Abstract: A method and apparatus for monitoring a structure and for locating the position of an event including a light source, a waveguide, and a detector means. The waveguide receives light from the light source so that the light is caused to propagate in counter-propagating optical signals in the waveguide. The waveguide includes the counter-propagating optical signals or some characteristic of the signals modified or effected by an external parameter caused by or indicative of the event to provide modified counter-propagating optical signals. The detector means detects the modified counter-propagating optical signals effected by the parameter and determines the time delay or difference between the modified counter-propagating optical signals in order to determine the location of the event.

Abstract: An optical isolator includes a first optical collimator, an isolated core, a second optical collimator and an outer tube. The first and second collimators and the isolated core are accommodated in the outer tube. The second collimator has a long sleeve which entirely accommodates the isolated core. The isolated core includes a first polarizer, a Faraday rotator crystal, and a second polarizer positioned in sequence within a toroidal magnetic core. An axial length of the toroidal magnetic core is equal to or slightly less than an overall length of the two polarizers and the rotator crystal. The two polarizers and the rotator crystal are sized such that an overall diameter of the isolated core is less than an inner diameter of the long sleeve. The magnetic core is glued within the long sleeve.

Abstract: According to one aspect of the present invention, a resin ferrule, for use in an optical fiber connector, is provided including: a capillary 1 having an axial part 2; and a flange 13 protruding from the axial part 2; the ferrule having an optical fiber insertion hole 3 axially passing through the capillary 1. The capillary 1 and the flange 13 are integrated into a monolithic structure with thermoplastic resin. The capillary 1 has a planar-shaped front end surface 11, and a front end part 10 extending towards the front end surface 11, in a convergent fashion where the front end part 10 has the outer diameter of the radial cross-section thereof reduced along the axial direction thereof towards the front end surface 11 with the cross-section kept concentric. According to another aspect of the present invention, a die is provided for molding a resin ferrule, for use in an optical fiber connector, as defined above.

Abstract: A method and apparatus for high power, broad gain, high efficiency, low noise, cladding pumped fiber amplifiers and lasers. The present invention utilizes a fiber taper in which the inner cladding decreases from a wide to narrow portion with the fiber core remaining the same diameter. The apparatus includes a light guiding section and a light source. The light guiding section has a cladding layer surrounding a fiber core with a fiber taper. The light source is arranged to couple pump light into the side of the cladding layer at the wide diameter portion. The pump light essentially propagates along the tapered portion towards the narrow diameter portion.

Abstract: The present invention provides an optical attenuator comprising an optical attenuator module, an optical splitter, a detector and a control unit. Input radiation (Pi) is received at the attenuator module which is operable to attenuate the input radiation to generate corresponding attenuated radiation (Po). The detector is operable to receive a portion of the attenuated radiation (0.1 Po) and generate a corresponding electrical signal T1. The signal T1 is applied by the control unit via a first feedback loop to regulate the attenuator module so that radiation power of the attenuated radiation is maintained to a predetermined level. In a situation where an interruption of the input radiation (Pi) occurs, the control unit is operable to monitor temperature of the attenuator module using a thermistor sensor and to regulate the temperature of the module using a second feedback loop to a predetermined temperature during the interruption.

Abstract: The present invention entails a phase mask for producing a plurality of volume gratings for use as optical couplers and method for creating the phase mask. The phase mask is produced by creating a plurality of volume gratings having predetermined characteristics which allow the phase mask, when excited by a coherent light wave, to produce a plurality of volume gratings in a recording material.

Abstract: An optical switching method and apparatus. In one aspect of the present invention, the disclosed apparatus includes first and second multi-mode interference (MMI) splitting devices in a semiconductor substrate. First and second outputs of the first MMI splitting device are optically coupled to first and second inputs, respectively, of the second MMI splitting device. First and second phase control devices are included in the semiconductor substrate. The first input of the second MMI splitting device is optically coupled to the first output of the first MMI splitting device through the first phase control device. The second input of the second MMI splitting device is optically coupled to the second output of the first MMI splitting device through the second phase control device. The first input of the first MMI splitting device is selectively optically coupled to the first and second outputs of the second MMI splitting device in response to the first and second phase control devices.

Abstract: An optical multiplexing/demultiplexing device has a structure wherein a curved waveguide for input, linear waveguides for output, and a planar waveguide are provided within a substrate. The curved waveguide is discontinuous, and the curved waveguide and planar waveguide are separated from each other with an equal interval interposed therebetween. A light signal that is input to the curved waveguide is reflected by discontinuous surfaces of the curved waveguide. Afterwards, the respective reflected light signals are distributed to corresponding linear waveguides through the planar waveguide for every wavelength and focused thereon. Further, the light signals of the respective wavelengths, which are input into the linear waveguides, are multiplexed by and focused on the discontinuous portions of the curved waveguide.

Abstract: A method for determining whether an imager assembly outside of a camera body meets predetermined focus specifications, wherein the imager assembly includes an image sensor and a camera mounting plate having reference features adapted to cooperate with alignment features in the camera body to locate the image sensor at a predetermined focal plane, including the steps of: mounting the imager assembly onto an imager mounting apparatus having equivalent alignment features; and utilizing low-coherence light interferometry to determine whether the image sensor will meet predetermined focus specifications when mounted in a camera body.

Abstract: A method for determining whether an imager assembly outside of a camera body meets predetermined focus specifications, wherein the imager assembly includes an image sensor and a camera mounting plate having reference features adapted to cooperate with alignment features in the camera body to locate the image sensor at a predetermined focal plane, including the steps of: mounting the imager assembly onto an imager mounting apparatus having equivalent alignment features; and utilizing low-coherence light interferometry to determine whether the image sensor will meet predetermined focus specifications when mounted in a camera body.

Abstract: A fiber optic cable tensioning and positioning apparatus includes a base, and a vertical support wall integrally connected to the base. A first support connects to a portion of the vertical support wall and supports a first portion of the fiber optic cable. A first clamp attaches to the first support for securing the first portion of the fiber optic cable to the first support. A second support connects to another portion of the vertical support wall and supports a second portion of the fiber optic cable. The second support is pivotally connected to the vertical support wall. A second clamp attaches to the second support for securing the second portion of the fiber optic cable to the second support. A knob also pivotally connects to the vertical support wall, and is connected to a cam.

Abstract: The high speed data link includes a light modulating device having an output, a source of light of a certain wavelength and a superconductive material, which is switchable between superconducting and non-superconducting states. This light modulating device also includes an arrangement for switching the superconductive material to provide at the output a train of light pulses having the certain wavelength. The high speed data link further includes a wavelength changing device, for changing the wavelength of the light pulses, an optical fiber, for directing the train of wavelength changed light pulses away from the wavelength changing device, and an arrangement, for receiving the train of wavelength changed light pulses. The receiving arrangement includes a demultiplexer, for dividing the train of wavelength changed light pulses into a series of sub-trains of wavelength changed light pulses, and a series of optical receivers, each optical receiver detecting at least one of the sub-trains.

Abstract: The present invention is a method for isolating faults in multi-stage photonic switch networks. Photonic switches in a photonic switch network are first verified individually, using self-test paths built into the photonic switch. Then, interconnecting optical fibers of the photonic switch network are checked. Each photonic switch is equipped with a transmitter and detector. During test, a photonic switch uses its transmitter to transmit light through an optical fiber interconnection to a second photonic switch. Pre-existing pathways within the photonic switches are used to access and route the light. When the second photonic switch detects the transmitted light, the optical fiber interconnection passes the continuity test. When the light cannot be detected, the optical fiber interconnection has a fault that must be repaired. By repeating this process for all optical fiber interconnections between all photonic switches, the photonic switch network can be checked for faults.

Abstract: A broadband wavelength-division multiplexer comprises two input waveguides for two input signals, each of which is from a different wavelength band, a multi-mode interference waveguide for producing an output wavelength-division multiplexed (WDM) signal comprising the two input signals where at least one of the two input signals is partially coupled to produce the output WDM signal, and an output waveguide for providing the output WDM signal. Optionally, at least another output waveguide can be used to trap all or some power not coupled to produce the output WDM signal.

Abstract: A mechanically-adjustable variable optical attenuator includes a beam attenuator shaped as a concave quasi-cone. The beam attenuator has a sharp tip and a base, and can be rotationally symmetric with respect to a central axis extending between the tip and the base. The beam attenuator is positioned with its central axis perpendicular to the direction of the light beam to be attenuated. The extent of the beam attenuator obstructing the light beam is varied by moving the beam attenuator into and out of the light beam. The inwardly-curving, quasi-cone shape of the beam attenuator allows achieving a high resolution while limiting the beam attenuator size.

Abstract: To form an optical element (20), in particular an interferometric sensor, an optical fiber (1) is placed tangent to a cylindrical supporting element (2); a straight portion (1a) of the optical fiber and the supporting element are surface fused; and a cavity (26) is formed in the optical fiber (1), the cavity being defined by facing surfaces (27,28) of the straight portion (1a) substantially perpendicular to the axis of the straight portion (1a). The optical fiber (1) and supporting element (2) may be subjected to traction during surface fusion, to form a small cross-section portion close to the cavity, and which, when light is conducted by the optical element, provides for reducing the amount of light dispersed in the cavity.

Abstract: A ferrule connection optical isolator with an optical fiber, wherein the optical isolator includes a ferrule with at least one processed end surface. The optical fiber consists of two kinds of materials and has a concentric level difference between the materials. A small cylindrical magnet having a size larger than the outer diameter of the level difference portion but smaller than the outermost diameter of the ferrule is connected to the level difference portion. A guide ring is inserted and fixed in the magnet, and an optical element that consists of at least one polarizer and at least one Faraday rotator is connected and fixed in the guide ring.

Abstract: A laser tracking interferometric length measuring instrument has a laser source and a tracking articulating optical lever provided on an optical path of an interferometric optical system. To track a retroreflector, the optical lever reflects a laser beam at the retroreflector, which reflects the beam back to the optical lever. This beam is reflected onto a quadrant photodiode. An attitude control means is used to control the attitude of the optical lever so that the laser beam reflected by the optical lever falls on the neutral point of the photodiode.

Abstract: A two-dimensional optical switch (10) includes a hermetically sealed housing (41) cooperable with several input fibers (11-18) and several output fibers (21-28). A digital micromirror device (71) is disposed within the housing, and can selectively effect travel of radiation between each input fiber and any one of the output fibers. The housing includes two lens sections (56, 57), which each have a platelike support portion (106), and several lens portions (111-118) of approximately semi-spherical shape that project from the inner side of the support portion. Each of the input fibers is fixedly secured to an outer side of one lens section in alignment with a respective lens portion thereon, and each of the output fibers is fixedly secured to the outside of the other lens section in alignment with a respective lens portion thereon.

Abstract: A fiber optic cable and method of manufacturing the same having at least one optical fiber component, at least one strength member and at least one ultra-low shrinking filament. The at least one ultra-low shrinking filament having a shrinkage of about 0.2% or less when heated and held at about 85° C. for about seven days. At least one strength member and at least one ultra-low shrinking filament being disposed generally between the at least one optical fiber component and a cable jacket. The jacket generally surrounding the at least one optical fiber component, the at least one strength member and the ultra-low shrinking filament. The cable can include an interfacial layer interposed between said at least one optical fiber component and the jacket. Additionally, the cable can be riser or plenum rated.