Abstract: The invention concerns a security element in the form of a multi-layer film body having a volume hologram layer with two different items of optical information and a process for the production of such a security element.

Abstract: An exterior part (200) includes (a) a structure color generation portion (210) having a minute shape (structure color generation region (211)) formed therein, light in a visible light range being produced from the minute shape by a physical phenomenon such as interference or diffraction with the incidence of light, and (b) a resin portion (220) that is made of resin having a light transmitting property and serves as the outer surface of a product, (c) the structure color generation portion (210) and the resin portion (220) are formed by molding, and (d) the structure color generation portion (210) is made of resin different from the resin of the resin portion (220), and covered with the resin portion (220).

Abstract: A composition for producing optical elements having a gradient structure, particularly for holographic applications, is formed by a refractive index gradient. The composition is produced from one or more polymerizable and/or polycondensable monomers and at least one biological polymer. A potential difference is generated for the directed diffusion of the monomers by inducing a local polymerization or polycondensation. The result is the formation of a refractive index gradient.

Abstract: A method for replicating production of a 3D parallax barrier is capable of transfer-printing a 3D parallax barrier pattern on a planar transparent substrate mainly with a glass photo mask having the 3D parallax barrier pattern through processes of photo resistor coating, exposure, and development by using a photolithography technology, thereby achieving the purpose of replicating production.

Abstract: The present invention discloses an alignment substrate that includes a base substrate and an alignment layer arranged on the base substrate. A plurality of unit pixels is defined in the base substrate. The alignment layer includes at least two sub-alignment portions dividing the unit pixel into at least two domains. Each sub-alignment portion is arranged in a different domain of the at least two domains and is aligned to have a different pretilt direction from the other sub-alignment portions.

Abstract: A phase-type diffraction device includes a substrate having a front surface and a solidified liquid crystal layer formed on the front surface of the substrate and constituted by a continuous film containing at least a liquid crystal compound. The solidified liquid crystal layer is constituted by first, second and third regions arranged periodically, the third region being interposed between the first region and the second region. The first region is optically anisotropic and the second region is optically isotropic, the third region is not optically isotropic, a degree of orientation of mesogens of the liquid crystal compound being lower than that of the first region. An in-plane average refractive index ni of the second region is different from an in-plane average refractive index na of the first region and an in-plane average refractive index nm of the third region is between ni and na.

Abstract: A polymer waveguide for coupling with one or more light transmissible devices, a method of fabricating a polymer waveguide for coupling with one or more light transmissible devices, and a method of coupling a polymer waveguide with one or more light transmissible devices. The polymeric waveguide comprises a grating structure.

Abstract: A fabrication method is provided which makes it possible to obtain a microlens that is more tightly spaced (the space between individual microlenses is smaller) than in the related art, even when the same fabrication process as that in the related art is used. The present invention provides a mask used for fabrication of a microlens to irradiate a photosensitive microlens material on a substrate with a patterned light beam, including a main layout, and a sub-layout provided around the main layout, in which when the mask is irradiated with a light beam, a first beam pattern is obtained by the main layout at a position corresponding to a center portion of the microlens, and a second beam pattern separated (resolved) from the first beam pattern is obtained by the sub-layout around the first beam pattern.

Abstract: The present disclosure relates to a method for manufacturing the patterned retarder used in the three-dimensional display device. The present disclosure suggests a method for manufacturing a patterned retarder comprising: defining a first retarder region and a second retarder region in the patterned retarder; forming a first polarization pattern at the first retarder region by a partial exposure process having a first exposure energy; and forming a second polarization pattern at the second retarder region by whole exposure process having a second exposure energy. By manufacturing the patterned retarder with lower exposure energy, it is possible to reduce the whole manufacturing takt time, so that the production yield can be enhanced and the production cost can be reduced.

Abstract: The present invention discloses a UV glass production method, comprising the steps: arranging a blade on an exposure stage; controlling the position of an exposure area on a glass substrate by regulating the position of the blade; removing a film layer from the area to be transparent; and forming a UV mask in the area to be shaded. In the present invention, a mask blade is adopted, can individually move and be accurately controlled individually; thus, rays of an exposure machine can be accurately positioned for producing a UV glass which meets standards. Moreover, in the present invention, there is no need to design a light cover especially so as to save the design and production cost of the light cover; thus, the present invention can ensure the production accuracy and effectively save the production cost.

Abstract: An optical wavelength dispersion device includes a first substrate, an input unit formed on the first substrate having a slit for receiving an optical signal, a grating formed on the first substrate for producing a diffracted light beams from the optical signal, a first optical reflector formed on the first substrate for reflecting the diffracted light beams from the grating for outputting, and a second substrate covered on the top of the input unit and the grating, wherein the input unit, the grating and the first optical reflector are formed from a photo-resist layer by high energy light source exposure.

Abstract: A recessed portion forming method for forming a plurality of recessed portions in a thermally deformable heat mode recording material layer is provided, which method includes: a recessed portion forming step of applying condensed light emitted from an optical system including a light source, to the recording material layer to form the recessed portions; an inspection light illumination step of applying inspection light to the recessed portions during or after formation of the recessed portions in the recording material layer; a detection step of detecting a light quantity of the inspection light reflected or diffracted from the recessed portions; and an output regulation step of regulating an output of the light source based upon the light quantity so that the light quantity becomes a predetermined value. Methods for manufacturing a pit-projection product, a light emitting element, and an optical element, using this method are also provided.

Abstract: There is provided a method of fabricating a lithography mask, the method including: forming a transparent polymer layer on a surface of a first substrate where a convex-concave pattern is formed; separating the transparent polymer layer from the first substrate, the transparent polymer layer having a convex-concave surface formed by the convex-concave pattern of the first substrate transferred thereonto; depositing a metal thin film on the convex-concave surface; forming a viscous film on a second substrate; disposing the transparent polymer layer on the second substrate such that the viscous film and metal thin film are partially bonded together; and separating the transparent polymer layer from the second substrate such that a portion of the metal thin film bonded to the viscous film is removed, wherein a metal thin film pattern having the portion of the metal thin film removed therefrom is formed on the convex-concave surface.

Abstract: A spacer wafer for a wafer-level camera, a wafer-level camera including the spacer wafer and a method of manufacturing a spacer wafer include a layer of photoresist being formed over a substrate, the layer of photoresist being exposed to radiation through a mask that defines a spacer geometry for at least one wafer-level camera element. The layer photoresist is developed, such that the layer of photoresist is the spacer wafer for the wafer-level camera.

Abstract: An optical wavelength dispersion device includes a first substrate, an input unit formed on the first substrate having a slit for receiving an optical signal, a grating formed on the first substrate for producing a first light beam form the optical signal for outputting, and a second substrate covered on the top of the input unit and the grating, wherein the input unit and the grating are formed from a photo-resist layer by high energy light source exposure.

Abstract: In a fabricating method of a touch screen panel, a conductive layer and an insulating layer are sequentially formed on a same surface of a transparent substrate. The conductive layer and the insulating layer are co-patterned using a halftone mask to form first connection patterns having separated patterns and the insulating layer being patterned on the first connection patterns to expose regions of the first connection patterns. A transparent electrode layer is formed on the transparent substrate having the first connection patterns and the insulating layer. The transparent electrode layer is patterned to form first sensing patterns connected to the first connection patterns through the exposed regions of the first connection patterns and connected along a first direction, and to form second sensing patterns disposed between the first sensing patterns, wherein the second sensing patterns are insulated from the first sensing patterns and connected along a second direction.

Abstract: A method for interlaminating a transparent embossed hologram, the transparent embossed hologram comprising a support having two sides, at least one of the two sides either itself being embossed or having a layer thereon which is embossed and a layer of a HRI-material contiguous with the embossed side or embossed layer, comprising the steps of: a) conditioning the outermost surface of the layer of inorganic HRI-material with at least one organic liquid; b) drying the outermost surface of the layer of the inorganic HRI-material thereby providing a conditioned outermost surface of the layer of inorganic HRI-material; c) applying an adhesive layer to the conditioned outermost surface; and d) laminating the outermost surface of inorganic HRI-material to an optionally transparent film, wherein the at least one organic liquid is selected from the group consisting of ketones, ethers, heterocyclic ethers, lactams, amides, halo-aliphatic compounds, nitriles and esters; wherein at least one of the support and the film i

Abstract: A lens substrate includes a base substrate, a first lens electrode and a first signal line. The base substrate includes a lens area and a peripheral area surrounding the lens area. The first signal line in the peripheral area and includes a layered structure in which a first transparent conductive layer and a metal layer directly contact each other. The first lens electrode is in the lens area and includes the first transparent conductive layer excluding the metal layer. The first signal line is in the peripheral area. The first signal line is connected to the first lens electrode and includes a layered structure in which the first transparent conductive layer and the metal layer directly contact each other.

Abstract: An optical touch sensing structure includes a transparent substrate and a stacked transparent optical layer. The transparent substrate has an upper surface. The stacked transparent optical layer is disposed on the upper surface of the transparent substrate with a portion of the upper surface being exposed. The stacked transparent optical layer is formed by stacking at least one first transparent optical layer and at least one second transparent optical layer. The refractive index of the first transparent optical layer is greater than the refractive index of the second transparent optical layer. The stacked transparent optical layer is adapted to allow a visible light to pass through and has a rough surface. When an infrared light is incident to the stacked transparent optical layer, the infrared light is reflected by the stacked transparent optical layer and scattered by the rough surface.

Abstract: A mask includes: a substrate that includes a central area and a peripheral area disposed around the central area; and lenses disposed in rows and columns, in the central area and the peripheral area. The lenses of opposing sides of the peripheral area may be disposed in different rows or columns. For a given amount of input light, the lenses of the peripheral area may focus less light on a substrate than the lenses of the central area. The mask may be disposed over the substrate in different positions, and then the substrate may be irradiated through the mask, while the mask is in each of the positions. The peripheral portion of the mask may be disposed over the same area of the substrate, while the mask is in different ones of the positions.

Abstract: The present invention has an object to provide a photosensitive resin composition for optical waveguide formation, which has low transmission loss and can form a waveguide pattern with high shape accuracy at low cost; an optical waveguide; and a method for producing an optical waveguide. The present invention provides a photosensitive resin composition for optical waveguide formation comprising at least: a polymer containing at least a (meth)acrylate structure unit having an epoxy structure, and a (meth)acrylate structure unit having a lactone structure and/or a vinyl monomer structure unit having an aromatic structure; and a photoacid generator, of which one or both of a core layer and a cladding layer are formed of a cured product.

Abstract: A production method of an optical waveguide for a connector is provided, which reduces an optical coupling loss. Cores are formed in a crossing pattern, a branched pattern or a linear pattern, and then an over-cladding layer formation photosensitive resin layer is formed over the cores. In turn, a heat treatment is performed at a temperature of 70° C. to 130° C. to properly form mixed layers in interfaces between the cores and the photosensitive resin layer. By thus forming the mixed layers, the connector optical waveguide can be produced as having a reduced optical coupling loss.

Abstract: A large mask with random apertures may be formed by forming a smaller mask (also called a cell mask) with a random pattern of transmissive apertures which is then repeatedly replicated to create the large mask. The random pattern may be created by perturbing the aperture locations by a small amount or the apertures may be randomly placed within the cell mask provided certain criteria are met. Alternatively, a large mask with a random pattern of transmissive apertures may be formed without using a cell mask. This large mask may be used to fabricate diffusers and other devices that do not suffer from the interference, diffraction and other optical effects common in devices having structures that are non-randomly patterned.

Abstract: A method of fabricating a transflective type liquid crystal display device includes: forming gate and data lines with a gate insulating layer therebetween on a substrate and crossing each other to define a pixel region that includes a switching region, a reflective region, and a transmissive region; forming a thin film transistor corresponding to the switching region and connected to the gate and data lines; forming a first passivation layer on the thin film transistor; forming a reflective plate on the first passivation layer in the reflective region; forming a second passivation layer on the reflective plate; forming a pixel electrode on the second passivation layer and connected to a drain electrode of the thin film transistor; forming a third passivation layer on the pixel electrode.

Abstract: Photopolymer resins are disclosed which includes metal and/or ceramic surface chelating agents to provide strong bonding of the photopolymer resin to the inorganic surface of the first information layer of an optical disc. The resins also include a fast surface cure and glass transition temperature controlling monomers that provides easy stamper separation The disclosed photopolymer resins also include short wavelength (<405 nm) surface cure initiators. The resins may also optionally include shrinkage control oligomers and/or polymer fillers or a combination of both Use of the disclosed resins eliminates two steps from the manufacture of a multiple information layer optical disc as the formation of spacer layers and the curing of spacer layers is no longer necessary.

Abstract: An optical arrangement has a laser configured to emit a laser beam, an amplitude mask and a focusing element. The amplitude mask is disposed between the laser and the focusing element in a path of the laser beam such that the laser beam hits the amplitude mask before being modified by the focusing element so as to direct the laser beam to a focal point within a photosensitive material.

Abstract: Optical elements, in particular for holographic applications, have a gradient structure formed by a refractive index gradient and include one or more organic polymers and at least one ionic liquid.

Abstract: A method of making optical devices includes applying an energy sensitive protective material and an energy sensitive advanced optical material to a surface. The surface can be on the optical device or on a carrier, such as a thin sheet, to be applied to the optical device. Light energy is applied through a special production filter to cure the energy sensitive protective material on the surface while blocking light energy outside a selected wavelength spectrum from reaching the material. A portion of the optical device can then be masked, and light energy outside the spectrum filtered by the special production filter can be applied to activate the unmasked portion of the advanced optical material. The special production filter allows curing of the protective material using light energy in a limited (e.g., visible) spectrum so that the advanced optical material can be activated using light energy in the ultraviolet spectrum.

Abstract: An electro-optical printed circuit board contains electrical conductor tracks on the one hand and optical waveguide structures on the other hand. The optical waveguide structures comprise a bottom layer, a core layer and a cladding layer. Visible areas are applied to the printed circuit board, and the core layer is applied later both to the bottom layer as well as the visible areas and structured both on the bottom layer as well as the visible areas. This structure is then transferred to the visible areas, e.g. by etching. Reference marks are thus produced which contain the information on the actual position of the optical waveguide structures.

Abstract: A method for producing an optical part includes an irradiation process for irradiating a radiation-sensitive polymerizable composition with a radiation. The radiation-sensitive polymerizable composition includes at least a polymerizable compound (a) and a polymerizable or non-polymerizable component (c). The irradiation process includes at least a first step of irradiating with a radiation only a first irradiation region that is a portion of the radiation-sensitive polymerizable composition and a second step of irradiating with a radiation only a second irradiation region that is a portion of the radiation-sensitive polymerizable composition and is different from the first irradiation region in at least one of size and position. When the component (c) is polymerizable, the polymerization rate of the component (c) is controlled to be lower than that of the polymerizable compound (a) in the first and the second steps.

Abstract: A micro-lens array and a method for fabricating a micro-lens includes forming a first lens formation material layer on and/or over a micro-lens formation area of a semiconductor substrate, and then forming a portion of the lens formation material layer as a first micro-lens using a first mask. A second lens formation material layer is formed adjacent to the first micro-lens on and/or over the micro-lens formation area. The second lens formation material layer is also formed as a second micro-lens using a second mask which is a different type from that of the first mask.

Abstract: A method of: directing an exposing light through an optical diffuser; directing the diffused light though a photomask having transparent areas corresponding to a gray-tone pattern; directing the masked light onto a photoresist material on a substrate; developing the photoresist to produce a three dimensional structure in the photoresist.

Abstract: An optical assembly includes a solid spacing layer between a plenoptic microlens array (MLA) and a pixel-level MLA, avoiding the need for an air gap. Such an assembly, and systems and methods for manufacturing same, can yield improved reliability and efficiency of production, and can avoid many of the problems associated with prior art approaches. In at least one embodiment, the plenoptic MLA, the spacing layer, and the pixel-level MLA are created from optically transmissive polymer(s) deposited on the photosensor array and shaped using photolithographic techniques. Such an approach improves precision in placement and dimensions, and avoids other problems associated with conventional polymer-on-glass architectures. Further variations and techniques are described.

Abstract: A color filter including a first photo-spacer, and a second photo-spacer having a smaller film thickness than that of the first photo-spacer, wherein the second photo-spacer has a cross-sectional configuration whose longitudinal width is made greater than the lateral width. These photo-spacers are formed by making use of a photomask which includes a first aperture pattern for forming the first photo-spacer, a second aperture pattern for forming the second photo-spacer which has a smaller film thickness than that of the first photo-spacer, wherein an aperture of the second aperture pattern has a lateral width in the range 2.0-10.0 ?m and the ratio of lateral width to longitudinal width is confined to 11.25 or more.

Abstract: An organic-inorganic hybrid electroluminescent device having a semiconductor nanocrystal pattern prepared by producing a semiconductor nanocrystal film using semiconductor nanocrystals, where the nanocrystal is surface-coordinated with a compound containing a photosensitive functional group, exposing the film through a mask and developing the exposed film

Abstract: A light guide plate for a backlight. The light guide plate includes: a light source unit for generating light; a light guide plate proximate to the light source unit and including an upper surface and a lower surface; and a light emission pattern configured to diffuse a portion of the light directed toward an image display panel, and a first straight pattern configured to channel the light along a direction substantially parallel to a direction of propagation of the light generated by the light source unit, both the light emission pattern and the first straight pattern being disposed on one of the upper surface and the lower surface of the light guide plate, in which the first straight pattern has peaks and valleys formed in alternating and repeating manner in a direction substantially perpendicular to a direction of propagation of the light generated by the light source unit.

Abstract: An asymmetric slotted waveguide and method for fabricating the same. The slotted waveguide is constructed in silicon-on-insulator using a Complementary metal-oxide-semiconductor (CMOS) process. One or more wafers can be coated with a photo resist material using a photolithographic process in order to thereby bake the wafers via a post apply bake (PAB) process. An anti-reflective coating (TARC) can be further applied on the wafers and the wafers can be exposed on a scanner for the illumination conditions. After a post exposure bake (PEB), the wafers can be developed in a developer using a puddle develop process. Finally, the printed wafers can be processed using a shrink process to reduce the critical dimension (CD) of the slot and thereby achieve an enhanced asymmetric slotted waveguide that is capable of guiding the optical radiation in a wide range of optical modulation applications using an electro-optic polymer cladding.

Abstract: A lens panel includes a first substrate, a second substrate, and a liquid crystal layer. The first substrate includes a first base substrate, a first electrode disposed on the first base substrate, and a first alignment layer disposed on the first electrode. The first alignment layer includes a unit lens area. The unit lens area includes a first alignment area having a first azimuthal angle and a second alignment area having a second azimuthal angle.

Abstract: A beam splitter optical surface comprises a transparent substrate and a multilayer optical coating applied in a pattern onto the transparent substrate. The multilayer optical coating has at least an optically reflective layer and an optically absorbent layer.

Abstract: A via hole is formed in a first cladding layer laminated on a wiring board. A conductive material is filled in the via hole so as to form a first conductor portion (a portion of a conductive via) having a mushroom-like shape projecting from a surface of the first cladding layer. Then, a second cladding layer is formed to cover the first conductor portion, the first cladding layer and a core layer, and a via hole is formed in the second cladding layer. A conductive material is filled in the via hole so as to form a second conductor portion (a remaining portion of the conductive via) connected to the first conductor portion.

Abstract: A solid-state imaging device producing method includes the steps of: applying a resist material onto a substrate in which a channel region is formed; forming a resist layer by exposure and development of the resist material using a mask, the resist layer having an opening and a thin-film portion, the mask having a first region through which light is transmitted and a second region through which a smaller quantity of light than that the light transmitted through the first region is transmitted; subjecting the substrate to ion implantation using the resist layer as a mask to form an impurity region; etching the substrate using the resist layer as a mask after the ion implantation to form an alignment mark; and forming an electrode on the impurity region and part of the channel region using the alignment mark as a reference.

Abstract: A silicone composition comprises (A) an organopolysiloxane resin having the formula (R1R22SiO1/2)v(R22—SiO2/2)w(R2SiO3/2)x(R3SiO3/2)y(SiO4/2)z, wherein R1 is C1 to C10 hydrocarbyl, R2 is R1 or an epoxy-substituted organic group, R3 is C4 to C8 alkyl, v is from 0 to 0.3, w is from 0 to 0.5, x is from 0 to 0.9, y is from 0.1 to 0.8, z is from 0 to 0.5, and v+w+x+y+z=1, provided that the organopolysiloxane resin has an average of at least two silicon-bonded epoxy-substituted organic groups per molecule; (B) an organic solvent; and (C) a photoinitiator. Planar optical waveguide assemblies having one or more layers comprising the silicone composition, and methods for preparing the planar optical waveguide assemblies are provided.

Abstract: Embodiments of the invention relate to methods useful in the fabrication of nanostructured devices for optics, energy generation, displays, consumer electronics, life sciences and medicine, construction and decoration. Instead of nanostructuring using colloids of particles, special vacuum deposition methods, laser interference systems (holography), and other low-throughput limited surface area techniques, we suggest to use nanotemplate created by novel nanolithography method, “Rolling mask” lithography. This method allows fast and inexpensive fabrication of nanostructures on large areas of substrate materials in conveyor-type continuous process. Such nanotemplate is then used for selective deposition of functional materials. One of embodiments explains deposition of functional materials in the exposed and developed areas of the substrate. Another embodiment uses selective deposition of the functional material on top of such template.

Abstract: A method for creating or forming a functionally graded 3D ordered open-cellular microstructure, and a functionally graded 3D ordered open-cellular microstructure. In one embodiment, the functionally-graded three-dimensional ordered open-cellular microstructure includes a first three-dimensional interconnected pattern of polymer waveguides having a first three-dimensional pattern; a second three-dimensional interconnected pattern of polymer waveguides having a second three-dimensional pattern differing from the first three-dimensional pattern; and an interface connected with the first three-dimensional interconnected pattern of polymer waveguides and the second three-dimensional interconnected pattern of polymer waveguides. Here, the term “functionally graded” refers to a spatial variation in the physical microstructure—and thus the properties—through the thickness of the material.

Abstract: A manufacturing device of optical deflectors and a manufacturing method of the same are revealed. The manufacturing device includes a movable work platform, a substrate, a lens and a femtosecond laser source. The substrate is disposed on the movable work platform and is coated with a photoresist polymer film. The lens is arranged at one side of the movable work platform. The femtosecond laser source produces a femtosecond laser that passes through the lens and projects onto the photoresist polymer film at a non-focal position of the lens so as to produce an optical deflector. The optical deflector is produced only by the femtosecond laser projected onto the photoresist polymer film at the non-focal position. Thus the production efficiency of the optical deflector is improved.

Abstract: The invention relates to a method of generating a laser marking in a security document by means of at least one laser beam, the security document having at least one laser-markable layer and also at least one reflecting layer which overlaps at least partly with the at least one laser-markable layer and has opaque regions. The at least one reflecting layer has at least one transparent region and, at least visually, is not significantly altered by the laser treatment of the laser-markable layer.

Abstract: A method for producing surface convexes or concaves disposes a mask member having light transmitting sections and non-light transmitting sections over and spaced from one side of a photosensitive film including a photosensitive resin composition, and a light diffusing member is disposed on the opposite side of the photosensitive film across the mask member. Light is irradiated from a light source disposed on the opposite side of the mask member across the light diffusing member to subject the photosensitive film to light exposure through the light diffusing member and the light transmitting sections of the mask member. Exposed portions or unexposed portions of the photosensitive film are removed by development to produce convexes or concaves on the photosensitive film in shapes determined by shapes of the exposed portions or unexposed portions. In exposure, conditions such as haze of the light diffusing member are controlled to control the shapes of the exposed portions or unexposed portions.

Abstract: The present invention provides a photo-curable transfer sheet by which an optical information recording medium (e.g., DVD) having small thickness and high capacity can be advantageously prepared, and which is improved in transferring property of pits and the like and curing property. The photo-curable transfer sheet has a photo-curable transfer layer comprising a photo-curable composition deformable by application of pressure, wherein the photo-curable composition comprises a polymer having a glass transition temperature of not less than 80° C. and a reactive diluent having a photopolymerizable functional group. The invention also provides a process for the preparation of an optical information recording medium using the sheet, and the optical information recording medium.

Abstract: A method of optical fabrication comprises coating a substrate with a photocuring material, controlling the application of light to the photocuring material so as to control the intensity and pattern of the light both in-plane and out of plane, and developing the photocuring material.

Abstract: Embodiments of the present invention describe a waveguide-based photodetector device and its methods of fabrication. The waveguide photodetector device comprises a substrate having a cladding structure formed thereon. A waveguide element for receiving optical signals is disposed within the cladding structure. A portion of the waveguide element is encapsulated by a photodetector element that detects the optical signal received by the waveguide element and generates an electrical signal based on the optical signal. Encapsulating the waveguide element in the photodetector element improves coupling efficiency and enables a waveguide photodetector device with higher speeds and higher responsivity.