Abstract: A microchip may include an optical signal routing system. The optical routing system may include a distribution waveguide coupled to a light source and signaling waveguides interconnecting source and destination locations. A directional coupler may be used to couple and modulate light from the distribution waveguide to a signaling waveguide at a source location. A photodetector may be used to convert light signals from the source location into electrical signals at the destination.

Abstract: An optical device having a photonic band gap element operative such that the refractive index can be varied through application of an electrical signal. This enables the manufacture of tuneable lasers, optical add/drop multiplexers and tuneable optical wavelength converters.

Abstract: An electro-optic modulator structure for particular use in narrowband optical subcarrier systems. A traveling wave is established across the active region of the device, instead of a standing wave. This is accomplished through the use of a directional resonator structure that prevents reverse-traveling waves from being established within the resonator. Hence, the electric field is applied to the traveling optical wave in a similar fashion to a traveling-wave modulator, except that the traveling wave has a much greater amplitude due to the build-up of energy inside the resonator. Since the modulator is operated in a traveling-wave fashion, it can be tuned to operate at any frequency using tuning elements, regardless of the length of the active region. Furthermore, the microwave and optical signals can be velocity-matched to mitigate optical transit time effects that are normally associated with a resonant modulator utilizing a standing-wave electrode structure.

Abstract: A tuneable optical fibre comprising a long-period Bragg grating (5) written in a portion of an optical waveguide (10) comprising a core and an optical cladding (11), characterised in that the portion of the waveguide comprising the grating (5) is at least partially immersed in an external environment consisting of two distinct sections, a first section (1) whose refractive index is higher than that of the optical cladding (11) and a second section (2) whose refractive index is lower than that of the optical cladding (11), the long-period grating being at least partially immersed in one of the said sections so as to almost independently tune the wavelength and/or the contrast of the spectral response of the filter.

Abstract: Optical systems are provided. One such system includes an optical transmission path that is defined, at least partially, by a variable optical delay system. The variable optical delay system incorporates a variable refractive index component that is arranged to receive an optical signal. The variable optical delay system provides a control input to adjust a refractive index of the variable refractive index component so that latency of the optical signal can be altered. Methods and other systems also are provided.

Abstract: An optical waveguide comprising an MgO substrate 10, and a slab waveguide layer 24 formed on the MgO substrate 10 and including a core layer 18 of a ferroelectric or an antiferroelectric, further comprises a stress alleviating layer 12 which substantially lattice-matches with the MgO substrate and the slab waveguide layer 24 and has an average thermal expansion coefficient in the range of 7.0×10?6-14.0×10?6/° C. at the room temperature to 700° C. Accordingly, the optical waveguide device utilizing the magnesium oxide substrate can be formed without breaking the optical waveguide layer and the magnesium oxide substrate itself.

Abstract: A method and system are disclosed for switching at least part of a light signal out of a first waveguide by a Bragg grating formed from an electro-optic effect in the first waveguide. The Bragg grating is created by turning on a series of electrodes on each side of the first waveguide. The electrodes create electric fields in the core of the first waveguide which raise the refractive index in certain regions of the core. When the electric fields are tilted and evenly spaced apart, at least part of a light signal propagating through the waveguide, at a predetermined wavelength, is reflected out of the first waveguide. The reflected light signal can be switched back into a second waveguide by use of another Bragg grating. When the electric fields are off in the first waveguide the light signal, including the part of the light signal having the predetermined wavelength, continues straight on through the Bragg grating area.

Abstract: A polarization transformer/PMD compensator chip contains a differential TE-TM phase modulator at its input. The modulator generates a TE-TM phase modulation. The mode converter voltages are driven with driving signals that are free of DC components. DC drift is thereby safely avoided.

Abstract: An apparatus/method for producing fabric-like electronic circuit patterns created by methodically joining electronic elements using textile fabrication-like methods in a predetermined arrangement.

Abstract: A silicon-based electro-optic modulator is based on forming a gate region of a first conductivity to partially overly a body region of a second conductivity type, with a relatively thin dielectric layer interposed between the contiguous portions of the gate and body regions. The modulator may be formed on an SOI platform, with the body region formed in the relatively thin silicon surface layer of the SOI structure and the gate region formed of a relatively thin silicon layer overlying the SOI structure. The doping in the gate and body regions is controlled to form lightly doped regions above and below the dielectric, thus defining the active region of the device. Advantageously, the optical electric field essentially coincides with the free carrier concentration area in this active device region. The application of a modulation signal thus causes the simultaneous accumulation, depletion or inversion of free carriers on both sides of the dielectric at the same time, resulting in high speed operation.

Abstract: An integrated chromatic dispersion compensator for optical signals in optical communication networks, comprising a plurality of cascaded stages of optical dispersion elements arranged in the form of a lattice filter structure, is characterized by at least one tapping device disposed between consecutive stages of the optical dispersion elements for tapping inter stage signals, feeding each tapped inter stage signal into a separate feedback loop, which in turn is feeding adaptation parameters into at least one of the stages of the optical dispersion elements preceding the corresponding tapping device of the inter stage signal. The invention presents a compact dispersion compensator that can dynamically be adapted to varying dispersion situations and that is capable of compensating the chromatic dispersion of a multitude of data channels at the same time.

Abstract: Optoelectronic and photonic devices are formed by employing polymer materials that have a lower glass transition temperature (Tg) than the nominal operating temperature. By using such materials, the local or segmental mobility is increased so that local stress is eliminated or minimized on the polymer material, making performance more robust. The current invention involves use of a polymer in an optical device in an operating temperature range in the region above Tg, where the polymer segments between crosslinks are allowed local freedom of movement; however, large-scale movement of the material may be restricted by the crosslinked structure of the polymer material.

Abstract: A method of attaching electrodes to optical substrates with embedded waveguides includes applying the electrode pattern to a separate superstrate from the electro-optic material containing the waveguide. This allows for the change of the index of refraction and/or the dipole moment of an electro-optic material using low voltages. In0 addition, the electrode superstrate can be detached from the waveguide substrate and repositioned and aligned to different waveguides. Removable electrodes add flexibility and increase yield by allowing the electrodes to be re-aligned to the waveguides when improper alignment occurs.

Abstract: The index of refraction of waveguide structures can be varied by altering carrier concentration. The waveguides preferably comprise semiconductors like silicon that are substantially optically transmissive at certain wavelengths. Variation of the carrier density in these semiconductors may be effectuated by inducing an electric field within the semiconductor for example by apply a voltage to electrodes associated with the semiconductor. Variable control of the index of refraction may be used to implement a variety of functionalities including, but not limited to, tunable waveguide gratings and resonant cavities, switchable couplers, modulators, and optical switches.

Abstract: The optical domain optical signal sampling device comprises an electrical sampling pulse source and an electrically-controlled optical modulator. The electrically-controlled optical modulator comprises electro-optical material, an optical waveguide located in the electro-optical material and including a bifurcated region, and electrodes disposed along the bifurcated region. The optical waveguide is arranged to receive an optical signal-under-test. At least one of the electrodes is connected to receive electrical sampling pulses from the electrical sampling pulse source. The electrical sampling pulses generate an electric field between the electrodes that differentially changes the refractive index of the electro-optical material in the bifurcated region of the optical waveguide to sample the optical signal-under-test.

Abstract: A push-pull thermooptic interferometer switch can be controlled using only one control lead and one drive signal per switch. Advantageously, using only control signal lead and one electrical driver per switch can greatly reduce the complexity of the electronics needed to drive a switch array. The single control lead push-pull thermooptic interferometer switch can be driven by controllable voltage or current signals. The connections of the control and other signal leads to an array of these switched can be made in a planar manner without the need for crossover paths.

Abstract: A resonant optical modulator includes an electro-optical substrate, an optical waveguide formed in the substrate and having a variable index of refraction, and an active modulator electrode formed on the substrate in relation to the waveguide to effect electro-optical variation of the index of refraction upon application to the electrode of a modulating signal. An interface port formed on the substrate provides the modulating signal to the electrode from a signal source and has an impedance. An electrical structure, formed on the substrate and coupled to the interface port and the electrode, makes an impedance of the optical modulator substantially equal to the impedance of the signal source. The electrical structure includes a delay line and a stub formed on the substrate.

Abstract: In a method of fabricating a traveling wave optical modulator, an optical waveguide structure having an optical waveguide and a signal electrode path extending from a signal input to a termination output is formed. The signal electrode path is modified to include a customized signal electrode having a transmission line characteristic substantially matching a target transmission line parameter value. In another aspect, a traveling wave optical waveguide structure includes an optical waveguide and a signal electrode path. The signal electrode path extends from a signal input to a termination output and is defined by an electrode seed structure. The electrode seed structure is exposed for subsequent electrode formation and has a transmission line characteristic detrimental to proper propagation of an electrical modulation signal.

Abstract: The present invention provides for polarization independence in electrooptic waveguides. Specifically, in accordance with one embodiment of the present invention, an electrooptic waveguide for an optical signal is provided. The waveguide comprises a plurality of control electrodes, an optical waveguide core defining a primary axis of propagation, and an electrooptic cladding at least partially surrounding the core. The control electrodes are positioned to generate a contoured electric field across the cladding. The cladding is poled along a poling contour. The contoured electric field and/or the poling contour are asymmetric relative to a plane intersecting the waveguide core and extending along the primary axis of propagation. The electrooptic cladding defines at least two cladding regions on opposite sides of the waveguide core.

Abstract: An electro-optic modulator (300) comprises a substrate (310) made of a material which has an electro-optic effect and a pyroelectric effect. In the substrate (310), an optical waveguide (320) is formed to have at least a pair of optical paths. On the substrate (310) and on the optical waveguide (320), a transparent buffer layer (330) is formed to cover the optical waveguide (320). On the buffer layer (330), first and second electrodes (341, 342) are formed so that the first and the second electrodes (341, 342) are arranged to cause refractive index changes in the pair of optical paths in response to electrical fields surrounding the electro-optic modulator (300). The buffer layer (330) is a mutual diffusion layer. The mutual diffusion layer is made from laminated films comprised of at least one transparent insulator film and at least one transparent conductor film but has no clear boundary between the transparent insulator film and the transparent conductor film.

Abstract: An optical waveguide device has an optical waveguide substrate and a supporting substrate. The optical waveguide substrate has a main body made of an electro-optic material and having a first main face and a second main face, an optical waveguide formed in or on the main body and an electrode formed on the side of the first main face of the main body. The supporting substrate is joined with the second main face of the main body. A low dielectric portion with a dielectric constant lower than that of the electro-optic material is formed in the supporting substrate.

Abstract: A method for operating a planar lightwave circuit at a constant power consumption, comprises providing a matrix of integrated active elements, heating independently each active element with a separate heating power, and cooperatively operating the heating powers of the active elements to keep a sum of the operating heating powers constant in time independently on the dynamic operation of the element. The active element has two connecting configurations and is operative to have a phase change in a light beam passing through each of the connecting configurations, both connecting configurations being constantly heated. The active element is operable in both analog and digital modes with a constant power consumption.

Abstract: In an optical switch with a mirror, the inclination angle of which varies depending on an application voltage, a low-frequency signal is superimposed on the application voltage, and a low-frequency component is detected in output light reflected on the mirror. Then, an application voltage is increased/decreased based on the detected low-frequency component.

Abstract: The present invention relates to an electrode structure, which comprises a substrate provided with an electrode formed thereon, wherein the substrate comprises a layer of a fluorine-containing polyimide and a layer of a fluorine-free resin is interposed between the polyimide layer and the electrode and, in particular, to the foregoing electrode structure, wherein the electrode comprises a gold layer as the outermost or surface layer and an aluminum layer interposed between the substrate and the gold layer. The electrode structure of the present invention never causes any peeling off of the electrode due to insufficient adhesion of the electrode to the substrate, the structure has sufficiently high strength and therefore the boundary between the substrate and the electrode formed thereon is not destroyed by the energy of ultrasonics applied thereto.

Abstract: A variable dispersion compensator includes an optical waveguide, a temperature controller. The optical waveguide has a chirped grating having a Bragg wavelength changing along the longitudinal direction of the grating. A temperature distribution T1(x) is applied to a central portion of the grating, defined as a region where a distance x from an end of the grating is a range of 20 % to 80 % of total length of the grating. Temperature distribution T2(x) and T3(x) are applied to end portions of the grating, defined as two regions extending from respective ends of the grating to the central region, respectively. At least one of T2(x) and T3(x) has a distance dependence different from that of the T1(x).

Abstract: A silicon-based electro-optic modulator is based on forming a gate region of a first conductivity to partially overly a body region of a second conductivity type, with a relatively thin dielectric layer interposed between the contiguous portions of the gate and body regions. The modulator may be formed on an SOI platform, with the body region formed in the relatively thin silicon surface layer of the SOI structure and the gate region formed of a relatively thin silicon layer overlying the SOI structure. The doping in the gate and body regions is controlled to form lightly doped regions above and below the dielectric, thus defining the active region of the device. Advantageously, the optical electric field essentially coincides with the free carrier concentration area in this active device region. The application of a modulation signal thus causes the simultaneous accumulation, depletion or inversion of free carriers on both sides of the dielectric at the same time, resulting in high speed operation.

Abstract: An electrical variable optical attenuator (10) includes a housing, an attenuating device (3), an optical module (4), and an electrical controlling unit (5). The housing encases the attenuating device, optical module and electrical controlling unit. The electrical controlling unit includes an electrical resistor (57), a terminal holder (56), and a stepping motor (55). The terminal holder includes a plurality of terminals (562), and a plurality of terminal sleeves (563) depending from an insulating plate (561). The terminal holders are fittingly received in positioning holes (131) defined in the housing, so that the terminals can electrically connect the stepping motor and the electrical resistor with an external power supply. The insulating plate is made of rubber, which is softer than a material of the housing. A diameter of the terminal sleeves is slightly greater than a diameter of the positioning holes. Thus the terminal sleeves provide an airtight and watertight seal.

Abstract: Our invention relates generally to an optical switch (31) and an optical router (10) to rapidly route signals from particular channels (22, 24) within an optical band by using optical switches (20) which utilize a controlled whispering gallery mode (WGM) resonance of dielectric microspheres (S1, S2, S3) to optically switch signals. Another invention relates to optical filters which use a WGM resonate structure (150) to isolate and switch specific optical signals between waveguides (F1, F2). In other inventions, the filter (100) is switched “on/off” by signal loss within a WGM resonate structure (150) which disrupts the WGM resonance; the filter (100) isolates and switches a specific wavelength signal from among a group of signals of different wavelengths; and is switched “off” by adjusting the index of refraction of the resonate structure to become substantially similar to the index of refraction of the surrounding medium.

Abstract: In order to provide a low power duobinary modulator for the long reach 10 Gb/s metro space that is relatively small and relatively inexpensive to make, a method of operating a Multiple Quantum Well (MQW) III-V Mach-Zehnder (MZ) optical modulator to have it provide a high-quality duobinary signal is provided. The method of operating the MQW III-V MZ optical modulator provided by the invention makes possible a high-quality duobinary modulator that has substantially balanced ‘on’ states. That is to say, both duobinary ‘on’ states are characterized by having respective output signals with substantially equivalent: peak intensities; high extinction ratios; and low frequency chirp.

Abstract: A programmable chirp optical modulator is provided having programs modes of chirp. The modulator includes an optical modulation chip substrate having an electrooptic property; a waveguide that runs across the optical modulation chip, wherein the waveguide includes a first main channel branching into separate parallel first and second waveguide arms that combine into a second main channel; a first coplanar-strip electrode overlying and running along the first waveguide arm; a second electrode overlying and running along the second waveguide arm; and at least one programmable electrode overlying the substrate and adjacent to the second electrode on a side of the second coplanar-strip electrode opposite a side of the second coplanar-strip electrode where the first coplanar-strip electrode is located. The at least one programmable electrode runs in parallel with the second electrode as the second electrode runs along the second waveguide arm.

Abstract: The present invention provides for polarization independence in electrooptic waveguides. Specifically, in accordance with one embodiment of the present invention, an electrooptic waveguide for an optical signal is provided. The waveguide comprises a plurality of control electrodes, an optical waveguide core defining a primary axis of propagation, and an electrooptic cladding at least partially surrounding the core. The control electrodes are positioned to generate a contoured electric field across the cladding. The cladding is poled along a poling contour. The contoured electric field and/or the poling contour are asymmetric relative to a plane intersecting the waveguide core and extending along the primary axis of propagation. The electrooptic cladding defines at least two cladding regions on opposite sides of the waveguide core.

Abstract: A method of attaching electrodes to optical substrates with embedded waveguides includes applying the electrode pattern to a separate superstrate from the electro-optic material containing the waveguide. This allows for the change of the index of refraction and/or the dipole moment of an electro-optic material using low voltages. IN addition, the electrode superstrate can be detached from the waveguide substrate and repositioned and aligned to different waveguides. Removable electrodes add flexibility and increase yield by allowing the electrodes to be re-aligned to the waveguides when improper alignment occurs.

Abstract: Optical modulators are provided. A representative optical modulator includes an optical medium that is adapted to propagate optical signals. An array of lattice sites are arranged in the optical medium, with at least some of the lattice sites exhibiting lower refractive indexes than the refractive index of the optical medium. Preferably, a first of the lattice sites incorporates a first optical component that is moveable relative to the optical medium. By moving the first optical component relative to the optical medium, a propagation characteristic of the optical medium can be altered. Optical systems, methods and other optical modulators also are provided.

Abstract: Controllable fiber optic attenuators and attenuation systems are disclosed for controllably extracting optical energy from a fiber optic, and therefore attenuating the optical signal being transmitted through the fiber optic. Material removed from a portion of the fiber optic exposes a side surface through which optical energy can be extracted. The portion of the fiber is suspended between two support points, and a controllable material is formed over the surface for controllably extracting optical energy according to a changeable stimulus applied thereto, which affects the refractive index thereof. In one embodiment, the changeable stimulus is light energy from a light source having a different wavelength from the wavelength of the optical energy of interest.

Abstract: The present invention relates to a method for trimming birefringence of an integrated optical device with at least one waveguide having a birefringence characteristic, comprising the steps of providing at least one electrode on top of the waveguide, and applying power equal to or above a predetermined power level to said at least one electrode for causing a change of the refractive indices of the waveguide.

Abstract: The present invention provides for polarization independence in electrooptic waveguides. Specifically, in accordance with one embodiment of the present invention, an electrooptic waveguide for an optical signal is provided. The waveguide comprises a plurality of control electrodes, an optical waveguide core defining a primary axis of propagation, and an electrooptic cladding at least partially surrounding the core. The control electrodes are positioned to generate a contoured electric field across the cladding. The cladding is poled along a poling contour. The contoured electric field and/or the poling contour are asymmetric relative to a plane intersecting the waveguide core and extending along the primary axis of propagation. The electrooptic cladding defines at least two cladding regions on opposite sides of the waveguide core.

Abstract: A non-liner electron-optic polymer based, integrated optic, electron-optic device utilizing a non-liner electron-optic polymer for the optical wave guide core layer sandwich between two very thin optically transparent electrically conductive charge sheet poling electrode layers which are, in turn, sandwiched between two electrically passive polymer optical wave guide cladding layers.

Abstract: An optical switch has a slab waveguide for eliminating polarization dependency between a TE mode optical signal component and a TM mode optical signal component. Disposed on one end of the waveguide is a first deflection portion formed of electro-optical crystal and disposed on the other end of the waveguide is a second deflection portion also formed of electro-optical crystal, in which a half waveplate is disposed at a substantially center portion between the two ends of the slab waveguide. The optical signal propagated from the first deflection portion to the second deflection portion has a TE mode component and a TM mode component thereof switched with respect to each other by the half waveplate.

Abstract: An optical device with at least one junction formed by an intersection of at least two waveguides may be used to tap, and/or attenuate an optical signal. The waveguides may be formed from various materials such as polymers and other combinations of monomers. Internal reflection produced at each junction between the waveguides in response to heating from a thin film electrode will direct a portion of an optical signal from one of the waveguides to another waveguide. Internal reflection at each junction may be used to selectively tap and/or attenuate power level of an optical signal.

Abstract: A variable optical device for selectively controlling propagation of light within an optical waveguide. The optical device comprises: a relief modulation defining a grating disposed proximal the waveguide and having a respective grating index of refraction nG; a matrix surrounding at least the relief modulation, the matrix having an index of refraction nEO that is controllable, in response to a selected stimulus between a first value that is substantially equal to the grating index of refraction nG, and a second value that is different from nG; and at least one electrode for supplying the selected stimulus to the matrix-grating system.

Abstract: One or more single mode waveguide devices are fiber coupled such that signals to an optical element affect the coupling of the waveguide device to an optical fiber. A number of systems and methods are disclosed to adjust the coupling of the waveguide device to the optical fiber. These include dithering the tunable optical element at different frequencies along differing axes and using a lock-in technique to derive an error signal for each degree of motion, using a beamsplitter to form a secondary image of the focused beam on a position-sensitive detector, the use of a chiseled fiber to generate reflections from the angled facets, using an additional laser for a secondary image, or obtaining a secondary image from an angled fiber or a parasitic reflection.

Abstract: A fast method of switching optical signals using micro-mirror structures and control. The method selects an optical path for a micro-mirror device, the mirror device being coupled to a torsion bar device. The micro-mirror device is moved or pivoted about a torsion bar device, the micro-mirror device being operated about the torsion bar device through an operating range. The micro-mirror device is subjected to a mechanical force from the torsion bar and being subjected an electro-static force applied to the micro-mirror device. The method positions the micro-mirror device to a selected switching location within the operating range a selected region within a predetermined time. The micro-mirror device is controlled during a portion of time during the moving by receiving position signals periodically at a predetermined frequency from a sensing device coupled to the micro-mirror device.

Abstract: A thermo-optical device may use a heater to tune an optical device such as an optical switch, a Mach-Zehnder interferometer, or a variable optical attenuator, to mention a few examples. In some embodiments, polarization-dependent losses caused by the heating and power efficiency may be improved by defining a clad core including an optical core and cladding material on a substrate and covering the clad core on three sides with a heater.

Abstract: An optical waveguide element having a cladding layer formed on a substrate and at least one waveguide core formed in the cladding layer for transmitting an optical signal. Two heater sections are provided for shifting a phase of optical signals. The two heater sections show different design. This helps controlling heater induced birefringence.

Abstract: An electrically tunable coupler device is disposed on a substrate comprising a first and a second waveguide, for guiding optical signals. The coupler device comprises a heater element disposed adjacent the first waveguide for thermo-optically shifting the phase of the optical signal in the first waveguide in response to a control voltage applied to the heater element. The heater element is disposed in an interaction region of the optical signals, such that, within the interaction region, a temperature gradient across the first and the second waveguide is generated in dependence on the applied control voltage. A heat sink element can be disposed adjacent the second waveguide to absorb thermal energy from the heater element. This device can be fabricated at reduced cost and in increased packing density and is usable e.g. in directional couplers, Mach-Zehnder interferometers, optical ring resonators, IIR filters, or optical modulators.

Abstract: A technique for electrically mounting a surface-normal optical device or material on a waveguide-type optical device while the characteristics of the mounted device are effectively used is disclosed. The waveguide-type optical device comprises a substrate on which optical waveguides or fibers are provided and a trench is formed; a pair of electrodes which is assigned to each optical waveguide or fiber and is formed from the surface of the substrate to wall surfaces of the trench; and a material or device which is filled or inserted into the trench, and which has an electro-optic effect, thermo-optic effect, light emitting function, light receiving function, or light modulating function. Another type of device comprises a thin and surface-normal active optical device driven by an applied voltage, which is substantially vertically inserted into the trench and is fixed in the trench; and a support member attached to the inserted device.

Abstract: The present invention is an improved electro-optical device comprising a substrate-supported layer of electro-optical material disposed between upper and lower electrodes. Conventional practice has been to make the electrodes thick to minimize electrical loss. Applicants, in contrast, have discovered that the performance of the device can be improved by making the electrodes thin—typically about 2 microns or less and preferably about 0.5 micron or less. While the thin electrodes take a relatively large loss penalty at low frequencies, at higher frequencies the thin electrodes provide a relatively low loss, thus producing a flattened frequency response as compared with thick electrode devices. The device can maintain a wide operating bandwidth at frequencies of interest for optical transmission while reducing the required drive voltage.

Abstract: An object of the invention is to provide an electrode system for optical modulation of an optical modulator to reduce a thickness “E” of an electrode required for velocity matching and for reducing a propagation loss in the electrode. A substrate 2 is made of an electrooptic material and has one and the other main faces 2a, 2b opposing each other. An electrode system 20A is provided on the substrate 2 for applying a voltage for modulating light propagating in optical waveguides 6A and 6B. The electrode system 20A includes ground electrodes 3A, 3B and a signal electrode 4. A ratio “W/G” of a width “W” of the signal electrode 4 to a gap “G” between the ground and signal electrodes is 0.8 or higher. Preferably, the substrate 2 has a thickness “T” of 20 &mgr;m or larger, in a region where the optical waveguides 6A and 6B are provided.

Abstract: The invention provides a waveguide type liquid crystal optical switch that includes first and second cores so as to form a space therebetween, in which an optical path is switched between the first and second cores; a third core provided apart from the first and second cores, into which nematic liquid crystal orientated by an orientation film along a predetermined direction is filled, the third core overlapping to the space formed between the first and second cores; a first electrode arranged on an opposite side of the first and second cores with respect to the third core so as to overlap to the space between the first and second cores, second and third electrodes arranged on both sides of the first electrode, for orienting liquid crystal molecules along a direction perpendicular to the orientation direction of the orientation film; and a cladding for incorporating the cores and the electrodes.

Abstract: Molecular systems are provided for electric field activated switches, such as optical switches. The molecular system has an electric field induced band gap change that occurs via one of the following mechanisms: (1) molecular conformation change; (2) change of extended conjugation via chemical bonding change to change the band gap; or (3) molecular folding or stretching. Nanometer-scale reversible optical switches are thus provided that can be assembled easily to make a variety of optical devices, including optical displays.