Abstract: The present invention relates to an optical fiber transmission line comprising a structure for making it possible to maintain a desirable mean transmission characteristic as a whole regardless of the fluctuation in total length caused upon cutting end portions; and an optical cable including the same. The optical fiber transmission line according to the present invention comprises a main transmission line and first and second end sections connected, respectively, to both ends of the main transmission line. As a typical configuration, the main transmission line is constituted by a single-mode optical fiber and a dispersion-compensating optical fiber. At a wavelength of 1.55 &mgr;m, the single-mode optical fiber has a positive chromatic dispersion, and the dispersion-compensating optical fiber has a negative chromatic dispersion.

Abstract: A plurality of glass or metal wires are precisely etched to form the desired shape of the individual channels of the final polycapillary optic. This shape is created by carefully controlling the withdrawal speed of a group of wires from an etchant bath. The etched wires undergo a subsequent operation to create an extremely smooth surface. This surface is coated with a layer of material which is selected to maximize the reflectivity of the radiation being used. This reflective surface may be a single layer of material, or a multilayer coating for optimizing the reflectivity in a narrower wavelength interval. The collection of individual wires is assembled into a close-packed multi-wire bundle, and the wires are bonded together in a manner which preserves the close-pack configuration, irrespective of the local wire diameter. The initial wires are then removed by either a chemical etching procedure or mechanical force.

Abstract: In an optical connector for securing an optical fiber by inserting it into an optical fiber positioning hole of a connector ferrule body, an end face of the optical fiber is disposed within the optical fiber positioning hole, a predetermined length region of the optical fiber on the end face side is in a free state adapted to expand and contract, and the end face of the optical fiber is buried in a refractive index matching material filling near an opening portion of the optical fiber positioning hole.

Abstract: A fiber optic connector assembly includes a ferrule terminated to at least one optical fiber. A pusher member is spaced behind the ferrule. A spring is provided for biasing the ferrule forwardly. The spring is fixed to the pusher member to provide a self-contained subassembly comprising the spring and pusher member.

Abstract: A planar lightguide circuit (PLC) phase shifter is fabricated on a chip which exhibits reduced thermal crosstalk by reducing the thermal resistance between the waveguide cores and the thermal “ground” (e.g., a heat sink) compared to the thermal resistance between the waveguide cores. This is accomplished by removing some of the glass from the backside of the chip over a small area under the phase shifters, depositing metal on the backside, and soldering it to a copper block heat sink.

Abstract: Unbalanced Mach-Zehnder interferometers (MZI) are useful for a number of applications including wavelength filters, gain flattening or gain equalization elements, and band splitters or combiners. A MZI is comprised of two couplers surrounding a phase shifting region, which consists of two arms with differential propagation constants. We disclose a means of using light exposure to unbalance a symmetric MZI consisting of substantially the same lengths of substantially the same fiber. In particular, the index of refraction of a fiber can be increased by exposure to ultraviolet light, and the magnitude of the change can be increased by using higher germanium doping or by hydrogen loading the fiber. The magnitude of the phase shift can be controlled accurately by varying the fiber length exposed, the light exposure intensity, the light exposure time, and the hydrogen loading or fiber composition.

Abstract: This invention is predicated upon applicants' discovery that UV-induced gratings can be formed through polymer coatings that include conjugated double bonds and aromatic moieties. Coatings with low concentrations of aromatic-containing free-radical photoinitiators provide both reasonable curing speeds and sufficient transparency that gratings can be written through them. Moreover some of these aromatic-containing free-radical photoinitiators act synergistically with non-aromatic ketone photoinitiators. Advantageous aromatic-containing free-radical photoinitiator concentrations are in the range 0.01%-0.1% and preferably in the range 0.02% to 0.05%. Advantageous polymer coatings are acrylate-based coatings.

Abstract: A bimetal-based temperature stabilized multi-FBG package with tunable mechanism mainly includes a moving pin, a bimetal fixture, a rotation sleeve, a locking pin. The moving pin has a first predetermined outer screw pitch at one end and an elongated slot at the other end for receiving the locking pin. The bimetal fixture has a main frame and a plate secured to the main frame. The main frame of the bimetal fixture has a tube member extending outwardly from the side wall thereof, and the tube member has a second predetermined outer screw pitch at the distal end thereof. The rotation sleeve has a first predetermined inner thread corresponding to the first predetermined outer screw pitch of the moving pin and a second predetermined inner thread corresponding to the second predetermined outer screw pitch of the bimetal fixture. The grating fiber is first placed inside the moving pin and then the fiber is metallized or soldered to the moving pin and the holding arm of the bimetal fixture.

Abstract: A device comprising a tapered glass structure produced from glass capillary tube by pulling technologies to generate an optimized geometry for high transmission efficiency of electromagnetic radiation. The device being bent near the tip to produce a cantilevered structure suitable for normal force sensing in a variety of attractive, repulsive and non-contact imaging modes.

Abstract: An array of micromachined mirrors are arranged on a first substrate at the intersections of input and output optical paths and oriented at approximately forty-five degrees to the paths. An array of split-electrodes are arranged on a second substrate above the respective mirrors. Each split electrode includes a first electrode configured to apply an electrostatic force that rotates the mirror approximately ninety degrees into one of the input optical paths to deflect the optical signal along one of the output optical paths, and a second electrode configured to apply an electrostatic force that maintains the mirror position. Stability may be improved by using the first and second electrodes in combination to first actuate the mirror and then balance the forces on the mirror to maintain its position. Reproducibly accurate positioning of the mirrors requires either the use of active positioning control or of mechanical stops.

Abstract: The present invention provides a dense wavelength division multiplexer for separating an optical signal into optical channels which minimizes channel leakage. The multiplexer includes at least one channel separator optically coupled to the inputting mechanism, and at least one dense optical channel comb filter optically coupled to the channel separator. In one embodiment, the dense optical channel comb filter includes: a lens optically coupled to the channel separator disposed at a distance equal to the focal length of the lens, a first birefringent wedge optically coupled to the lens at a side opposite to the channel separator, a second birefringent wedge optically coupled to the first birefringent wedge at a side opposite to the lens, and a non-linear interferometer optically coupled to the second birefringent wedge at a side opposite to the first birefringent wedge.

Abstract: An optical system includes a coupling for transmitting light between one single fiber light guide and multiple single fiber light guides. The interface surfaces coupling the single fiber light guide to the multiple light guides have polygonal cross-sectional shapes, and the interface surface of the single fiber light guide is substantially covered by the interface surfaces of the multiple single fiber light guides. The single fiber light guide on one side of the coupling and the multiple single fiber light guides on the opposite side of the coupling each have a smoothly tapered contracting section extending away from the respective interface surfaces.

Abstract: An optical-interconnect arrangement is disclosed in various embodiments. In one embodiment, an optical-interconnect node includes a an optical-link section and a processor-link section. The optical-link section includes an optical combiner and an optical splitter. The combiner combines an optical signal of a local node with optical signals from other connected nodes, and the combined signals are carried on a common waveguide. Each node has an optical splitter that splits the optical signals for local processing. The processor-link section includes a demultiplexer and a transmitter. The optical signals from a splitter are input to a demultiplexer, which separates and converts the optical signals to respective electrical signals. The transmitter converts a local electrical signal to an optical signal having a wavelength associated with the node.

Abstract: Inline optical circulators utilizing birefringent displacers to split an incoming beam into two orthogonally polarized beams and thereafter to recombine the beams. The birefringent displacers are used in combination with non reciprocal devices (Faraday rotators), reflectors and waveplates and serve to route a signal serially to the next port. Specific embodiments utilize birefringent wedges which provide circulators with reduced component counts and simplified alignment of the components. Circulators which do not utilize waveplates, and thus are relatively wavelength insensitive, are also described.

Abstract: A polarization-mode-dispersion emulator in accordance with the principles of the present invention includes a plurality of PMD-generating stages aligned in cascade so as to form a clear light-path through the stage concatenation. Each PMD-generating stage includes an optical birefringent crystal or crystals for the purpose of imparting differential group delay and a polarization-rotating plate such as a half-wave waveplate for the purpose of imparting state-of-polarization rotation from one PMD-generating stage to the next. The polarization-rotating plates are mounted to rotation apparatuses and a controller coordinates the relative rotation of each waveplate for the purpose of generating PMD in a controlled manner.

Abstract: A ridge waveguide-type optical semiconductor device and a method of fabricating the same. The method of fabrication includes forming a first clad layer, a core layer, a second clad layer and a contact layer, in the stated order on a semiconductor substrate, forming a strip-shaped etching mask on the contact layer, removing the contact layer and the second clad layer selectively by etching, using the etching mask, until the core layer is exposed, so as to form a ridge including etched second clad layer, and forming a semiconductor layer by crystal growth, so as to form a mode control layer on the exposed surface of the core layer. The semiconductor device includes a semiconductor substrate, a first clad layer formed on the substrate, a core layer serving as a waveguide, on the first clad layer, and a strip-shaped second clad layer on the core layer. A mode control layer is formed on the core layer, and insulating layers are formed on the mode control layer, at opposite sides of the second clad layer.

Abstract: An integrated optic device includes at least one waveguide formed in a surfaced thereof. The waveguide is formed utilizing a two-step proton exchange process in which the substrate is bathed in a strong acid and then subjected to a plurality of annealing cycles.

Abstract: The invention is an optoelectronic device including an optical subassembly enclosed within a plastic housing. The housing includes a wall with an aperture and a lens mounted therein. A plastic receptacle is mounted to the wall. The receptacle includes an opening which is aligned with the lens and which is capable of receiving an optical fiber so that the fiber is aligned with light emitted from the optical assembly. The receptacle is preferably mounted to the wall by means of epoxy.

Abstract: A method and apparatus for servicing or upgrading on demand, an optical fiber communication system from a single communication channel at one frequency such as a telephone circuit to two communication channel systems at two different frequencies such as telephone and TV signals.

Abstract: Apparatus for combining an RF signal at one frequency band and carried by a selected nominal wavelength of light with a RF signal at a different and separate frequency band and carried by another source of light having the selected nominal wavelength onto a signal optical fiber.