Abstract: In a digital optical switch, an input waveguide and two output waveguides form a Y-shaped splitter or switch. Electrodes are positioned on each output waveguide at the junction with the input waveguide. The electrodes extend as narrow strips across the waveguides. The inner edges of the electrodes are curved to form a smooth continuation profile to the signal paths to reduce losses.

Abstract: An optical fiber cable capable of absorbing water and resisting any undesirable increase of transmission loss caused by temperature variations. It has a core assembly formed by surrounding a stack of cores (1) in e.g. ribbon form by a shock absorbing member (2), at least one member (3) of high tensile strength and a sheath (4) formed from e.g. a thermoplastic resin and enclosing the core assembly and the high-tensile member (3). The shock absorbing member (2) is a strand of e.g. yarn not absorbing water, but carrying a water-absorbing resin.

Abstract: This invention provides a novel wavelength-separating-routing (WSR) apparatus that uses a diffraction grating to separate a multi-wavelength optical signal by wavelength into multiple spectral channels, which are then focused onto an array of corresponding channel micromirrors. The channel micromirrors are individually controllable and continuously pivotable to reflect the spectral channels into selected output ports. As such, the inventive WSR apparatus is capable of routing the spectral channels on a channel-by-channel basis and coupling any spectral channel into any one of the output ports. The WSR apparatus of the present invention may be further equipped with servo-control and spectral power-management capabilities, thereby maintaining the coupling efficiencies of the spectral channels into the output ports at desired values.

Abstract: A double-clad optical fiber includes a core, a multimode inner cladding layer disposed about the core, and a second cladding layer disposed about the inner cladding layer. The core includes an active material for absorbing pump radiation received by the inner cladding. The multimode inner cladding includes truncated regions including a first material, where the first material has an index of refraction that is different than the material of the inner cladding that surrounds said truncated regions, for promoting the scattering of pump radiation propagating in the multimode inner cladding for increasing the absorption of the pump radiation by the active material of the core. Particles can be distributed in soot deposited via Outside Vapor Deposition for forming the truncated regions in an optical fiber drawn from the preform.

Abstract: A photonic crystal waveguide apparatus has a photonic crystal having a waveguide which is capable of transmitting light having a frequency within a bandgap of the photonic crystal, and a resonant stub connected to the waveguide to control light in the waveguide. The resonant stub has a resonator region and a connecting channel which connects the resonator region to the waveguide. The resonant stub controls light transmission characteristics of the waveguide by creating a transmission zero in the transmission band of the waveguide. A tuner for tuning the resonant stub may also be provided to control the transmission zero to provide an active optical apparatus such as an on/off switch or a modulator.

Abstract: An integrated optical sensor using optical waveguide micro-cavity resonators. Using a laser and a detector it is possible to detect changes in the position of the resonance position, in wavelength or frequency, of one or more modes of the resonator. The change in resonance can be made dependent on chemicals, which have been adsorbed by chemically or biologically sensitive material provided in close proximity to the resonator.

Abstract: The frequency-selective optical multiplexer comprises, an LC polarization controller, a spectral demux/mux and input/output optics including two ports, a first optical path spatially separated from a second optical path and polarization-dispersive optics. The polarization dispersive optics are disposed between the ports and the optical paths; generate from an optical signal a pair of polarization components, composed of a first polarization component and a second polarization component having orthogonal polarizations; and output the first and second polarization components via the first and second optical paths, respectively. The first and second polarization components have first and second polarizations when the optical signal is received at one port, and have the second and the first polarizations, respectively, when the optical signal is received at the other port.

Abstract: A long period grating (8) by which an excitation light propagated through the 2nd core (4) of a double-core type optical fiber composed of the 2nd core (4) formed on the outer circumference of the 1st core (2) is guided into the 1st core (2) is formed on the 1st core (2) to improve an excitation efficiency.

Abstract: The optical fiber cable includes an assembly of at least two flexible tubes accommodating optical fibers, a sheath enveloping the assembly of tubes, and at least one filamentary form strength member at the periphery of the assembly of tubes. The tubes preferably extend in the sheath in a helical or an SZ assembly. The tubes are stuck together. The sheath is preferably made of polyethylene and the tubes are preferably made of polyvinyl chloride (PVC) or a thermoplastics elastomer with diol flexible segments. In this method, when extruding the sheath around the tubes, the temperature at which the material of the sheath is extruded is adjusted to cause the tubes to stick together.

Abstract: An optical switch constructed from first and second waveguides. The first and second waveguides have ends disposed across a gap such that light traversing the first waveguide enters the second waveguide when the gap is filled with a liquid having a first index of refraction, whereas light traversing the first waveguide is reflected by the gap when the gap is filled with a material having a second index of refraction that is substantially different from the first index of refraction. The gap is part of a trench that contains a liquid droplet made from a droplet material having the first index of refraction. The droplet is located in the trench and is movable between the first and second positions in the trench, the droplet filling the gap in the first position. The gap is filled with a material having the second index of refraction when the droplet is in the second position.

Abstract: Disclosed are an all-dielectric self-supporting optical cable and a manufacturing method thereof. The all-dielectric self-supporting (ADSS) optical cable installed on an extra-high voltage electrical power transmitting pylon comprises a first armor rod made of metal material and connected to a dead end of the all-dielectric self-supporting optical cable; and an insulating member for insulating the first armor rod.

Abstract: An FM signal converter comprising: an amplitude detecting unit for detecting amplitude variation of a plurality of signals that are multiplexed with subcarriers, as an amplitude variation signal; a peak detection unit for determining from said amplitude variation signal whether a peak of the amplitude of said plurality of signals exceeds a threshold and for generating peak detection information that includes information about said peak of the amplitude; a frequency signal source for providing signal with a predetermined frequency that differs from any of the frequencies of said subcarriers; an amplitude phase control unit for adjusting amplitude and phase of the signal from the frequency signal source according to said peak detecting information and outputting the adjusted signal as a corrected signal; signal combining means for combining said corrected signal and said plurality of signals multiplexed with subcarriers, with considering a time for generating the corrected signal; and an FM modulator for

Abstract: A multiple channel optical multiplexing/demultiplexing system utilizes a beam splitter to divide a single multi-wavelength beam of optical energy into two multi-wavelength beams, or to combine a plurality of multi-wavelength beams into a single output beam. In the demultiplexing configuration, a pair of demultiplexers are configured to receive and separate the two multi-wavelength beams into a plurality of wavelength channels. The two multi-wavelength beams are thus demultiplexed in parallel, allowing greater efficiency by avoiding excess beam attenuation. The individual demultiplexers can be incorporated into a single unitary device or can be optically interconnected as separate parts. Alternatively, the demultiplexing system can use multiple beam splitters to divide a single input multi-wavelength beam into a plurality of multi-wavelength beams for parallel demultiplexing in a plurality of demultiplexers.

Abstract: The present invention is a chromatic dispersion compensator. The chromatic dispersion compensator includes a first 3-port optical circulator, a first grating coupled to the second optical port of the first 3-port optical circulator. A polarization controller is coupled to the third optical port of the first 3-port optical circulator. The chromatic dispersion compensator further includes a second 3-port optical circulator, the polarization controller is coupled to the first optical port of the second 3-port optical circulator and a second grating is coupled to the second optical port of the second 3-port optical circulator.

Abstract: A variable optical attenuator is provided, and in one embodiment, a communication beam and associated alignment beam are generated by a beam generating element. The alignment beam may later be sampled by a sensor that can provide a relative location of the alignment beam with respect to the sensor. The communication beam may then be positioned so that a desired percentage of the communication beam enters an output fiber. Information, such as alignment beam offset, may be used to position the communication beam. In another embodiment, the variable optical attenuator may utilize one or more reflecting devices, such as a MEMS device, to provide optical beam attenuation. In this configuration, the MEMS device may position a focused communication beam in such a manner that a desired percentage of the communication beam enters an output fiber.

Abstract: A fiber optic cable having strength assemblies (30) adjacent a tube having at least one optical fiber therein, at least one of the strength assemblies including a strength member for imparting crush resistance to the cable. The strength member is generally coupled to a first jacket, and may be surrounded by a single jacket, or by an armor tape and a second jacket. The strength member may be disposed in a recess of the tube. When crush loads are applied to the fiber optic cable, the stresses created in the cable are advantageously distributed by strength assemblies (30) whereby stress concentrations and undue deflection of the cable in response to the crush loads are avoided. The arrangement of the cable components and strength assemblies (30) inhibits slippage and/or warping of the components under stress, and thereby evenly distributes the stress for preventing crush induced attenuation in the optical fibers.

Abstract: An opto-electrical printed circuit board (PCB) and compatible opto-electrical package. The PCB includes a base material, one or more optical fibers imbedded in or on top of the base material, and one or more transparent substrates imbedded in or on top of the base material covering the optical fibers. The optical fibers provide a high speed interconnect between two or more electronic devices attached to the PCB. The electronic devices interface to the optical fibers through the transparent substrate. The opto-electrical package includes a base material, an optical receiver and an optical transmitter attached to the bottom side of the base material, an encapsulating polymer that covers the optical receiver and optical transmitter, and one or more power and ground connection points attached to the bottom side of the base material.

Abstract: A bandwidth tunable fiber Bragg grating (FBG) device performs tuning in an optical transmission circuit by placing a grating in a compliant material, which is transversely loaded to create longitudinal strain through the Poisson effect of materials. Careful application of various load magnitudes along the length of the grating through the compliant material creates a strain gradient along the length of the grating, which chirps the grating thus resulting in altering the bandwidth of the grating. Tuning the grating bandwidth results, effectively, in tuning the dispersion of light being reflected off the grating. Insertion of such a device in the optical link allows for dynamic dispersion compensation in the link. The ability of the device to ‘dial-in’ a desired amount of dispersion is what makes it valuable.

Abstract: The percentage fraction of fundamental mode power located in the cladding holes of different holey fibers (PFholes) is shown as a function of wavelength in microns of the fundamental mode (&lgr;). Properties of two groups of holey fibers are shown. The upper group of three curves shows embodiments of the invention with &Lgr;=0.75 &mgr;m and d/&Lgr;=0.6, 0.7 & 0.8 respectively, where d is the hole diameter and &Lgr; the hole spacing or pitch. The lower group of curves, which are almost superimposed on each other, show properties of holey fibers representative of the prior art with &Lgr;=3.2 &mgr;m and d/&Lgr;=0.6, 0.7 & 0.8 respectively. A huge improvement in the mode power present in the holes is evident. In the prior art curves, the mode power fraction is generally less than 1%, whereas with the illustrated embodiments of the invention, holey fibers with 10-40% of the fundamental mode power in the holes are achieved.

Abstract: An improved dense wavelength division multiplexer for the separation of optical channels is provided. The dense wavelength division multiplexer includes the inputting of an optical signal with the optical signal containing a plurality of optical channels; the separating of one or more of the plurality of optical channels from the optical signal using separators at least partly arranged in a multi-stage parallel cascade configuration; and the outputting of the separated plurality of channels along a plurality of optical paths. The dense wavelength division multiplexer of the present invention provides for a lower insertion loss by requiring an optical signal to travel through fewer optical components in the separation process.