Abstract: An optical coupling device enabling spherical or hemispherical light sources to be more fully utilized by gathering more of the emitted radiation and reducing the angle of emission. The optical coupling device includes a first conic reflector having an aperture at the first conic reflector vertex; a second conic reflector coaxial with the first conic reflector and opening toward the first conic reflector; a light source positioned at the second conic reflector vertex; and a negative element located at the aperture for reducing the numerical aperture of the light emitted from the optical coupling device. The optical coupling device may include a refractive medium between the first and second conic reflectors. The present invention provides for improved efficiencies when transferring or coupling optical energy into additional optical systems, and may be used with solid state light as well as conventional sources.

Abstract: In an embodiment, light from a single mode light source may be deflected into a low index contrast (LIC) waveguide in an opto-electronic integrated circuit (OEIC) (or “opto-electronic chip”) by a 45 degree mirror. The mirror may be formed by polishing an edge of the die at a 45 degree angle and coating the polished edge with a metal layer. Light coupled into the LIC waveguide may then be transferred from the LIC waveguide to a high index contrast (HIC) waveguide by evanescent coupling.

Abstract: A luminometer is provided comprising a waveguide sample holder and one or more detectors. The waveguide sample holder may include a hollow region to hold the sample. The waveguide sample holder can be made of material that guides emission light to a bottom end of the waveguide sample holder. One or more detectors may be provided which detect the emission light coming out of the bottom of the waveguide sample holder. A fluorometer/photometer is also provided that comprises a waveguide sample holder, one or more excitation light sources, and one or more optical detectors. The waveguide sample holder has a hollow region to hold the sample. The excitation light is introduced at an angle or perpendicular to one surface of the waveguide sample holder. The waveguide sample holder is made of material that can guide emission light to the bottom end of the waveguide sample holder. There are one or more detectors that detect the emission light coming out of the bottom of the waveguide sample holder.

Abstract: To provide an optical connector which enables heat generated by an optical interface module arranged on the lower surface of the optical connector to be efficiently dissipated from the upper surface of the optical connector. The optical connector includes an optical transmission path 101 including a 45-degree mirror 106 at an end section thereof, wherein, in the optical transmission path 101, the lower surface on which an optical input/output section 102 is provided, and the upper surface facing the lower surface are sandwiched by metal patterns 107 and 108 having a heat conductivity higher than that of the optical transmission path 101, and wherein the metal patterns 107 and 108 are physically connected to each other by heat dissipation vias 103 having a heat conductivity higher than that of the optical transmission path 101.

Abstract: A beam coupler assembly for a fiber laser is disclosed. The assembly includes a housing having a sidewall with an interior surface, an exterior surface, a first end and a second end. A first seal extending from the interior surface of the tubular housing and dividing the housing into a first section and a second section is also provided. The first section and second section are environmentally isolated from one another. However, the first seal is substantially optically neutral. An input collimator unit received within the first end of the sidewall of the housing and into the first section and is releasably coupled thereto. An output collimator unit received within the second end of the sidewall of the housing and into the second section and is also releasably coupled thereto.

Abstract: A signal detector system (10) comprises a single signal detector (11) having a limited on-time during which any received electromagnetic signal can be assessed. The signal detector (11) receives electromagnetic signals from a single direction in space (D) through a single optical fibre (12), a signal splitter 13 which splits the collected signal between three optical paths (20, 30 and 40), and a signal combiner (14) which combines the portions of the signal transmitted by the three optical paths (20, 30 and 40) and transmits the combined signal to a signal detector input (15). Each of the optical paths (20, 30 and 40) includes a respective optical delay (21, 31 and 41) designed to delay transmission of any received signal towards the signal detector (11). In this manner the signal detector (11) will receive any signals that arrived at the optical fibre (12) during three separate periods of time.

Abstract: An optical waveguide device and an optical communication module are provided. In the optical waveguide device which includes a core and a cladding layer formed around the core and has one end formed to be inclined so as to refract input and output signals, the core includes therein a diffraction portion for diffracting an optical signal incident through the cladding layer to propagate straight through the core. Thus, it is possible to prevent deterioration of an optical signal coupling ratio in implementing a technique of transmitting optical signals in opposite directions.

Abstract: An apparatus comprises an optical waveguide, a grating for coupling light into the waveguide, and an optical element for splitting a light beam into a plurality of beams that strike the grating at different angles of incidence.

Abstract: A photodetector device, comprises an optical input, a nanoscale silicon waveguide and an electrical output. The waveguide is a high-contrast waveguide, with a refractive index contrast with the outside environment of more that 10%. The optical mode distribution across the waveguide has a peak intensity in correspondence of surface states of the nanoscale silicon waveguide. A related method is also disclosed.

Abstract: In the sending and receiving of a signal through an optical waveguide, an unknown substrate connected to the optical waveguide can be recognized.

Abstract: An arrangement for a fiber optic microphone having at least one pair of optical fibers, each having an input end portion and an output end portion made of a material having a critical refractive angle ?crit and having a numerical aperture NA. The input end portion of a first fiber is connectable to a source of light and the output end portion of a second fiber is connectable to a photoelectrical transducer. Both end portions have an inner diameter, an axis and a rim. The input and output end portions are mutually affixed along a single plane with their rims touching each other at a point, the axes forming an angle ? therebetween. The rims are cut with respect to the axis, at an angle in a plane perpendicular to the single plane and to a bisector of angle ? at the point, where ?=2×?crit?NA.

Abstract: A photonic crystal is configured with wavelength converting material to act as a concentrator for electromagnetic energy. The concentrator may also be configured with energy conversion devices to convert the electromagnetic energy into another form of energy.

Abstract: Techniques for generating terahertz (THz) radiation are provided in which each nonlinear crystal in an array of such crystals is coupled to one or more corresponding waveguides such that any THz radiation generated in any single crystal is coupled into that crystal's THz waveguide structure. After the THz radiation is generated in the crystals and coupled into the waveguides, the individual THz signals may be coherently combined to form a single THz signal (non-coherent configurations are provided as well). Crystal-waveguide arrays embodying the techniques can be used to implement efficient, robust, and compact THz sources suitable for applications such as security screening, medical imaging, quality control and process monitoring in manufacturing operations, and package and container inspection.

Abstract: A suspension board with circuit includes a metal supporting board including a board trench portion, an insulating base layer formed on a surface of the metal supporting board, a conductive pattern formed on a surface of the insulating base layer, and an optical waveguide provided to overlap the board trench portion when projected in a thickness direction of the metal supporting board. At least a part of the optical waveguide is positioned closer to the conductive pattern than to a back surface of the metal supporting board.

Abstract: The invention relates to a support element (1), for mounting at least two wave-modifying elements, with support of services, arranged parallel to each other. According to the invention, support element for mounting at least two wave-modifying elements and corresponding production method maybe achieved, whereby the support surfaces each have at least one opening and the openings are connected to each other by means of at least one through drilling.

Abstract: In an optoelectronic integrated circuit device comprising a vertical arrangement of integrated circuit layers, an optical signal is coupled between a first integrated circuit layer thereof and a second integrated circuit layer thereof. The optical signal is projected through a superlensing element positioned between the first and second integrated circuit layers.

Abstract: An optical isolator includes a birefringent material and a Faraday rotator. The birefringent material receives a forward light propagating in a forward direction and a backward light propagating opposite to the forward direction. The birefringent material has an optical axis, wherein the forward light has a first polarization aligned perpendicular to the optical axis and is configured to pass the first birefringent material substantially along the forward direction. At least a portion of the backward light has a second polarization not perpendicular to the optical axis. The first birefringent material can displace the backward light to form a first displaced backward light. A Faraday rotator can rotate the forward light, and the backward light or the first displaced backward light by a same predetermined angle along the rotation direction.

Abstract: A semiconductor device has printed wiring board (11) where electric wiring (18) connected to LSI chip (17) and to planar optical element (21) is formed, and where optical waveguide (25) which transfers light inputted into planar optical element (21) and/or light outputted from planar optical element (21) is fixed. Planar optical element (21) is mounted in one end of small substrate (13), and another end of small substrate (13) is connected to printed wiring board (11) by solder bump (26). One end of small substrate (13) where planar optical element (21) is mounted is fixed to printed wiring board (11) by a fixing mechanism. Small substrate (13) has flexible section (15), which is easily deformable compared with other portions of printed wiring board (11) and small substrate (13), in at least a partial region between one end where planar optical element (21) is mounted and another end electrically connected to printed wiring board (11).

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

Abstract: Disclosed in a method and a device in which a wave number of light in the waveguide mode of a photonic crystal optical waveguide is matched with that of the incident light, or a intensity ratio of electric field to magnetic field of the light in the waveguide mode of the photonic crystal optical waveguide is matched with that of the incident light, and furthermore, in addition to the method above, the distribution of light intensity on the incident end surface in the waveguide mode of the photonic crystal optical waveguide is matched with that of the incident light. A photonic crystal optical waveguide and channel optical waveguide are joined together, and the structure of the channel optical waveguide is wedge shaped in the joint section.

Abstract: A light guide comprising a base body and a plurality of outcoupling elements that are disposed on an outcoupling side of the base body and are provided to couple radiation out of the base body, said outcoupling elements being applied on a film. A method of producing the light guide.

Abstract: An optical waveguide includes a cladding film and a core formed integrally with the cladding film. The core includes a light guide portion formed on one surface of the cladding film, a light input portion, and a light output portion, the light input portion and the light output portion being formed in through-holes formed in the cladding film. A mirror surface is respectively formed at a connecting portion between the light guide portion and the light input portion and a connecting portion between the light guide portion and the light output portion. In manufacturing the optical waveguide, the cladding film is brought into close contact with a surface of a mold, the surface having a recessed groove thereon, and a UV-curable resin is injected under pressure through one of the through-holes opened in the cladding film into the recessed groove.

Abstract: A backlight assembly for feeding illuminating light to a passive display panel is disclosed. The backlight assembly comprises a plurality of waveguides being formed and/or embedded in at least one substrate and arranged to feed illuminating light to each sub-pixel position of the passive display panel in a manner such that each pixel region is illuminated by at least two waveguides, wherein each waveguide of the at least two waveguides is disposed to illuminate one sub-pixel position of the pixel region by a respective color channel.

Abstract: Systems and methods for configuring an integrated transceiver are disclosed. In one embodiment, very small form factor transceivers can be configured to allow 10 G optical interconnects over distances up to 2 km. Transceiver circuitry can be integrated on a single die, and be electrically connected to a transmitter such as a laser-diode and a receiver such as a photo-diode. In one embodiment, the laser and photo diodes can be edge-operating, and be mounted on the die. In one embodiment, one or both of the diodes can be surface-operating so as to allow relaxation of alignment requirement. In one embodiment, one or both of the diodes can be mounted on a submount that is separate from the die so as to facilitate separate assembly and testing. In one embodiment, the diodes can be optically coupled to a ferrule via an optical coupling element so as to manage loss in certain situations.

Abstract: A compact optical splitter module is disclosed. One type of compact optical splitter module is a planar attenuated splitter module that includes a branching waveguide network having j?1 50:50 splitters that form up to n?2j output waveguides having associated n output ports, wherein only m<n output ports are suitable for transmitting light to the at least one external output device. This provides a 1×m splitter module wherein each output port has the attenuation of a 1×n splitter module, thereby obviating the need for external attenuation. Another type of compact optical splitter module is a direct-connect splitter module that eliminates the need for an optical fiber array when coupling to external optical fibers. Another type of compact optical splitter module is a microsplitter module that serves as device and module at the same time and that eliminates the differentiation between device and module. The integration of device and module also makes manufacturing the microsplitter module cost-effect.

Abstract: A device for optical communication includes at least a conductor circuit and an insulating layer formed and laminated. An optical circuit and an optical path are transmitting an optical signal, and an optical element or a package substrate on which an optical element is mounted. An optical path converting member is disposed at the optical path for transmitting an optical signal so as to transmit the optical signal between the optical element and the optical circuit. The optical path converting member includes a lens and an optical path conversion mirror having an entrance surface, an exit surface and a reflection surface, and the lens is provided at least one position selected from the entrance surface, the exit surface, and inside of the optical path conversion mirror.

Abstract: An edge-lit panel features extractor patterns that produce uniform illumination. The effective density of extractor pattern pixels is adjusted to achieve uniform illumination. A method of adjusting the effective pixel density of extractor pattern pixels to achieve uniform illumination entails adjusting areas of darkness of a grayscale image, then producing a binary image by dithering the grayscale image, and applying an extractor pattern corresponding to the binary image to a surface of the panel. The extractor pixels correspond to pixels of the binary image derived from a dithered grayscale image, with the darkness of the grayscale image increasing with distance from the light source. Effective pixel density is increased to compensate for attenuated output in dim areas. By adjusting gray shading darkness of a grayscale image, pixel density can be adjusted to achieve uniform light emission.

Abstract: A shared light pipe is set forth for transmitting light generated by a message waiting LED in a mobile communication device, in one direction, and transmitting ambient or surrounding light, in an opposite direction, to a light sensor for controlling a display backlight of the device. The light pipe includes an elongated first portion having a first end for receiving and transmitting light and external surfaces for reflecting light there through via total internal reflection (TIR), a second portion coextensive with the first portion for outputting light received at the first end and reflected through the first portion, and a second branch coextensive with the first portion for receiving and transmitting light for output at the first end.

Abstract: In one embodiment, there is disclosed a waveguide medium using total internal reflection to create a relatively sharp (approximately 90°) bend for optical signals traversing the waveguide. A discontinuity of the medium (such as air) is used to create a turning mirror within the waveguide path. By curving the discontinuity, the entire input optical signal is focused into the output portion of the waveguide, thereby compensating for the diffraction loss of the optical signal at the bend. In one embodiment in order to facilitate proper alignment of the masks certain portions of the waveguide on a first mask are extended (widened) beyond their optimum physical size. This extended portion is then used to position an edge of a second mask, such that optical signal scatter caused by the extended portions of the waveguide are compensated for by adjusting the curvature.

Abstract: In a light emitting device, efficiency and stability are improved. A light emitting device 10 includes a three-dimensional photonic crystal 20. The three-dimensional photonic crystal includes a first defect part 70 forming a resonator including an active medium, a second defect part 80 forming a waveguide for taking out light generated by the resonator, a P clad part 40 formed of a P-type semiconductor, and a N clad part 50 formed of a first N-type semiconductor. The second defect part is provided only in the N clad part among the P clad part and the N clad part. At least a part of the second defect part is formed of a second N-type semiconductor and constitutes a heat radiation unit which radiates a heat to the outside.

Abstract: Various embodiments of the present invention are related to photonic systems and methods that can be used to encode data in carrier electromagnetic waves. In one embodiment of the present invention, a method for encoding data in carrier electromagnetic waves is provided. The method comprises: transmitting a number of carrier electromagnetic waves in a first waveguide; coupling one or more of the carrier electromagnetic waves into a resonant cavity of a photonic crystal coupled to the first waveguide; modulating the one or more carrier electromagnetic waves within the resonant cavity in order to generate data encoded electromagnetic waves; and coupling the data encoded electromagnetic waves into a second waveguide.

Abstract: Optical fiber interconnection devices, which can take the form of a module, are disclosed that include an array of optical fibers and multi-fiber optical-fiber connectors, for example, a twenty-four-port connector or multiples thereof, and three eight-port connectors or multiples thereof. The array of optical fibers is color-coded and is configured to optically interconnect the ports of the twenty-four-port connector to the three eight-port connectors in a manner that preserves transmit and receive polarization. In one embodiment, the interconnection devices provide optical interconnections between twenty-four-fiber optical connector configurations to eight-fiber optical connector configurations, such as from twenty-four-fiber line cards to eight-fiber line cards, without having to make structural changes to cabling infrastructure. In one aspect, the optical fiber interconnection devices provide a migration path from duplex optics to parallel optics.

Abstract: An optical selector is provided which enables reliable transmission of a signal from a single or plurality of light output sections to a single or plurality of light input sections.

Abstract: An optoelectric composite wiring module includes: a pair of optical circuit sections, each including an optical element that performs photoelectric conversion and that receives or outputs an optical signal; an optical wiring section including an optical wiring that transmit the optical signal between the pair of optical circuit sections; and an electric wiring section including an electric wiring that transmits an electric power or electric signal that is not related to the photoelectric conversion, the electric wiring section including a first portion being stacked above the optical wiring section and a second portion being separated from and not stacked above each of the pair of optical circuit sections.

Abstract: A door handle apparatus for a vehicle, opening and closing a vehicle door, the door handle apparatus includes an informing portion for visually informing a state of the vehicle door, including a locking/unlocking state thereof, to a user by a decorative light, which is a visible light, an operation detecting portion for optically detecting an active-direct operation to the door handle apparatus by the user based on changes in an detection light, and an optical waveguide for transmitting the decorative light and the detection light, which is inputted from a first end portion of the optical waveguide, to a second end portion of the optical waveguide, the optical waveguide functioning as the informing portion by leaking the decorative light on a transmission path so as to be outwardly emitted and as the operation detecting portion by outputting the detection light from the second end portion of the optical waveguide.

Abstract: The disclosure generally involves an optical (perhaps flat panel) display utilizing backside reflection for time-multiplexed optical shuttering. One display comprises a side-illuminated light guide associated with conditions for total internal reflection. A first surface of the light guide is elastomeric. Disposed against this elastomeric surface is an active layer that selectively deforms the elastomeric surface in locations that can correspond to display pixels. This resulting change in the geometry of the elastomeric surface can be sufficient to defeat the conditions for total internal reflection. When appropriate, light is reflected by the particular deformation and is ejected from another surface of the light guide. In this case, each location that allows light to exit could represent an activated display pixel. In certain situations, color flat panel displays of varying sizes may further implement field sequential color and time-multiplexed optical shuttering.

Abstract: An optical display device, in particular for use in a head-up display or a head-mounted display, comprises an essentially planar light guide, an image-generating system, a first diffraction grating by which light that comes from the image-generating system can be coupled into the light guide, and a second diffraction grating, by which the light can be coupled out again from the light guide. At least one of the two diffraction gratings is a binary-blazed grating having a multiplicity of diffraction structures, which are composed of a multiplicity of individual substructures that ensure a blaze effect and in plan view have the shape of a closed geometrical surface.

Abstract: A reversible optical energy limiting device comprises a waveguide forming an optical path between an input end and an output end, and an optical energy responsive material located in the optical path for reflecting at least a portion of optical energy received from the input end back toward the input end when the optical energy exceeds a predetermined threshold. The optical energy responsive material does not reflect optical energy when it drops below the predetermined threshold, and thus propagation of optical energy from the input end to the output end is automatically resumed when the optical energy drops below the predetermined threshold. The optical energy responsive material may extend across the optical path an acute angle relative to the longitudinal axis of the optical path so that back-reflected light does not re-enter the optical system.

Abstract: A beam coupler assembly for a fiber laser is disclosed. The assembly includes a housing having a sidewall with an interior surface, an exterior surface, a first end and a second end. A first seal extending from the interior surface of the tubular housing and dividing the housing into a first section and a second section is also provided. The first section and second section are environmentally isolated from one another. However, the first seal is substantially optically neutral. An input collimator unit received within the first end of the sidewall of the housing and into the first section and is releasably coupled thereto. An output collimator unit received within the second end of the sidewall of the housing and into the second section and is also releasably coupled thereto.

Abstract: A plurality of optical members (lenses) for use in ultraviolet region are mutually stuck. A fluorine-based organic compound (for example, fluorine-based oil) is provided between them. The periphery of the optical members is sealed with a sealant. As the sealant, an adhesive fluorine resin, for example, a soluble fluorine resin is used.

Abstract: A waveguide retroreflector consists of an end cap with curved output surface attached to a waveguide such as optical fiber. The radius of curvature of the output surface of the end cap matches the length of the end cap so as to retro-reflect a substantial portion of radiation exiting the waveguide, back into the waveguide. A method of fabricating the waveguide retroreflector includes steps of splicing an end cap to a waveguide, heating the free flat surface of the end cap, so that surface tension changes the shape of the end cap to a convex shape due to surface tension, monitoring amount of light reflected off the surface being heated, and stopping applying the heat when the amount of the reflected light approaches a maximum value.

Abstract: A virtual image display device is provided which displays a two-dimensional image for viewing a virtual image in a magnified form by a virtual optical system. The virtual image display device includes an optical waveguide (13) to guide, by internal total reflection, parallel pencil groups meeting a condition of internal total reflection, a first reflection volume hologram grating (14) to diffract and reflect the parallel pencil groups incident upon the optical waveguide from outside and traveling in different directions as they are so as to meet the condition of internal total reflection inside the optical waveguide and a second reflection volume hologram grating (15) to project the parallel pencil groups guided by internal total reflection inside the optical waveguide as they are from the optical waveguide by diffraction and reflection thereof so as to depart from the condition of internal total reflection inside the optical waveguide.

Abstract: A flexible optoelectric interconnect including an optoelectric film, a driving IC, an optical semiconductor device, a heat dissipation plate and a thermally conductive material. The optoelectric film has an electrical interconnect layer made of a single layer and an optical interconnect layer including an optical waveguide core and an optical waveguide clad. The optoelectric film has a through hole extending from a major surface thereof to a rear surface opposite to the major surface. The driving IC is provided on the major surface of the optoelectric film and electrically connected to the electrical interconnect layer, and provided above the through hole in the optoelectric film. The optical semiconductor device is provided on the major surface of the optoelectric film and driven by the driving IC.

Abstract: Disclosed are optical modulators that have two coupling paths or structures between an input port to an output port, at least one of which includes an optical resonator.

Abstract: A spectral filter comprises a planar optical waveguide having at least one set of diffractive elements. The waveguide confines in one transverse dimension an optical signal propagating in two other dimensions therein. The waveguide supports multiple transverse modes. Each diffractive element set routes, between input and output ports, a diffracted portion of the optical signal propagating in the planar waveguide and diffracted by the diffractive elements. The diffracted portion of the optical signal reaches the output port as a superposition of multiple transverse modes. A multimode optical source may launch the optical signal into the planar waveguide, through the corresponding input optical port, as a superposition of multiple transverse modes. A multimode output waveguide may receive, through the output port, the diffracted portion of the optical signal. Multiple diffractive element sets may route corresponding diffracted portions of optical signal between one or more corresponding input and output ports.

Abstract: An apparatus and method for optically detecting the presence of an analyte in a solution is presented. An embodiment comprises a waveguide resonator that is optically coupled to a fluid in a fluidic conduit so that the resonant wavelength of the waveguide resonator is based on the refractive index of the fluid.

Abstract: A light guide of the tapered-waveguide type includes an input slab (30) for expanding a projected image between an input end and an output end, and an output slab (10) arranged to receive rays from the said output end, and to emit them at a point on its face that corresponds to the angle at which the ray is received. The input slab and output waveguide are matched so that all rays injected into the input end undergo the same number of reflections before leaving the output surface. With the invention the input slab (30) is itself tapered slightly towards the output waveguide. This means that input and output waveguides can be made the same length, in the direction of ray travel, and can therefore be folded over each other with no wasted space.

Abstract: It is made possible to provide an optical waveguide system that has a coupling mechanism capable of selecting a wavelength and has the highest possible conversion efficiency, and that is capable of providing directivity in the light propagation direction. An optical waveguide system includes: a three-dimensional photonic crystalline structure including crystal pillars and having a hollow structure inside thereof; an optical waveguide in which a plurality of metal nanoparticles are dispersed in a dielectric material, the optical waveguide having an end portion inserted between the crystal pillars of the three-dimensional photonic crystalline structure, and containing semiconductor quantum dots that are located adjacent to the metal nanoparticles and emit near-field light when receiving excitation light, the metal nanoparticles exciting surface plasmon when receiving the near-field light; and an excitation light source that emits the excitation light for exciting the semiconductor quantum dots.

Abstract: An optical interleaver of a wavelength division multiplexing (WDM) system includes an optical coupler, first and second waveguides, a high reflection mirror, and first and second phase shifters. The coupler divides an input optical signal. The first waveguide branches off from the coupler in a first direction. The second waveguide branches off from the coupler in a second direction for providing an optical path different from that provided by the first waveguide. The high reflection mirror is disposed at an end of the first waveguide for reflecting a first optical signal incident onto the first waveguide. The first phase shifter is disposed at an end of the second waveguide for multiple-reflecting a second optical signal incident onto the second waveguide. The second phase shifter is disposed at the first or second waveguide for adjusting an optical path difference between the first and second waveguides by varying its refractive index.

Abstract: In the band edge region, transmission and reflection of an optical wave can be made very sensitive to the change in radiation wavelength, a change in the modulator material refractive index, and/or a change in the material absorption. Controlling these parameters with the increased level of sensitivity is provided by modulation using the band edge region. A preferred embodiment method of the invention uses a periodic optical structure (i.e., a grating) on top of an optical waveguide structure. The combination of the periodic structure and the optical waveguide is designed so that the reflection and/or transmission of the guided wave have broad pass bands with narrow transition bands. The optical structure is exposed to an incident laser radiation with wavelength in one of the transition bands. Modulation of the incident laser radiation is controlled by the change in refractive index or absorption in the optical guided wave structure produced by the modulation voltage.