Abstract: An electro-optic device, comprising a layer of light-carrying material; and a rib, projecting from the layer of light-carrying material, for guiding optical signals propagating through the device. The layer of light-carrying material comprises a first doped region of a first type extending into the rib, and a second doped region of a second, different type extending into the rib such that a pn junction is formed within the rib. The pn junction extends substantially parallel to at least two contiguous faces of the rib, resulting in a more efficient device. In addition, a self-aligned fabrication process can be used in order to simplify the fabrication process and increase reliability and yield.

Abstract: Provided is a semiconductor optical device, which has a buried heterostructure structure and is formed in a structure capable of reducing a parasitic capacitance to further improve characteristics thereof, and also provided are an optical transmitter module, an optical transceiver module, and an optical transmission equipment. The semiconductor optical device includes a modulator portion for modulating light input along an emitting direction and radiating the modulated light, the modulator portion including: a mesa-stripe structure, which includes an active layer and extends in the emitting direction; and a buried layer provided adjacent to each side of the mesa-stripe structure, in which a distance between a lower surface of the buried layer and a lower surface of the active layer is 20% or more of a distance between the lower surface and an upper surface of the buried layer.

Abstract: A doping profile for a modulator facilitates rapidly changing the carrier density in a waveguide. The carrier density change causes rapid changes in the index of refraction of the waveguide. Example modulators include a ring modulator and a Mach Zender modulator. A charge reciprocating section may be provided to control the amount of injected charge.

Abstract: An improved algorithm for calculating multimode fiber system bandwidth which addresses both modal dispersion and chromatic dispersion effects is provided. The radial dependence of a laser transmitter emission spectrum is taken into account to assist in designing more effective optical transmission systems.

Abstract: The invention relates to an optical modulator, comprising a first waveguide for a signal to be modulated, a second waveguide for a control signal, and an auxiliary waveguide, wherein the auxiliary waveguide is supported by a carrier which can be deflected to change a distance between the first waveguide and the auxiliary waveguide, wherein the carrier also comprises two layers with different coefficients of thermal expansion and the second waveguide is guided in such a way that a temperature of the carrier at least in a section can be manipulated by light transported by the second waveguide. The invention further relates to an integrated optical circuit comprising such an optical modulator, and to a modulation method which can be performed with such a modulator.

Abstract: An optical modulation structure includes a lower cladding layer (102), a first silicon layer (103) integrally formed from silicon of a first conductivity type on the lower cladding layer (102) while including a core (104) and slab regions (105) arranged on both sides of the core (104) and connected to the core, a concave portion (104a) formed in an upper surface of the core (104), and a second silicon layer (109) of a second conductivity type formed on a dielectric layer (108) in the concave portion (104a) so as to fill the concave portion (104a).

Abstract: An optical device includes first and second optical modulators formed on a substrate having electro-optical effect. The first optical modulator includes a first optical waveguide; a first signal electrode configured to provide a first data signal for the first optical waveguide; and a first DC electrode, arranged at an output side of the first signal electrode, and configured to provide first DC voltage for the first optical waveguide. The second optical modulator includes a second optical waveguide; a second signal electrode configured to provide a second data signal for the second optical waveguide; and a second DC electrode provided, arranged at an input side of the second signal electrode, and configured to provide second DC voltage for the second optical waveguide. Input portions of the first and second signal electrodes are arranged at a same side edge of the substrate.

Abstract: An optical modulator having a high stability is provided. In the optical modulator according to the present invention, a phase modulation by an electro-optic effect is made on an optical substrate of an electro-optic material while the setting of an operating point by a thermal-optic effect is made on a planar lightwave circuit (PLC) substrate of quartz, silicon, or the like. Such configuration can suppress the influence of thermal drift or the like because no heat is applied directly to the optical substrate of the electro-optic material. In addition, breakage and warpage of the substrate due to heat are also mitigated. Further, quartz used for the PLC has a low thermal conductivity, approximately one-fifth of that of the LN substrate (approximately 1 W/(m·K)), and therefore, a desired phase difference can be maintained with a low power consumption, and thus, the operating point becomes stabilized.

Abstract: An optical phase modulator having a reduced time drift of an electro-optical response is disclosed. An optical waveguide exhibiting the electro-optic effect includes two serially coupled portions having opposite time drifts of magnitudes of their respective electro-optical responses. As a result, a time drift of an overall electro-optical response of the optical phase modulator is lessened.

Abstract: The multi-channel optical device includes multiple laser cavities that each reflects a different light channel back and forth between reflective components. One of the reflective components is common to all of the laser cavities in that the common reflective component receives the channels from each of the laser cavities and reflects the received channels. The laser cavities also share a multiplexer that receives the channels reflected by the common reflective device and demultiplexes the channels into demultiplexed channels. A portion of the reflective components are partial return devices that each receives one of the demultiplexed channels. Each of the partial return devices transmits a portion of the demultiplexed channel received by that partial return device. The transmitted portion of the demultiplexed channel exits the laser cavity. Additionally, each of the partial return devices reflects a portion of the demultiplexed channel receive by that partial return device.

Abstract: Apparatus and methods that compensate for the thermally-induced drift of the resonance frequency of a closed-loop resonator include, in an exemplary embodiment, a waveguide-based Mach-Zehnder interferometer (MZI) and an overcoupled, waveguide-based microring resonator. The temperature-induced red-shifting ring resonance can be balanced by a spectral blueshift with temperature of the MZI. To stabilize the resonance of the ring at a given wavelength, the change in optical path lengths with temperature of the ring and the MZI should be equal and opposite. The interplay of nonlinear change in phase of ring resonator with temperature and linear change in phase of MZI with temperature, along with matching the period of this phase change, gives rise to perfect oscillation in the combined system resonance with temperature.

Abstract: The present invention discloses an ultra-compact optical modulator comprising at least one resonator on a semiconductor chip. The EO modulator modulates incoming light having a certain wavelength range and comprises a waveguide layer accommodating at least one resonator having a periodic complex refraction index distribution structure defining a periodic defect band-edge and a cladding layer; and at least one electrode; the waveguide layer, the cladding layer and the electrode forming a capacitor structure; such that when an external voltage is applied to the capacitor structure the free carrier concentration in the waveguide layer is controlled, enabling a modulation of the resonator's refractive index; wherein the periodic defect band-edge is selected to be within the wavelength range, enabling a slow-light propagation of the incoming light within the waveguide layer.

Abstract: A dual polarization quadrature modulator includes an input planar lightwave circuit (PLC) configured to deliver coherent light to a polymer-on substrate device including a plurality of electro-optic (E-O) polymer optical modulation waveguides configured to each phase modulate the coherent light, and the E-O polymer optical modulation waveguides output modulated coherent light to an output PLC configured to combine waveguide pairs of phase modulated light into Mach-Zehnder interferometric signals, combine pairs of Mach-Zehnder interferometric signals into quadrature modulated signals. A polarization rotator rotates modulated light from one of the quadrature modulated signals into an orthogonal polarization. The output PLC combines the quadrature-modulated and rotated quadrature modulated light to form a dual polarization, quadrature modulated light signal. The PLCs and the polymer-on-substrate device are integrated onto a single assembly substrate.

Abstract: A low resistivity hybrid organic-inorganic material may include a proportion of charge traps including a trap element indirectly covalently bonded to a donor or acceptor element. The trap element may include tin. The donor or acceptor element may include indium and/or antimony. Bonding includes cross-linking via oxygen bonds and via organic cross-linkers. The material may be formed as a hybrid sol-gel. The material may have optical transmission and refractive index characteristics. The material may be formed as optical cladding proximal to a non-linear optical layer, and may form a portion of a second order nonlinear optical device. The second order nonlinear optical device may include and electro-optic device including an organic chromophore-loaded modulation layer.

Abstract: An optical modulator apparatus and linearization method are disclosed. The optical modulator may include a buffer layer disposed proximate the electro-optical material substrate. The optical modulator may also include physically asymmetric waveguide elements, which may have physically asymmetric waveguide arms or physically asymmetric hot electrodes. The waveguide arms may include first and second waveguide arms having different dimensions, and the hot electrodes may include first and second hot electrodes having different dimensions. Modulator linearization may be achieved by the above-described modulator structure. Modulator linearization may also be achieved by asymmetric external driving of electric fields applied to the waveguide elements, where the waveguide or electrode dimensions may or may not be symmetric.

Abstract: A flexible and optionally highly elastic waveguide capable of propagating and emitting light is disclosed. The flexible waveguide comprises a flexible material having a surface and an end, wherein a first portion of the light is emitted through at least a portion of the surface of the flexible waveguide, and a second portion of the light is emitted through the end. The flexible waveguide can be used, for example as an area illuminator for many applications. Additionally disclosed is a clothing device for providing illumination. The clothing device comprises clothing (or even optionally a sheet) and a light source for providing light. In one embodiment the clothing device comprises the flexible waveguide.

Abstract: A device is disclosed. The device contains a first electro-optical waveguide comprising at least one first grating, a second electro-optical waveguide comprising at least one second grating, a plurality of electrodes disposed adjacent to the first grating and configured to impose an electric field through the first electro-optical waveguide to modify spectra of the first grating, a fiber amplifier configured to propagate a laser radiation between the first electro-optical waveguide and the second electro-optical waveguide, and at least two circulators associated with the fiber amplifier and the first electro-optical waveguide and the second electro-optical waveguide and configured to provide unidirectional propagation of the laser radiation along the fiber amplifier.

Abstract: An optical module including a first optical coupler; a second optical coupler; a first optical waveguide; a second optical waveguide; a first electrode provided on the first optical waveguide; a second electrode provided on the second optical waveguide; a short electrode shorter than the first and second electrodes and provided on the second optical waveguide; and a first high-frequency connector and a second high-frequency connector; wherein, the short electrode provided on the second optical waveguide is coupled to the second high-frequency connector; and the first electrode provided on the first optical waveguide is coupled to the first high-frequency connector.

Abstract: A hybrid integrated module includes a semiconductor die mechanically coupled face-to-face to an integrated device in which the substrate has been removed. For example, the integrated circuit may include an optical waveguide that conveys an optical signal, which is fabricated on a silicon-on-insulator (SOI) wafer in which the back-side silicon substrate or handler has been completely removed. Moreover, an optical device may be disposed on the bottom surface of an oxide layer (such as a buried-oxide layer) in the integrated device, and the geometry and materials in the integrated device may be selected and/or defined so that the optical signal is evanescently coupled between the optical waveguide and the optical device.

Abstract: Provided is a semiconductor integrated circuit. The semiconductor integrated circuit includes a semiconductor pattern disposed on a substrate and including an optical waveguide part and a pair of recessed portions. The optical waveguide part has a thickness ranging from about 0.05 ?m to about 0.5 ?m. The recessed portions are disposed on both sides of the optical waveguide part and have a thinner thickness than the optical waveguide part. A first doped region and a second doped region are disposed in the recessed portions, respectively. The first and second doped regions are doped with a first conductive type dopant and a second conductive type dopant, respectively. An intrinsic region is formed in at least the optical waveguide part to contact the first and second doped regions.

Abstract: Photonic devices and techniques based on tunable single sideband (SSB) modulation in whispering gallery mode resonators formed of electro-optic materials to construct RF or microwave receivers.

Abstract: An optical waveguide device using a thin substrate having an electro-optical effect and having a thickness of 10 ?m or less, in which, even when the thin substrate is adhered to a supporting substrate, breakage of the thin substrate or supporting substrate is suppressed, and performance deterioration such as optical loss due to fine cracks is also suppressed. The optical waveguide device includes a thin substrate, which has an electro-optical effect and a thickness of 10 ?m or less, and in which an optical waveguide is formed, and a supporting substrate that is adhered to the thin substrate through an adhesion layer. A structure is formed in a thin-substrate side surface of the supporting substrate, and the supporting substrate is annealed at a high temperature that is equal to or lower than the Curie temperature after forming the concavo-convex structure and before being adhered to the thin substrate.

Abstract: A semiconductor optical device includes a first optical waveguide including first, second, and third sections; a second optical waveguide including fourth, fifth, and sixth sections; an input optical coupler; and an output optical coupler. The first and second optical waveguides and the input and output optical couplers each include a first cladding layer composed of an n-type semiconductor and a core layer. The second and fifth sections each include an intermediate semiconductor layer on the core layer, and a second cladding layer composed of an n-type semiconductor. The first, third, fourth, and sixth sections and the input and output optical couplers each further include a third cladding layer on the core layer. At least one of the third cladding layers includes a first cladding section on the core layer and a second cladding section on the first cladding section. The second cladding section is composed of a semi-insulating semiconductor.

Abstract: A Mach-Zehnder interferometer type optical modulator includes first and third optical waveguides; input and output optical couplers; and a phase shifting section disposed between the input and output optical couplers. The phase shifting section includes first and second optical waveguide structures each including an n-type semiconductor section, a core layer and a cladding layer. The cladding layer of the first optical waveguide structure includes a first section disposed on the core layer, and second and third sections disposed on the first section. The second and third sections are juxtaposed to each other in a direction that intersects a waveguiding direction. The first and second sections are composed of a p-type semiconductor, and the third section is composed of an undoped semiconductor.

Abstract: An optical modulator including: a substrate which has electro-optic effect; a Mach-Zehnder optical interferometer which is formed in the substrate and which includes a first waveguide and a second waveguide; a signal electrode which applies an electrical field to the Mach-Zehnder optical interferometer through being supplied with an electric signal corresponding to a signal for optical modulation; a ground electrode formed apart from the signal electrode; and a conductor section which is narrow in a middle thereof along the light propagating direction and which gradually becomes wider towards the starting end and the terminating ends thereof along the light propagating direction in an interacting portion at which the electric field applied by the signal electrode interacts with light propagating through the first waveguide and the second waveguide.

Abstract: An optical modulator and a method for manufacturing an optical modulator are provided.

Abstract: A semiconductor optical modulator that includes a first semiconductor optical waveguide having a laminated structure including a core layer, a first clad layer, a second clad layer, and a barrier layer, the first clad layer and the second clad layer being disposed below and above the core layer, the barrier layer being inserted between the second clad layer and the core layer; a second semiconductor optical waveguide having a laminated structure in which the second clad layer has a p-type semiconductor penetrating locally through a n-type semiconductor in a laminated direction in the laminated structure of the first semiconductor optical waveguide; a first electrode connected to the first clad layer of the first semiconductor optical waveguide; and a second electrode electrically connecting the second clad layer of the first semiconductor optical waveguide and the p-type semiconductor of the second clad layer of the second semiconductor optical waveguide.

Abstract: An integrated circuit that includes an optical waveguide defined in a semiconductor layer is described. In this integrated circuit, light is coupled between the optical waveguide and an optical modulator, which is disposed on the optical waveguide, using 3-dimensional (3-D) taper structures that are proximate to the ends of the optical modulator. The cross-sectional areas of these 3-D taper structures transition, over a distance, from that of the optical waveguide (distal from the optical modulator) to that of optical modulator (proximate to the ends of the optical modulator). In this way, a spatial extent of an optical mode in the optical waveguide and a spatial extent of the optical mode in the optical modulator may be approximately matched to reduce the optical loss when the light is coupled to or from the optical modulator.

Abstract: To provide an optical modulator having a reduced size and reduced power consumption and capable of being easily connected to a waveguide and a method of manufacturing the optical modulator. The optical modulator has at least semiconductor layer (8) having a rib-shaped portion and doped so as to be of a first conduction type, dielectric layer (11) laid on first-conduction-type semiconductor layer (8), and semiconductor layer (9) laid on dielectric layer (11), having the width at the side opposite from dielectric layer (11) increased relative to the width of the rib-shaped portion, and doped so as to be of a second conduction type.

Abstract: An optical waveguide device having a Mach-Zehnder type waveguide formed on a substrate is provided in which a slope of two waveguides input to an optical coupler on an output side of the Mach-Zehnder type waveguide is 0 degrees, a waveguide of the optical coupler after being coupled by the optical coupler is a multi-mode waveguide, and the waveguide which is output from the optical coupler is a three-branched waveguide including an output main waveguide and two output sub waveguides interposing the output main waveguide therebetween.

Abstract: A solid memory may include a recording layer including Ge, Sb and Te as major components. The recording layer may include a superlattice. The recording layer may include multi-layers each having a parent phase showing a phase transformation in solid-states, the phase transformation causing change in electrical property of the recording layer. The recording layer may include an Sb2Te3 layer that includes at least one period of a first lamination of a first Te-atomic layer, a first Sb-atomic layer, a second Te-atomic layer, a second Sb-atomic layer, and a third Te-atomic layer in these order, a GeTe layer that includes at least one period of a second lamination of a fourth Te-atomic layer and a Ge-atomic layer, and an Sb layer that includes a plurality of Sb-atomic layers.

Abstract: An optical phase modulator includes a main Mach-Zehnder interferometer having first and second main optical waveguide path arms, whose initial phase difference in the used wavelength is ?, a first sub Mach-Zehnder interferometer having first and second sub optical waveguide path arms that are formed in the first main optical waveguide path arm, whose initial phase difference in the used wavelength is 0, and a second sub Mach-Zehnder interferometer having third and fourth sub optical waveguide path arms that are formed in the second main optical waveguide path arm, and whose initial phase difference in the used wavelength is 0. Of each of the main optical waveguide path arms and the sub optical waveguide path arms, at least the portions where high-frequency electrodes are formed are constructed using semiconductor waveguide paths, and reduce the effects of frequency chirping caused by an orthogonal component due to light absorption in the semiconductor.

Abstract: Included are a first modulator, a second modulator, a first optical amplifier that amplifies an output of the first modulator at an amplification factor based on a first bias signal, a second optical amplifier that amplifies an output of the second modulator at an amplification factor based on a second bias signal, an optical phase adjuster that phase-rotates an output of the second optical amplifier, an optical multiplexer that multiplexes an output of the first optical amplifier with an output of the optical phase adjuster, and a second bias corrector that generates a first pulse signal and a second pulse signal, which are complementary to each other, and obtains a first bias value and a second bias value based on a change of strength of an output signal of the optical multiplexer. The first and second pulse signals are superimposed on the first and second bias signals, respectively.

Abstract: A controllable optical ring resonator, a photonic system and a method of controlling an optical ring resonator employ control electrodes periodically spaced apart along a closed loop optical path of an optical waveguide. The controllable optical ring resonator includes the optical waveguide and a plurality of the periodically spaced control electrodes. The photonic system includes an input optical waveguide segment and the controllable optical ring resonator adjacent and optically coupled to the segment. The method includes providing the plurality of periodically spaced control electrodes, providing an optical signal within the optical path, and addressing one or more of the control electrodes to interact with the optical signal within the optical path.

Abstract: A method is provided for visual inspection of an array of interferometric modulators in various driven states. This method may include driving multiple columns or rows of interferometric modulators via a single test pad or test lead, such as test pad, and then observing the array for discrepancies between the expected optical output and the actual optical output of the array. This method may particularly include, for example, driving a set of non-adjacent rows or columns to a state different from the intervening rows or columns and then observing the optical output of the array.

Abstract: An apparatus includes an optical semiconductor element comprising: a waveguide into which input light is input; a plurality of ring modulators that have different optical perimeter lengths and are optically coupled to the waveguide; and a control unit configured to selectively apply a modulation signal to at least one of the plurality of ring modulators having a resonant wavelength that is the same as a wavelength of the input light.

Abstract: The present invention relates to an optical control device capable of achieving an accurate match of modulation timing and modulation intensity between optical waves propagating through optical waveguides disposed between a plurality of signal electrodes in an optical control device using an anisotropic dielectric substrate.

Abstract: A method of processing data is provided that includes receiving a plurality of binary electronic signals and generating an optical signal by a number of lasers that is equal to or greater than the number of binary electronic signals. The optical signal is generated at one of a plurality of intensity levels, and each intensity level represents a particular combination of bit values for the plurality of binary electronic signals. The optical signal is converted into an electronic signal having the plurality of intensity levels. An apparatus for processing data is provided that includes a plurality of lasers configured to emit light at a plurality of frequencies, and a plurality of modulators configured to receive a plurality of binary electronic signals and to modulate the light emitted by the lasers. An apparatus for transmitting data is provided that includes a photo receiver and an electronic signal generator.

Abstract: The designed resonator system comprises a light source generating device for outputting a light source and a resonating cavity device. The resonating cavity device includes: a first waveguide with an input end for receiving the light source; a first resonator disposed adjacent to the first waveguide for receiving the light source coupled from the first waveguide in order to generate a resonating light source; a second waveguide having one end disposed adjacent to the first resonator, an adapting end for receiving the resonating light source coupled from the first resonator, and an output end; and an electro-optic modulator disposed adjacent to the other end of the second waveguide for receiving the resonating light source coupled from the second waveguide and generating an optical modulating signal by an electrical modulating signal, and the optical modulating signal is outputted from the output end of the second waveguide.

Abstract: In an optical waveguide device, in a cross direction intersecting an extension direction of waveguide sections, one or more bridge portions of a ground electrode closer to a center of stress distribution of a stress due to a support member, and one or more bridge portions of a ground electrode farther from the center of stress distribution are formed with different shapes. The structure of the ground electrodes is devised so that a stress negating the difference in stress characteristics between the plurality of waveguide sections, generated by the stress applied from the support member to a substrate, is applied from the ground electrode to the substrate.

Abstract: An optical modulator comprises a substrate having an electro-optical effect, an optical waveguide formed in the substrate, a buffer layer provided above the optical waveguide, a semiconductor film provided above the buffer layer and having an aperture at a top of the optical waveguide, and an electrode provided above the buffer layer and electrically coupled to the semiconductor film.

Abstract: There is provided an optical device including a plurality of Mach-Zehnder modulators; and an input branching waveguide to split an input light so as to direct the resulting light to the plurality of Mach-Zehnder modulators; the Mach-Zehnder modulator comprising: a splitter coupled to the input branching waveguide; pair of waveguides coupled to the splitter; a combiner coupled to the pair of waveguides; and a signal electrode to apply signals to the pair of waveguides; wherein the splitters are disposed in a different orientation to each other.

Abstract: The invention relates to an optical waveguide and a semifinished product for producing an optical waveguide having optimized diffraction properties, comprising a trench structure that has a radius-dependent graded refractive index curve and/or a concentric depressed refractive index profile within a core zone (2) and/or within a cladding zone (4). In one embodiment of the optical waveguide and semifinished product, the structure is formed from a succession of differently doped regions containing dopants that are introduced into a base matrix and lower and/or increase the refractive index.

Abstract: A method involving: providing an optical waveguide made of a semiconductor material and having a region that is doped by a deep level impurity which creates deep level states in a bandgap in the semiconductor material, the deep level states characterized by an occupancy; passing an optical signal through the optical waveguide and between the region doped by the deep level impurity; and modulating the occupancy of the deep level states to thereby modulate the optical signal.

Abstract: An electromagnetically responsive element includes sets of arrangements of self-resonant bodies, such as atoms or quantum dots that form an effective dielectric constant, typically at or near a resonance.

Abstract: A tunable Radio Frequency (RF) filter device includes a tunable optical source generating an optical carrier signal, and a modulator coupled to the tunable optical source and modulating the optical carrier signal with an RF input signal. The tunable RF filter device may include first and second optical waveguide paths coupled to the modulator and having first and second dispersion slopes of opposite sign from each other, one or more of the first and second optical waveguide paths comprising an optical splitter and combiner pair therein, and an optical-to-electrical converter coupled to the first and second optical waveguide paths and generating an RF output signal with a frequency notch therein based upon the tunable optical source.

Abstract: A tunable Radio Frequency (RF) filter device includes a tunable optical source configured to generate an optical carrier signal, and a modulator coupled to the tunable optical source and configured to modulate the optical carrier signal with an RF input signal. The tunable RF filter device may also include first and second optical waveguides coupled to the modulator and having first and second dispersion slopes of opposite sign, and an optical-to-electrical converter coupled to the first and second optical waveguides and configured to generate an RF output signal with a frequency notch therein based upon the tunable optical source.

Abstract: An optical set-reset (SR) latch is formed from a first electroabsorption modulator (EAM), a second EAM and a waveguide photodetector (PD) which are arranged in an optical and electrical feedback loop which controls the transmission of light through the first EAM to latch the first EAM in a light-transmissive state in response to a Set light input. A second waveguide PD controls the transmission of light through the second EAM and is used to switch the first EAM to a light-absorptive state in response to a Reset light input provided to the second waveguide PD. The optical SR latch, which may be formed on a III-V compound semiconductor substrate (e.g. an InP or a GaAs substrate) as a photonic integrated circuit (PIC), stores a bit of optical information and has an optical output for the logic state of that bit of information.

Abstract: A high speed silicon-based optical modulator with control of the dopant profiles in the body and gate regions of the device reduces the series resistance of the structure without incurring substantial optical power loss. That is, the use of increased dopant values in areas beyond the active region will allow for the series resistance to be reduced (and thus increase the modulating speed of the device) without incurring too large a penalty in signal loss. The dopant profiles within the gate and body regions are tailored to exhibit an intermediate value between the high dopant concentration in the contact areas and the low dopant concentration in the carrier integration window area.

Abstract: A first apparatus for displaying a color image comprises an electro-optic display (1002) having a plurality of pixels, each of which can be independently set to a light-transmissive optical state or a substantially opaque optical state, and lighting means (1006) arranged to flash separate pulses of light of at least two differing colors on to one surface of the electro-optic display (1002). A second apparatus for generating pulses of light of differing colors comprising a light source and a filter assembly comprising first (1100) and second (1106) electro-optic layers each having a light-transmissive state and a colored state, the two colored states being different, and electrodes to switch these layers between these states.