display units, wherein each of the unit display units includes: a panel assembly including a curved surface part of which both ends are curved surfaces; a light transmitting member disposed in a transparent plate shape and covering the curved surface part of the panel assembly; and a light guide member including a recess part recessed at one side thereof where the light guide member is combined with the light transmitting member, positioned adjacent to the curved surface part of the panel assembly, and positioned toward a direction in which an image is displayed from the panel assembly.

Abstract: The present disclosure provides a fixture for assembling a light strip and a back plate in an edge-type backlight module. The back plate includes a bottom plate and a lateral side, the light strip includes a base plate and an LED lamp, and the base plate of the light strip is connected to the lateral side of the back plate. The fixture includes a stopper, which includes a stopping slot for allowing the lateral side of the back plate and the light strip to pass therethrough. A bottom of the stopper is of a planar structure and is in close contact with a surface of the base plate away from the bottom plate of the back plate.

Abstract: A display apparatus includes a display unit which displays an image, a backlight unit which provides the display unit with a light, a receiving container which accommodates the backlight unit, and a supporting frame which is coupled to the receiving container and supports the display unit. The backlight unit includes a light incident area from which the light is emitted. The receiving container includes a guide bar which is adjacent to the light incident area of the backlight unit and coupled to the supporting frame.

Abstract: A light guide apparatus that can redirect light impinging on the apparatus over a wide range of incident angles and can concentrate light without using a tracking system and methods for fabrication.

Abstract: An optical fiber containing an alkali metal and capable of reducing Rayleigh scattering loss is provided. An optical fiber has a core and a cladding made of silica glass and enclosing the core. The cladding contains fluorine and has a refractive index lower than the refractive index of the core. The core contains first group dopants selected from the group of Na element, K element, or a compound thereof at an average concentration of 0.2 ppm or more and 10 ppm or less. The core also contains second group dopants for reducing the viscosity of silica glass and having a diffusion coefficient of 1×10?12 cm2/s or more and smaller than the diffusion coefficient of the first group dopants, by an average concentration of 0.2 ppm or more at a temperature of 2000° C. to 2300° C.

Abstract: Provided are: a prepolymer which is capable of forming a non-linear optical material that has excellent non-linear optical effect, heat resistance, withstand voltage and transparency; a curable material which contains the prepolymer; a coating composition which contains the curable material and a solvent; a non-linear optical material which is obtained by curing the curable material; an optical waveguide which uses the non-linear optical material; and a light control device which is provided with the optical waveguide. The present invention uses a prepolymer having a crosslinkable functional group, which is obtained by reacting one or more compounds (X) that are selected from the group consisting of compounds (X1), compounds (X2) and compounds (X3), a compound (Y) that is represented by formula (Y), a compound (Z) that has three or more phenolic hydroxyl groups, and an organic compound (B) that exerts a non-linear optical effect and has a reactive group.

Abstract: An embodiment of the present invention relates to an MMF with a structure for reducing length dependence of optical characteristics while maintaining bend-insensitivity. The MMF has a trench portion provided between a core portion and a cladding portion and having a refractive index lower than that of the cladding portion. In a cross section of the MMF, the trench portion in at least a partial section of the MMF has a non-circularly symmetric shape with respect to an intersection between the optical axis and the cross section.

Abstract: The invention relates to an optical fiber comprising a core and a cladding, wherein the core is made of a glass composition having a near-zero electrostrictive coefficient M11, to reduce the effect of stimulated Brillouin Scattering (SBS). The invention further relates to a compensation fiber segment for connection to a silica optical fiber, the compensation fiber segment being made of a glass composition having an electrostrictive coefficient that opposes that of the silica optical fiber so that an acoustic wave transmitted to compensation fiber segment from the silica optical fiber will generate an acoustic wave within the compensation fiber segment that is about 180 degrees out of phase with the that acoustic wave transmitted from the silica optical fiber, thereby minimizing the effect of stimulated Brillouin Scattering.

Abstract: A method of making a grating in a waveguide includes forming a waveguide material over a substrate, the waveguide material having a thickness less than or equal to about 100 nanometers (nm). The method further includes forming a photoresist over the waveguide material and patterning the photoresist. The method further includes forming a first set of openings in the waveguide material through the patterned substrate and filling the first set of openings with a metal material.

Abstract: Technologies are generally described to form a waveguide in a polymer multilayer comprising a first and second polymer layer. The waveguide may be formed by directing light beams toward the polymer multilayer to form first and second cladding regions in the polymer multilayer, where the first and second cladding regions comprise a mixture of the first and second polymer layers. The first and second cladding regions may define a third cladding region and a waveguide core therebetween, where the third cladding region comprises a portion of the second polymer layer, and the waveguide core comprises a portion of the first polymer layer. In some examples, the polymer multilayer may be formed on a substrate such that the waveguide is formed on the substrate.

Abstract: A standard-CMOS-process-compatible optical mode converter transitions an optical mode size using a series of adjacent regions having different optical mode sizes. In particular, in a partial-slab-mode region, which is adjacent to an initial rib-optical-waveguide-mode region, a width of a slab portion of the rib-type optical waveguide decreases and a width of a rib portion of the rib-type optical waveguide decreases to a first minimum tip size. Then, in a slab-mode region, which is adjacent to the partial-slab-mode region, the width of the slab portion decreases to a second minimum tip size. In addition, a dielectric layer is disposed over the slab portion, the rib portion and the BOX layer in the partial-slab-mode region, the slab portion and the BOX layer in the slab-mode region, and the BOX layer in a released-mode region that is adjacent to the slab-mode region and that does not include the semiconductor layer.

Abstract: The present disclosure discloses an optical fiber welding machine, including a device for butt joint of the optical fiber's core. The said device comprises a base and a number of units with V-shape groove. The base and the units are shaped respectively. The said units are mounted on the base fixedly. Comparing with the traditional overall molding device for butt joint of the optical fiber's core, the disclosed embodiment splits said traditional device, which has complicated structure and high accuracy requirements, into a base and a number of V-shape groove units, thus simplifies the shape of the components, which are shaped respectively, so as to facilitate the purpose of molding mould and shaping components, and then the v-shape groove units are mounted on the base. After completion of assembly, a v-shaped slot is grooved on top of each v-shape groove unit to ensure enough precision. The disclosed embodiment reduces both the mold manufacturing cost and the molding cost of components.

Abstract: Methods and systems for grating couplers incorporating perturbed waveguides are disclosed and may include in a semiconductor photonics die, communicating optical signals into and/or out of the die utilizing a grating coupler on the die, where the grating coupler comprises perturbed waveguides. The perturbed waveguides may include rows of continuous waveguides with non-discrete scatterers extending throughout a length of said perturbed waveguides a variable width along their length. The grating coupler may comprise a single polarization grating coupler comprising perturbed waveguides and a non-perturbed grating. The grating coupler may comprise a polarization splitting grating coupler (PSGC) that includes two sets of perturbed waveguides at a non-zero angle, or a plurality of non-linear rows of discrete shapes. The PSGC may comprise discrete scatterers at an intersection of the sets of perturbed waveguides. The grating coupler may comprise individual scatterers between the perturbed waveguides.

Abstract: Embodiments of present invention provide a digital dispersion compensation module. The digital dispersion compensation module includes a multi-port optical circulator; and a plurality of dispersion compensation units connected to the multi-port optical circulator, wherein at least one of the plurality of dispersion compensation units includes a fiber-bragg grating (FBG) having a first port and a second port; and an optical switch being capable of selectively connecting to one of the first port and the second port of the FBG, wherein the at least one of the plurality of dispersion compensation units is adapted to provide a positive dispersion to an optical signal, from the multi-port optical circulator, when the optical switch connects to the first port of the FBG and is adapted to provide a negative dispersion to the optical signal when the optical switch connects to the second port of the FBG.