Abstract: An optical device for rerouting and modifying an optical signal that uses a double pass through a liquid crystal modulator is disclosed. The optical device includes a first polarizer for providing polarized light, a liquid crystal modulator for selectively modifying the polarized light, a second polarizer for analyzing the light passed through the liquid crystal modulator, and a reflector for reflecting the analyzed light back through the second polarizer, the liquid crystal modulator, and the first polarizer. This arrangement provides a double pass through the liquid crystal modulator, thus significantly improving the attainable extinction ratio.

Abstract: Techniques for optically sampling the output of a Mach-Zehnder electro-optic modulator without interfering the output optical signal.

Abstract: An apparatus for effecting conversion between communication signals in a first signal-form and in a second signal-form includes: (a) a first circuit region arranged on a monocrystalline silicon substrate; (b) an amorphous oxide material overlying the first circuit region; (c) a monocrystalline perovskite oxide material overlying the amorphous oxide; (d) a second circuit region arranged a monocrystalline compound semiconductor material overlying the perovskite oxide; (e) a receiver established in the first circuit region for converting received input signals in the first signal-form into converted signals in the second signal-form provided at a transfer locus; and (f) a signal processor established in the second circuit region coupled with the transfer locus for processing received converted signals to present a formatted signal in the second signal-form at an output locus. The apparatus is implemented in a monolithic integrated structure arranged on a single monolithic silicon substrate.

Abstract: A dispersion compensation system includes a number of etalons cascaded in series to form a chain. The chain of etalons introduces a cumulative group delay that compensates for chomatic dispersion and dispersion slope. At least one of the etalons is tunable, thus allowing the system to be turned, for example to compensate for different amounts of dispersion and/or manufacturing variations.

Abstract: An optical device includes at least one kind of and a plurality of optical circuits optically connected in series wherein the optical circuits are arranged in a spiral on a common substrate.

Abstract: An optical phase modulator includes a bandpass multilayer stack, formed by a plurality of dielectric layers, preferably of GaAs and AlAs, and having a transmission function related to the refractive index of the layers of the stack, for receiving an optical input signal to be phase modulated. A phase modulator device produces a nonmechanical change in the refractive index of each layer of the stack by, e.g., the injection of free carrier, to provide shifting of the transmission function so as to produce phase modulation of the optical input signal and to thereby produce a phase modulated output signal.

Abstract: A piezoelectric-optic switch and method of fabrication therefor is provided. The switch includes a Mach-Zehnder interferometer having a pair of waveguides disposed in a planar substrate, and strips of piezoelectric material such as PZT disposed on a top surface of the substrate over each of the waveguides. The PZT material is electrophoretically deposited on the substrate to a thickness of between 10 and 20 microns and sintered, resulting in a high density on the order of 8 gm/cm3. The PZT strips deform the planar substrate surrounding the waveguides to an extent necessary to adjust the phase between optical signals transmitted through the waveguides, which in turn allows an optical coupler connected to the output of the waveguides to effect a signal cross-over.

Abstract: The present invention makes light input/output portions being a coupling portion with an optical fiber and a Y-branch using a rib waveguide, and a bending portion using a channel waveguide, wherein the rib waveguide and the channel waveguide is connected by a tapered waveguide. So that the present invention can improve the crosstalk, loss and operating voltage characteristics.

Abstract: A hollow waveguide based optical switch, and novel hollow waveguide-based switch architectures for optical communications. The switch comprises a pair of hollow waveguides overlapping over a common section that includes a common opening, a first conductive flexible lever attached to one of the hollow waveguides, the first lever configured to assume upon actuation at least two switching positions within the pair of waveguides at the common opening, a second conductive flexible lever attached to the other of the hollow waveguides, the second lever configured to assume upon same the actuation same at least two switching positions within the pair of waveguides as the first lever while keeping a substantially parallel geometry with the first lever, and means to actuate the first and the second levers in order to achieve the at least two switching positions.

Abstract: A hybrid integration process for fabrication of an optical cross-connect switching apparatus. The switching element is based on the deflection of light beam in electro-optic materials by applying electric field across electrodes of an appropriate configuration. The integration process includes fabrication of a substrate (e.g. silicon substrate) with 2D imaging optics from polymeric materials (or silica), fabrication of the light deflecting element, and assembly of the deflecting element on the substrate with imaging optics. The fabrication of the light deflecting element includes fabrication of a LN (lithium niobate) block. The LN block assembled in an optical switching apparatus includes a two-dimensional waveguide formed on a surface of the LN block and an electrode on a surface of the LN block.

Abstract: A wavelength agile optical transponder system and method for testing a fiber optic link formed of a single fiber. An optical source coupled to the optic link provides a signal at a first wavelength which is propagated towards a wavelength division multiplex (WDM) coupler disposed on the optic link. Upon receiving the optical signal by a receiver, an optical cross-connect arrangement is utilized for transmitting the optical signal after translating its wavelength into a second wavelength. By evaluating the optical signal in the optical loop-back thus effectuated, the path integrity of the optic link is determined without having to know the wavelength of the incident signal or direction of transmission.

Abstract: Using grating built-in type optical fiber coupler and an optical amplifier, multiplex separation of the specific wavelength efficient is done without using an optical circulator etc., and the function to add the signal of specific wavelength efficiently can be realized. In addition, it is in offering the wavelength multiplex transmission system that obtains a device cheaply.

Abstract: Laser wavelength stabilization is achieved by locating a low selectivity reference filter in a reference path of a laser beam. The low selectivity reference filter, with a periodicity greater than the control filter, is used together with a lookup table for the reference filter to resolve the uncertainty associated with the multivalued control filter. After the wavelength uncertainty for the control filter is resolved, the laser beam is stabilized based on the response of the control filter, as if the reference filter was not present.

Abstract: An optical fiber communication system according to the present invention has, for example, first and second phase conjugators. The first phase conjugator converts a signal beam from a first optical fiber into a first phase conjugate beam. The first phase conjugate beam is supplied to the second phase conjugator by a second optical fiber. The second phase conjugator converts the first phase conjugate beam into a second phase conjugate beam. The second phase conjugate beam is transmitted by a third optical fiber. The second optical fiber is composed of a first portion located between the first phase conjugator and a system midpoint and a second portion located between the system midpoint and the second phase conjugator. The total dispersion of the first optical fiber substantially coincides with the total dispersion of the first portion, and the total dispersion of the second portion substantially coincides with the total dispersion of the third optical fiber.

Abstract: It is an objective of the invention to reduce the technical complexity involved in the implementation of optical filters used in particular for the encoding and decoding of OCDM signals. It is also intended to simplify the tuning in order, on the one hand, to make the selection of the required transmission channels as simple as possible and, on the other, to be able at the receiving end to regulate the optical filter drift at the transmitting end for optimum reception. This object is achieved by an optical filter arrangement containing a first optical filter and a second optical filter connected in series or in parallel and with the second optical filter having an FSR adjustment range differing from the FSR adjustment range of the first filter. An advantageous effect is that the second optical filter facilitates fine tuning, with in particular the readjustment at the receiving end of optical filter drifts at the transmitting end being simplified.

Abstract: A 3D coupling system includes a layered structure that receives an input of a defined mode size. The layered structure includes a plurality of layers with varying indexes, and outputs a vertically mode converted beam associated with the input beam. A planar lens structure receives the vertically mode converted beam, and performs lateral mode conversion on the vertically mode converted beam. The 3D coupling structure outputs a laterally and vertically mode converted beam. A high index-contrast waveguide structure receives the laterally and vertically mode converted beam, and provides the laterally and vertically mode converted beam to a receiving device with less than 1 dB loss.

Abstract: In an optical system in which light output from an optical fiber (11) is collimated into parallel light rays by a gradient index rod lens (13), reflected by a filter (4) and then converged again by the rod lens (13) so that the resulting light is coupled to an optical fiber (12), a principal beam component of the light output from the optical fiber (11) disagrees with an optical axis (32) of the optical fiber (12) to thereby cause a coupling loss.

Abstract: An arrayed waveguide grating type optical multiplexer/demultiplexer in which the 1 dB band width is large, the ripple is small, and the degradation of the adjacent crosstalk can be controlled. A waveguide forming portion is formed on a substrate. The waveguide forming portion includes an optical input waveguides, a first slab waveguide, an arrayed waveguide including a plurality of channel waveguides arranged side by side and which have different lengths with the differences preset, a second slab waveguide, and a plurality of optical output waveguides arranged side by side, all of the components being connected in the order stated. A single mode straight waveguide narrower than the optical input waveguides is provided at the output end of at least one or more optical input waveguides. A multi-mode trapezoidal waveguide whose width increases toward the arrayed waveguide is provided at the output end of the straight waveguide.

Abstract: The invention writes a fiber Bragg grating (FBG) onto a fiber. The invention uses a phase mask to separate an input beam into two beams, and possibly encode each of the two beams with phase information. The invention then uses one or more modulators to possibly encode phase information onto the two beams. An image relay telescope collects the two beams and causes the two beams to interfere with each other to form the FBG on the fiber according to the phase information encoded on the two beams. The image that is incident onto the input surface of the telescope is re-imaged at the output surface of the telescope. Thus, either the phase mask or the modulators, or a combination of both can encode phase information onto the two beams.

Abstract: A bandpass filter for a predetermined wavelength range is comprised of a pair of uniform fiber gratings each having a cutoff characteristic with a sharp inclination for prohibiting transmission of light in a longer wavelength range and a shorter wavelength range adjacent to the predetermined wavelength range, and a pair of chirped fiber gratings each having a wide cutoff band characteristic for prohibiting transmission of the light in a longer wavelength range and a shorter wavelength range adjacent to the predetermined wavelength range. The uniform fiber gratings and chirped fiber gratings are formed on the same light propagation path. A dielectric multilayer filter or an arrayed-waveguide grating is integrally incorporated to realize a fiber-based optical component which has a wavelength transmission characteristic suitable for use in a WDM system.

Abstract: The present invention relates to a chromatic dispersion compensator comprising a Bragg grating with quadratically varying pitch, said Bragg grating having a group time response with a quadratic component Q1 and a linear component L1, and the compensator further comprising a Bragg grating with linearly varying pitch, said Bragg grating with linearly varying pitch having a group time response with a linear component L2, and said linear components L1 and L2 being opposite in sign.

Abstract: A method and system for determining strain impressed on an optical fiber at a possibly indeterminate temperature. The fiber (14) is formed with at least two sensors having different strain and temperature characteristics, preferably a Bragg Fabry-Perot sensor having a Fabry-Perot cavity (16) formed between two like Bragg gratings (10, 12) and another Bragg grating 18 of a different pitch written into the Fabry-Perot cavity. Many such pairs can be written if the Bragg gratings reflect in different bands. The fiber is irradiated with broadband light, and the reflection is spectrally separated to produce separate spectra for all sensors. Wavelength shifts from two types of sensors can be correlated with strain and temperature according to predetermined variations of the shifts with known strain and temperature changes.

Abstract: The present invention relates to the field of optical fiber telecommunications. More specifically, the subject of the invention is a slanted Bragg grating optical fiber and a process for manufacturing such a fiber. The slanted Bragg grating optical fiber of longitudinal axis Z has slanted Bragg gratings photowritten in said fiber and having refractive index modulations along said axis Z, inclined at a same writing angle with respect to a normal plane to said axis Z and defining planes called writing planes forming the same angle than the writing angle with said normal plane, each writing plane forming with others writing planes specific angles called angles of rotation about said axis Z.

Abstract: An optical filter, including a Bragg grating, is compression tuned such that when under one compressional load (or no load) the grating has a first profile and under a second compressional load the grating has a second profile. One application is to allow the grating filter function to be parked optically between channels of a WDM or DWDM optical system.

Abstract: A tunable optical structure and devices based thereon for the compensation of chromatic dispersion in a multi-channel light signal are provided. The optical structure includes a waveguide and a Bragg grating provided therein. The Bragg grating has a plurality of grating components, each associated with one or a few of the channels to be compensated. The period of each grating component is selected to allow compensation of chromatic dispersion experienced by this particular channel or these particular channels, thereby taking into account the wavelength-dependent dispersion slope of the light signal. Tuning means are also provided in order to adjust the dispersion of the grating components to the required values.

Abstract: A thermally diffused dual-core (TDDC) waveguide is provided that has a pair of spaced cores 12,14 disposed within a cladding 16. The waveguide 10 is formed of a glass material having the appropriate dopants to allow light 15 to propagate in either direction along the cores 12,14. The TDDC waveguide is formed by heating a portion 22 of the dual-core waveguide 10 to symmetrically diffuse the dopants of the cores 12,14 into the cladding 16. Consequently, the optical mode fields of the cores spread beyond the optical mode field of each original core such that the optical field in one core 12 excites the optical field in the adjacent core 14 to optically couple the two cores 12,14. The amount of diffusion of the core into the cladding is dependent on the temperature of the heat and the time the heat is applied to the dual-core waveguide. The cores may be diffused so that the cores overlap to thereby create a unitary core. The TDDC waveguide may be used to provide a coupler or wavelocker device.

Abstract: Embodiments of the invention include an optical fiber device such as a modulator, variable attenuator or tunable filter including an optical fiber having a core region, a cladding layer around the core region, and a controllable active material disposed in, e.g., capillaries or rings formed the cladding layer. The active materials include, e.g., electro-optic material, magneto-optic material, photorefractive material, thermo-optic material and/or materials such as laser dyes that provide tunable gain or loss. The application of, e.g., temperature, light or an electric or magnetic field varies optical properties of the active material, which, in turn, varies or affects the propagation properties of optical signals in the device. The optical device includes a tapered region that causes the core mode to spread into the cladding region and, simultaneously, allows the active material to be relatively close to the propagated modes, thus allowing interaction between the active material and the propagating modes.

Abstract: A coupling structure is disclosed. An optical device includes a core layer for guiding a light beam exiting a core layer of an optical fiber. The core layer of the optical device avoids a power loss of a light beam and establishes an adiabatic coupling. The core layer of the optical device may have a tapered surface.

Abstract: An on-chip silicon-based optical coupler used to guide light from an optical fiber to a waveguide. The incoming wave is confined vertically by stacks of graded index materials. In the lateral direction, a linear taper formed by etched holes or trenches confines the wave.

Abstract: An optical module has

Abstract: An air blown fiber tube cable having improved thermal stability in contrast to conventional air blown fiber (ABF) tube cables and within which one or more air blown optical fiber units can be installed. The air blown fiber tube is formed from a cross-linked polyolefin (preferably cross-linked high density polyethylene) comprising at least one non-polymer filler material having a coefficient of thermal expansion less than the coefficient of thermal expansion of said tube.

Abstract: High quality epitaxial layers of monocrystalline materials can be grown overlying monocrystalline substrates such as large silicon wafers by forming a compliant substrate for growing the monocrystalline layers. An accommodating buffer layer comprises a layer of monocrystalline oxide spaced apart from a silicon wafer by an amorphous interface layer of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. The accommodating buffer layer is lattice matched to both the underlying silicon wafer and the overlying monocrystalline material layer. Any lattice mismatch between the accommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer. In addition, formation of a compliant substrate may include utilizing surfactant enhanced epitaxy, epitaxial growth of single crystal silicon onto single crystal oxide, and epitaxial growth of Zint1 phase materials.

Abstract: An optical signal delay mechanism having a cladding material and a signal conducting core embedded for protection in the cladding material. The core has a longitudinal direction which is the direction of propagation of the optical signal and a transverse direction which is a direction substantially perpendicular to the direction of propagation of the optical signal. The embedding of the core is such that longitudinally spaced apart core sections are transversely separated by a continuous region of cladding material. This provides a more compact, robust and cheaper alternative to known delay mechanisms.

Abstract: An optical waveguide fiber amplifier comprising a core region comprises at least in part between 1300 wt.ppm and 3600 wt.ppm Er2O3, between 6.0 wt. % to 10.0 wt. % Al2O3 and between 9.0 wt. % and 20.0 wt. % GeO2. The amplifier also comprising an inner clad surrounding the core region and an outer clad surrounding the inner clad. The relative refractive index percentages and radii of the core region, inner clad and outer clad are chosen from the following ranges: the relative refractive index percent of the core segment within the range of from about 0.5% to about 2.0%; the relative refractive index percent of the inner clad within the range of from about 0.0% to about 0.4%; the outer radius of the core region within the range of from about 0.7 &mgr;m to about 1.5 &mgr;m; and, the outer radius of the inner clad within the range of from about 4.3 &mgr;m to about 18.8 &mgr;m.

Abstract: The present invention relates to an amplification optical fiber comprising a structure which can yield a higher amplification gain, and a fiber optic amplifier including the same. The fiber optic amplifier comprises, at least, an amplification optical fiber for amplifying signals having wavelengths different from each other, and a pumping light source for supplying pumping light for signal amplification. The amplification optical fiber has one end for inputting pumping light and has a cutoff wavelength shorter than the signal wavelength but longer than the pumping light wavelength.

Abstract: A method of using a beam of ultra-short laser pulses, having pulse durations below 10 picoseconds, to adjust an optical characteristic within an optical medium is provided. The beams would have an intensity above a threshold for altering the index of refraction of a portion of the optical medium. The beams could be selectively applied to the optical medium and any structures formed or existing therein. Thus, the beam could be moved within a waveguide in the optical medium to alter the index of refraction of the waveguide forming any number of different longitudinal index of refraction profiles. The beam could also be moved within the optical medium near the waveguide to alter an effective index of refraction of a signal traveling within the waveguide. The techniques described can be used to improve, alter or correct performance of waveguide-based optical devices, such as arrayed waveguide gratings and cascaded planar waveguide interferometers.

Abstract: Systems and methods are described for communications networks. A method, includes deploying a communication link, at least a portion of which is protected against active equipment failure, that includes a splitter-combiner communicatively coupled between a data drop/add device and a headend. The systems and methods provide advantages because a communication network can be protected, at least in-part, against active equipment (e.g., data drop/add device) failure, passive equipment (e.g., optical fiber) failure, and/or equipped for non-intrusive expansion of the network.

Abstract: Structures include a substrate with a release layer on the surface of the substrate and a uniform material over the release layer. The release layer generally includes powders or partly sintered powders. In some embodiments the uniform material is an optical material, which can be a glass. The optical material can be mechanically decoupled fro the substrate such that the optical material is stress free. The release layer can function as a transfer layer for transferring the uniform material to another substrate of separating the uniform material to create a freestanding structure. The release layer can be formed by the deposition of a material with a higher sintering temperature than powders used to form the uniform material. In other embodiments, a heating step is performed to preserve the release layer while consolidating powders on top into the uniform material.

Abstract: A planar optical waveguide is provided. The waveguide includes a substrate having a top surface, a first end, an opposing second end, and a first channel extending from the first end toward the second end along the top surface. The first channel has a first sidewall extending toward the second end, a second sidewall extending toward the second end, and an endwall engaging the first sidewall and the second sidewall. A cladding layer is disposed on the top surface of the substrate. A core is disposed within the cladding layer. The core has a first end generally co-planar with the endwall and a second end. A method of manufacturing the waveguide and connecting the waveguide to an optical fiber is also provided.

Abstract: An information processing apparatus is disclosed which includes: a retrieving element for retrieving storage medium information and image data information from a memory formed integrally with a storage medium having image data recorded thereon; a recording element for recording to a database the image data information in conjunction with the storage medium information, the image data information having been retrieved by the retrieving element; and a displaying element for displaying the storage medium information and the image data information recorded by the recording element.

Abstract: In a case where a first operation section selects between a video signal in a first scheme and a video signal in a second scheme, a second operation section selects between video signals including the video signal of the scheme selected at the first operation section and those of lower-order schemes than the selected scheme and outputs the selected video signal, when there are video signals of lower-order schemes than the scheme selected at the first operation section.

Abstract: A method for generating a verification code. The method comprises providing a digital video disc having data stored thereon configured to cause a digital video disc player to read the data in a manner sufficient to cause a video presentation to be displayed and to randomly generate a verification code from a plurality of alternative codes. The method further comprises operating the digital video disc player in a manner to cause the video presentation to be displayed, operating the digital video disc player in a manner such that after at least part of the video presentation is displayed the digital video disc player generates the verification code via the data of the digital video disc, and using a client computer system to input the verification code via the Internet to a host computer system.

Abstract: A reserved program record setting method and apparatus for a program preview of a broadcasting program to be recorded and used with a video cassette recorder (VCR) and a television set. The method includes a first step of judging whether a program preview of a broadcasting program to be reserved and recorded is being broadcast, a second step of storing a program reserving code of the broadcasting program when the program preview is currently being broadcast in the reserved program recording mode, and a third step of completing a reserved program recording operation by turning off the VCR, thereby quickly reserving a record for a predetermined program by once pressing a program preview storing key while the program preview of the broadcasting program to be recorded is being broadcast.

Abstract: Navigation information can be generated from compressed and packetized MPEG streams, and the navigation information then placed in a separate navigation file that can be accessed to permit navigation functions to be performed during decompression and playback of the MPEG stream. An authoring tool may be used to parse the MPEG stream and generate the navigation data. The navigation data may then be used to select individual start points, different audio channels, special effects, etc., during playback.

Abstract: A method of recording and reproducing video data is provided. The method of recording video data in an information storage medium includes the steps of (a) decoding originally encoded video data, (b) re-encoding the decoded video data in a different way to the originally encoded video data, (c) generating video transform information which is to be referred to for decoding the video data into its original state, and (d) recording the generated video transform information and tho re encoded video date in the information storage medium. Accordingly, the video data can be properly reproduced even if it is re-encoded in a different way to the originally encoded video data.

Abstract: Methods and apparatus for switching between a live video decoding and a recorded playback in a digital video and recording system. A received video data stream is transmitted to a first-in first-out video decoder buffer without first looping the video data stream through a playback buffer. The video data stream is transmitted from the video decoder buffer to a video decoder. If a “pause” command is received, the video data stream is transmitted to a first-in first-out playback buffer, while continuing to transmit the video data stream to the video decoder buffer. Transmission of the video data stream to the video decoder buffer is halted when the video decoder buffer fills up. The last byte of the video data stream that was transmitted to the video decoder buffer is marked. If a “play” command is received, the video data stored in the video decoder buffer is transmitted to the video decoder.

Abstract: There is provided an apparatus provided with an image blur prevention function, including: a blur correction driving means for performing correction of image blur; an actuator separate from the blur correction driving means, consuming energy of the actuator changing depending on time; a power supply for supplying energy to the blur correction driving means and the actuator; and a variable circuit for changing an energy supply pattern in supplying energy to the blur correction driving means by the power supply before or after consuming energy of the actuator changes.

Abstract: In a digital camera having a half mirror retractable out of the optical path and an optical viewfinder receiving light reflected from the half mirror, the sensitivity of an image-sensing device is set as specified by the user. When a relatively high sensitivity is specified, an image to be recorded is shot with the half mirror operated as a quick-return mirror, and, when a relatively low sensitivity is specified, an image to be recorded is shot with the half mirror kept in the optical path. A sensitivity that cannot be coped with simply by changing the position of the half mirror is set by adjusting, in conjunction therewith, the output gain of the image-sensing device.

Abstract: A system operates on a computing resource that is accessible to a plurality of clients via a communication network. A storage service of the system operates on the computing resource and is configured to store unrendered image data corresponding to scenes. The unrendered image data may be, for example, raw image data or scene colorimetric data. A rendering service of the system also operates on the computing resource and is configured to process the unrendered image data to generate rendered images. In particular, the rendering service processes the unrendered image data responsive to requests from the clients communicated over the communication network, and the rendering processing is based on rendering parameters determined in accordance with the client requests. In addition, a printing service may be provided to transform the rendered images into a tangible form, in accordance with printing requests from the clients.

Abstract: A processor for processing photosensitive material has a rotatable outer drum and an inner sprocket wheel which is independently rotatable from the outer drum. Two sets of sprocket teeth and, are provided on the sprocket wheel to engage with the material to be processed and to positively drive the material into and out of the processor.