Abstract: An active semiconductor device that performs in a substantially polarization independent manner. A quantum well waveguide is intermixed by intermixing atoms across an interface between well and barrier layers. The atoms include at least 2 groups wherein intermixing of one group is at a substantially greater rate than another group. Cations are interdiffused at a greater rate than said anions across interfaces between well and barrier layers. The intermixing must be sufficient to provide strain within layers of the waveguide and sufficient to at least partially degenerate light hole and heavy hole bands of the structure. Preferably intermixing is sufficient to completely degenerate light hole and heavy hold bands to essentially produce a device that is completely polarization independent.

Abstract: In the design of transcutaneous energy transfer devices variation in spacing between the coils results in energy transfer efficiency changes. These changes may have other causes. It is proposed to use an autotuning circuit and a voltage control circuit in cooperation with feedback from the internal coil in order to better maintain energy transfer levels as desirable. The feedback is typically provided via IR communication; however, when skin is highly pigmented, IR communication is inefficient. A method and system for using RF signals to accomplish the communication is disclosed.

Abstract: A hybrid filter includes a dichroic interference WDM filter closely coupled with a Bragg grating. Preferably the Bragg grating is housed within a sleeve having an end face that is directly coupled with an end face lens of the WDM interference filter. The entire filter can be placed within a single housing and temperature controlled. Etalon effects are lessened by placing the Bragg grating as close as possible to the WDM filter. Multiple hybrid filters of this type optically coupled to an optical circulator provided multi-channel demultiplexing.

Abstract: A flow meter for use in scuba diving is disclosed. The device has a coil or, alternatively, two coils separated by a predetermined distance and sensors for measuring induced electromotive force. The device is provided with a switch to enable it to be activated. The switch also acts to disable the device and allow compass operation. An embodiment of the device including a compass and a processor allows for navigation functions to be performed.

Abstract: A device in accordance with the invention uses a novel combination of two four port optical circulators, Bragg optical fiber diffraction gratings and a single erbium-doped optical amplifier (EDFA) to implement at least dual wavelength bi-directional (single fiber) optical amplifier module. A system using an amplifier module in accordance with the invention, advantageously allows communication network managers to simultaneously reduce the cost of signal amplification hardware across a fiber optic network, increase fiber utilization, simplify field installation and maintenance operations, and maintain adherence to conventional protection philosophies such as "one system per fiber." Furthermore, the system is tolerant of unwanted effects from back reflections that may be present from a faulty optical connector or a fiber break at either end.

Abstract: A voltage controlled attenuator for an optical telecommunication system comprises an optical attenuator placed between an input and an output lens for obstructing the path of an incoming light beam. The attenuator has variable attenuation (reflection, absorption, etc.) which is controlled for maintaining a preset power of the outgoing light beam. To this end, a fraction of the outgoing signal is diverted to an output detector by reflecting off an end face of a lens, and processed for obtaining a control signal representative of the output power. The control signal actuates a dc motor which displaces the attenuator to a position corresponding to a preset output power.

Abstract: A method and device is provided wherein a reinforcement is provided for one or more optical fibers. One or more fibers are inserted into a sleeve made of a material that is substantially the same as the material of the cladding of the one or more optical fibers. The bore of the sleeve is sized to accommodate the one or more optical fibers; After the one or more optical fibers is inserted into the sleeve sufficient heat is applied to the sleeve for a duration to collapse the sleeve onto the one or more optical fibers. Preferably, the sleeve is a glass pre-form consisting substantially of 90% or greater silica.

Abstract: A method is disclosed for using a numerical method such as finite elements to adjust a model of an object for use with computer integrated manufacturing. The adjusted model is useful in correcting errors introduced in manufacturing. The method requires the model to be available in an electronic form. An object produced based on the model is measured to produce an electronic facsimile. The two electronic representations are then correlated and some differences between them are found. With one or more of the differences, a phenomenon that would have caused the difference(s) is determined and applied in an inverse manner to the model. A system for carrying out the invention is also disclosed.

Abstract: A novel design for producing bandpass filters with essentially square shapes with little or no ripple in the passband zone. Filters are of the all-dielectric type that consist of multiple cavities of bandpasses with the first and last cavities consisting of four less layers than the inner cavities. The inner cavities all have the same number of layers. All of the cavities are separated from each other by quarter wave thick layers of low index material. Layers of low index material may be added between the filter and the entrance and exit mediums. Multiple half-waves are added to the outer cavity quarter-wave stacks in particular and also may be added to some of the inner cavity stacks, These sharpen the transition from low transmission to high transmission without unduly adding ripple to the high transmission zone. The thickness of the first few layers and last few layers may be altered to enhance the transmission of the filter by matching the index structure of the passband to the adjacent mediums.

Abstract: A non-minutia method and apparatus for comparing a reference fingerprint image to a candidate fingerprint image are disclosed. During enrollment of a reference image, a unique reference set of data is generated in a reference coordinate system by placing a group of line segments on the reference image. A collection of constraints is used for defining the subspace for each line of the reference group. A similar set of candidate line segments is constructed on the candidate fingerprint image in a candidate coordinate system. A candidate set of data is determined and then compared with the reference set of data using translation and rotation of the coordinate systems. Tolerances of the comparison are also provided for.

Abstract: A device for connecting a first optical fiber end held by a first connector plug selectively to second or third optical fiber ends held by different types of connector plugs, in which each different type of plug has an associated connector socket, these sockets each including a non-circular connector flange and each having a ferrule alignment sleeve held by a retainer bushing projecting outwardly from the connector flange, the alignment sleeves being of the type suitable for receiving cylindrical ferrules attached to each fiber end. The device comprises a fixed part having an aperture extending between its inner and outer surfaces, and having a connector adapter projecting from the inner surface and suitable for receiving the first connector plug, and having a radially extending outer surface portion accessible from the outer surface and surrounding a recess suitable for receiving the retainer bushing of another connector plug.

Abstract: An optical method and apparatus is provided for determining the color and profile of a target surface of an object. The target surface is scanned with an incident beam of light containing a plurality of wavelengths including at least one well defined wavelength. A return beam reflected from the target is split into at a first and second return beam. The first return beam is utilized for detecting the profile of the target surface; and, a plurality of detectors are provided that detect color information corresponding to the target surface from the second return beam.

Abstract: A device for distributing an optical signal has an optical waveguide with a plurality of gratings disposed in series therein, the gratings having a predetermined reflectivity response within a specific wavelength range; an optical circulator having at least three ports, one of the ports serving as an input port for receiving the optical signal, and another port for removing at least a part of the optical signal reflected from one of the gratings; and control means for individually controlling at least some of the gratings to effect a change of the wavelength range of the reflectivity response of the gratings. The change may be a shift, an expansion or a compression of the range. The device can function as a signal distributor (router), an equalizer or a demultiplexer. The reflectivity response is preferably a sloped response.

Abstract: A system for automatically aligning optical components without active alignment techniques is provided. Optical components are placed into an alignment sleeve having an opening with a diameter sized to tightly receive optical components. Optical fibers having thermally expanded core ends are used to coupled light within the alignment sleeve. In instances where the optical fibers are offset from the longitudinal axis of the sleeve, means are provided to prevent rotation of an optical fiber tube holding the optical fibers.

Abstract: A method and apparatus is provided that lessens the unwanted effects of noise present at the input of an imaging system. By tapping a small portion of a laser input signal containing wavelengths of light corresponding to red, blue, and green of light used to scan the surface to be imaged, the tapped signal is used to generate three beams that correspond to the red, blue, and green content of the laser input signal. Signals generated at the output of the system that correspond to the color of the scanned surface are normalized with the signals that correspond to the three beams generated by the tapped signal. The normalized output signal indicative of the color of the surface is noise reduced; substantially most of any noise present at the input is eliminated from the output of the device.

Abstract: This invention discloses a mechanical stress measurement system which utilizes a birefringent coating and spectral demodulation to determine the magnitude and angular orientation of the stresses in a mechanical element from which the loads acting on that mechanical element are calculated. The invention provides for the measurement of Torque, Axial and Bending loads in a shaft, whether they exist singularly or in combination, without the requirement for electrical, mechanical or physical contact with the shaft, and is able to determine the magnitude and sense of the torque and axial loads, and the magnitude and plane of the bending load.

Abstract: An attenuator capable of controllably attenuating at least two wavelengths of light is configured to have an optical waveguide section having at least two Bragg gratings disposed therein in series. The Bragg gratings have a sloped reflectivity response within a predetermined wavelength range. The sloped response is a function of refractive index variations within each of the grating elements. By compressing or expanding at least one of the gratings, the periodicity is modified so as to shift its central wavelength within a predetermined wavelength range.

Abstract: A lensing system is provided for coupling light from one optical fiber to another through a plurality of graded index (GRIN) lenses. The system is capable of coupling light of two significantly different wavelengths in a relatively efficient manner. More specifically, a first GRIN lens having at least two ports on an outwardly facing end face is provided for coupling light of one of the wavelenghts from one of the at least two ports to another of the at least two ports. A second GRIN lens typically being about one half pitch, having an end face juxtaposed to an end face of the first GRIN lens, is provided for, in combination with the first lens, adjusting for differences in the two significantly different wavelengths, so that light will efficiently be coupled between a third graded index lens and the first graded index lens that are of different lengths to accommodate for the different wavelengths of light.

Abstract: The invention is concerned with apparatus for use in a fingerprint imaging system, of the type comprising a light source; a fingerprint testing station for producing and transmitting an image of a fingerprint reflected off a fingertip; a first lens positionable for receiving light from the fingerprint testing station and for producing an image of the fingerprint; aid a CCD camera positionable in a first optical path which includes the fingerprint testing station and the first lens and which is capable of converting the fingerprint image into an electrical signal. In accordance with the invention, the apparatus further includes a second lens capable of receiving miscellaneous images of objects viewable from the vicinity of the apparatus which are displaced from the fingerprint testing station, and mechanism for selectively providing a further optical path including the second lens and the CCD camera while interrupting the first optical path.

Abstract: A method and apparatus are provided of optically detecting transient motion from the surface of a workpiece. After directing a laser beam onto a surface of a workpiece the beam is reflected from it and then interferes with a pump beam removed from the laser source, inside a real-time holographic material, so as to form a grating diffracting the pump beam into a reference beam, which interferes at the output of the real-time holographic material with the received light beam, so as to produce a signal representative of the surface transient motion. An electric field is applied to the holographic material of sufficient magnitude to increase substantially the intensity of said reference beam and to give to this beam a phase differing substantially from the phase of said received light beam.