Abstract: A multimode interference coupler having a tunable power splitting ratio and a method of tuning the splitting ratio. The tuning of the power splitting ratio is achieved by varying an effective refractive index around a portion in a multimode interference section.

Abstract: A method and apparatus for image sharpening in confocal microscopy or endoscopy observation, the method comprising: collecting true confocal return light from an observational field of an object; focussing the true confocal return light into a core of a fiber wave-guide; collecting near confocal return light from a volume partially overlapping the observational field; focussing the near confocal return light so as to be transmitted principally in a cladding of the fiber wave-guide; separately detecting the true confocal return light and the near confocal return light to produce a true confocal output signal and a near confocal output signal; and adjusting the true confocal output signal on the basis of the near confocal output signal to substantially eliminate from the true confocal output signal a component due to the near confocal output signal; whereby the effective volume of the observational field is reduced and the resolution is effectively increased.

Abstract: A termination arrangement for fiber optic cables includes a precision ceramic guide press fit into a sleeve on both the socket and pin termini. The precision ceramic guide of the socket terminus is extended through a bushing and alignment sleeve, and a compression spring is positioned between the bushing and a stepped washer secured in the connector so that the bushing, sleeve, and precision ceramic guide may all be moved relative to the stepped washer upon insertion of the ceramic guide of the pin terminus into the alignment sleeve. The length of each terminus is chosen so that any grommet on an environmentally sealed connector will always fall on a portion of the body which has the same diameter for each terminus so that one grommet can be used with a variety of different size cables. A rear section of both the pin and socket terminus bodies are stepped down to provide an area for the strength member of the fiber optic cable to be terminated to.

Abstract: The present invention relates to an optical fiber including a glass fiber and a primary coating encapsulating and in contact with the glass fiber, the primary coating being the cured product of a polyrnerizable composition which includes a monomer with a pendant hydroxyl functional group which can bond with a surface of the optical fiber and is present in an amount effective to promote adhesion. The present invention also relates to methods of making such optical fibers.

Abstract: An optical fiber Mach Zehnder Interferometer includes a first and second elongate optical fiber having a core and a cladding, first and second couplers wherein the cladding of the first optical fiber is coupled to the cladding of the second optical fiber. The first optical fiber includes a first elongate interfering arm where the first optical fiber extends between the first and second couplers. The first interfering arm includes a miniature bend formed therein. The second optical fiber includes a second elongate interfering arm extending between the first and second couplers and may also include a miniature bend formed therein. The miniature bends are contemplated to be either packed or unpackaged. The fibers may exhibit different coefficients of thermal expansion to maintain the path length differences of the interfering arms.

Abstract: A method of preparing an object with a radially-varying property is disclosed which includes the steps of providing a preform reactor including an outer container having a bottom, an inner container installed in the outer container, the inner container having a bottom, a rotating rod installed at a position in the outer container, and a sealing member for sealing the outer and inner containers at the bottoms thereof; filling the inner container with an inner material and a space between the inner container and the outer container with an outer material wherein the outer material has a different property from the inner material; removing the inner container; and rotating the rotating rod for laminar mixing of the inner and outer materials. An apparatus for carrying out the inventive method, and objects formed in accordance with the inventive method, are also disclosed.

Abstract: An LD module having a spot-size conversion LD for emitting a beam of a small aperture angle, an optical fiber or a waveguide and a lens for converging the LD beam to the fiber or the waveguide.

Abstract: The invention relates to a method and a modulator circuit for modulating light in a modulator circuit. The modulator circuit comprises a Mach-Zehnder modulator having at least one optical input and at least one optical output, said Mach-Zehnder modulator modulating light, which is fed to the input of the Mach-Zehnder modulator in response to applied electrical modulation signals from a driver circuit. According to a method of the invention, the applied modulation signal on the electrodes of the Mach-Zehnder modulator is superimposed by a pilot tone which is thus superimposed by the modulated light emitted by the Mach-Zehnder modulator. In response to the emitted modulated light, an electrical feedback circuit generates bias control signals for the bias circuit and driver control signals for the driver circuit for regulating the bias signal and the driver signal fed to the Mach-Zehnder modulator.

Abstract: An engager for creating an optical fiber link between a first optical signal carrier secured to a first connector and a second optical signal carrier secured to a second connector, and including a frame structure, a fiber ram block, and a shaft. The fiber ram block has a surface for connection to the second connector. The shaft is rotatably secured to the frame structure. The shaft has a first section of thread for threaded engagement with a second section of thread on a fiber backing member to which the first connector is secured. The shaft has a shoulder which contacts the fiber ram block so that, upon rotation of the first section of thread relative to the second section of thread, the shoulder moves the fiber ram block so that the fiber ram block moves the second connector into engagement with the connector.

Abstract: In accordance with the invention, an optical router for an optical communications system comprises a pair of transmissive Echelle gratings having their grating surfaces coupled by a waveguide grating. The arrangement provides for substantial design freedom in that the dispersive parameters include the shapes of the first and second Echelle gratings as well as the path length difference among the waveguides. Moreover the device eliminates any need for reflective surfaces in the Echelle gratings.

Abstract: An optoelectronic device includes two optical subassemblies mounted on an edge of a substrate. Electronic circuitry is mounted on the substrate. The two optical packages are electrically connected to the electrical circuitry. An optical coupling element is attached to one of the optical packages and another optical coupling element is attached to the other optical package. A rib is attached to the substrate and to one of the optical coupling elements so as to provide support for the optical coupling element, and another rib is attached to the substrate and to the other optical coupling element. Each optical coupling element has a respective ferrule receiving bore. The ferrule receiving bores are parallel to one another. A connection pin header is electrically connected to the electronic circuitry on the substrate. The connection pin header includes connection pins.

Abstract: An optical switch (10) includes an aligning member (12) with an aperture (28) extending between opposite sides to define an aligning groove (32). A first output waveguide (16) is in the aligning groove. An input waveguide (14) and a second output waveguide (18) are in a further groove (50) in the aligning member. The second output waveguide can move between two positions where optical signals from the input waveguide are respectively directed into the first and second output waveguides. In a variation, an aligning member (102) includes a plurality of the optical switches arranged to form a 1×N switching fabric (100). Further, two such switching fabrics (212, 213) can be coupled to define an M×N switching fabric (210).

Abstract: The invention is directed to optical devices comprising a solid-state structured glass substrate having at least one waveguide incorporated therein, particularly waveguides and lasers incorporating such structure. The invention is also directed to methods for modifying such devices and their properties. The waveguides and lasers of the invention provide advantageous high power and increased slope efficiency and find use, for example, in telecommunications applications.

Abstract: A system for writing fiber gratings has a plurality of writing stations, each writing station including a fiber mounting fixture for receiving an optical fiber to be exposed to a beam from a laser. The system includes a data capture module for capturing data generated from the exposure of optical fibers in each of the writing stations, and a steering assembly for directing the laser beam to each of the plurality of writing stations in turn.

Abstract: A package for optical components and a method for making the package are disclosed. The package comprises a quasi-planar substrate having a positioning floor, a platform and an optional ring frame of precisely determined height. Optical components picked and placed on a substrate floor, a raised platform and frame. A flexure assembly allows fine positioning of components requiring critical optical alignment.

Abstract: The disclosed technique enables fully integrated monolithic hybrid optoelectronic chips to be built that combine electronic circuits, optical devices that are either flip-chip bonded or surface mounted on the VLSI circuits, and fibers. Disclosed is a technique for attaching a fiber optic pigtail to connect a silicon photodetector and a CMOS receiver (or a phototransmitter and a driver) to create a fully integrated CMOS receiver circuit for multimode fiber applications, such as those at a wavelength of about 850 nm. The integrated silicon detector/CMOS receiver can serve as a cheap power/signal monitor (for low speed applications) or even a high-speed Gigabit/s detector.

Abstract: This invention relates to an optical transmission line having a structure that reduces dispersion with respect to signal light in a 1.55-&mgr;m band. Each transmission unit includes a dispersion-shifted optical fiber as a transmission medium and a mode removing unit for reducing the optical power of high-order modes excluding a fundamental mode of light signals propagating through the dispersion-shifted optical fiber. The dispersion-shifted optical fiber has an incident terminal on which the light signals are incident and an exit terminal from which the light signals are emitted, and has a cutoff wavelength longer than the wavelength of the light signals at a fiber length of 2 m. The mode removing unit has a structure for reducing the optical power of high-order modes to 1/10 or less, preferably 1/40 or less, of the optical power of the fundamental mode so as to satisfy the single-mode condition in relation to fiber length.

Abstract: A switch with an open state and a closed state suitably includes a cantilever having first and second states corresponding to the open and closed states of the switch, respectively. The switch may also include a magnet configured to provide an electromagnetic field that maintains said cantilever in one of the first and second states. Various embodiments may also include an electrode or electrical conductor configured to provide an electric potential or electromagnetic pulse, as appropriate, to switch the cantilever between the first and second states. Various embodiments may be formulated with micromachining technologies, and may be formed on a substrate.

Abstract: Miniature planar IR waveguides of thickness 30-50 &mgr;m, consisting of 12-mm long, 2-mm wide strips of Ge supported on ZnS substrates and tapered quasi-tapered waveguides, tapered from a thickness of 1 mm at the ends to a minimum of 1-100 &mgr;m at the center, are disclosed. The surface sensitivity is increased as a function of incidence or bevel angle. The tapered waveguide improves the efficiency of the optical coupling both into the waveguide from an FTIR spectrometer, and out of the waveguide onto a small-area IR detector. The tapering makes it possible to dispense with using an IR microscope couple light through the waveguide, enabling efficient coupling with a detector directly coupled to an immersion lens. This optical arrangement makes such thin supported waveguides more useful as sensors, because they can be made quite long (e.g. 50 mm) and mounted horizontally.

Abstract: An acoustic impedance-matching transformer includes a tapered acoustic energy transmission (metal) block, having an acoustic impedance less than that of a piezo-electric transducer in a metric direction toward that of the acoustic propagation medium of the waveguide, and by an amount that allows tailoring of the relative spatial dimensions of mating surfaces of the transducer and the block, so as to provide efficient broadband coupling of acoustic energy. The surface area of the end face of the block engaging the transducer is a corresponding fraction of the area of the transducer. The tapered block focuses acoustic energy toward the input aperture of the waveguide channel. The taper is determined in accordance with difference between the acoustic impedance of the aluminum block and that of a second acoustic wave propagation element, such as a quarter-wave section of plexiglass, interposed between the waveguide channel and the tapered block.