American Research Corporation of Virginia

Moog Gmbh

Other

Moog Components Group Inc.

American Research Corporation

K Peter Lo

Howard P Groger

Russell J Churchill

Norris E Lewis

Martin J Oosterhuis

Shufang Luo

Heath E Kouns

Martin Weiss

Myron T Coolbaugh

William F Sullivan

John W Raymonda

Lawrence H Decker

Roger L Reynolds

James M Sloan

Shu-Fang Luo

Howard J Moses

Nicholas V Nechitailo

The present invention relates generally to optical rotary joints () for enabling optical communication between a rotor and a stator, and to improved optical reflector assemblies for use in such optical rotary joints.

Optical reflector assemblies for use optical rotary joints

The present invention relates generally to optical rotary joints () for enabling optical communication between a rotor and a stator, and to improved methods of mounting such optical rotary joints on supporting structures such that the rotor and stator remain properly aligned.

Optical rotary joints, methods of mounting same in a properly-aligned manner, and optical reflector assemblies for use therein

The present invention provides improved collimating lens assemblies () which include: a singlemode fiber () terminating in a distal end; a step-index multimode fiber () having a proximal end abutting to the singlemode fiber distal end, and having a distal end; a graded-index multimode fiber () having a proximal end abutting the step-index multimode fiber distal end, and having a distal end; and a collimating lens () longitudinally spaced from the graded-index multimode fiber distal end by an intermediate air gap (), and operatively arranged to collimate light rays emanating from the graded-index multimode fiber distal end. The improved collimating lens assembly is characterized by the fact that there is no epoxy, silicone gel or index-matching material between the graded-index multimode fiber distal end and the collimating lens.

High-power collimating lens assemblies, and methods of reducing the optical power density in collimating lens assemblies

The present invention relates generally to optical rotary joints () for enabling optical communication between a rotor and a stator, improved methods of mounting such optical rotary joints on supporting structures such that the rotor and stator remain properly aligned, and to improved optical reflector assemblies for use in such optical rotary joints. The improved optical rotary joint enables optical communication between a rotor and a stator, said rotor having a longitudinal axis, and comprises: at least one optical source () mounted on one of said rotor and stator for transmitting an optical signal in a radial direction with respect to the longitudinal axis; at least one first reflector () mounted on the other of said rotor and stator for reflecting the optical signal transmitted from the source, said first reflector comprising a concave first reflective surface (), a line (L) in a plane taken through said first reflective surface being configured as a portion of an ellipse having first and second focal points (F, F), the first focal point being positioned substantially coincident with said rotor axis; a second reflector () having a second reflective surface () configured as a portion of a cone and positioned at the second focal point of the elliptical surface for receiving light reflected from said first reflective surface and for reflecting light in a different direction as a function of the apex angle of the second reflective surface; and a receiver () arranged to receive light reflected by the second reflective surface.

A fiber optic rotary joint and an associated reflector assembly are provided for supporting optical communications between a rotor and a stator. The fiber optic rotary joint includes at least one optical source carried by the rotor or the stator for transmitting optical signals. The fiber optic rotary joint also includes a reflector mounted upon the other one of the rotor and stator for reflecting the optical signals. Further, the fiber optic rotary joint includes a receiver for receiving the optical signals following their reflection. The reflector is generally shaped and positioned such that the path length along which the optical signals propagate from the optical source(s) to the receiver is equal, regardless of the rotational position of the rotor to the stator. The reflector may have a reflective surface shaped to define a portion of an ellipse and/or a reflective surface shaped to define a portion of a hyperbola.

Fiber optic rotary joint and associated reflector assembly

A highly-sensitive, rapid response fluorescent probe is based on the affinity of a polymer matrix for an analyte of interest. The probe includes a polymer matrix and a dye immobilized in the matrix. The polymer matrix has an affinity for an analyte of interest and the dye has little or no sensitivity to the analyte of interest when excited by an excitation source in a free state but has significant sensitivity to the analyte of interest when excited by the excitation source when immobilized in the matrix. Sensors incorporating the polymer/fluorophore probes of the present invention have the sensitivity and rapid response needed for detection of chemical agent and biological materials. Sensors using the probes provide sensitivity to Sarin at several hundred parts per trillion in one second or less. That is a notable advance over state-of-the-art detectors that require preconcentration steps, which in turn restrict response times to one minute or more. A wide-range of near-infrared excitable fluorophores are used as sensitive probes for analytes not detectable when the fluorophores are outside the polymer matrix. The present sensors provide early warning of the presence of toxic chemicals, provides for on-line analysis of trace materials in chemical and biological processing operations and biomedical processing operations, and provides for effective biomedical and environmental monitoring.

Fluorescent probes based on the affinity of a polymer matrix for an analyte of interest

An instrument for total internal reflection fluorescence spectroscopy having modular probe that inexpensively monitors vapors and liquid-phase analytes under field conditions is described. The system is particularly helpful in evaluating multiple analytes using the fluorescence of a material immobilized in a thin sorbent polymer coating. At the same time, the system is capable of monitoring trace quantities of analyte using a fluorescence-read immunological reaction. The device includes a diode laser source, a shaped optical element (which may be as simple as a microscope slide), and one or more amplified photodiode detectors. The shaped optical element propagates light from the diode laser in a series of internally reflective bounces.

Modular probe for total internal reflection fluorescence spectroscopy

The present sensor allows the user of any diode laser structure to be employed to provide sensitive chemical and biological detector. A diode laser electrochemical sensor is described in U.S. Pat. No. 5,591,407 &ldquo;Laser Diode Sensor&rdquo;. The present invention surpasses the capabilities of those sensors by measuring changes in the output power, output spectral characteristics or output signal auto-correlation function to detect the presence of chemical or biological films within the sensitive region.

Diode laser electrochemical sensor for detecting chemical and biological analytes

An optical fiber fluorescence sensor system capable of compensating fiber bending loss is provided. The system uses a modulated light-emitting diode and digital-signal processing chips to enhance the measurement of fluorescence signals. A fiber-optic oxygen sensor system suitable for measuring oxygen levels in gas and in aqueous media is provided. The system alleviates fiber bending loss. Detection of the signal-to-noise ratio of the system which exceeds 30 dB is done by using inexpensive components.

Loss compensation using digital-signal processing in fiber-optic fluorescence sensors

Optical chemical probes have layers of anionic and cationic polyelectrolytes and one or more dyes incorporated into these layers. The probes are placed into the medium and the dye or dyes react in the presence of the corresponding chemical. Color changes may be observed manually or by a photo detector. A light source may be employed to increase the optical signal received from the probe. Further, a waveguide may be used to trap multiple optical signals. The invention is used for chemical analysis.

Optical chemical sensor based on multilayer self-assembled thin film

The vibration and electrical characterization of a piezoelectric tactor actuator is described. The actuator is a rectangular laminated flat plate with two opposite sides simply supported and two others free. Under an axial compression from the supports, the plate deforms into a stressed shallow shell. Electrical high frequency harmonic signals within relatively low-frequency bursts are applied to the piezoelectric layers. Depending on the axial compression and pre-deflection, frequency and magnitude of electrical input, the tunable actuator exhibits frequency/mode-controlled high-force over large area vibrations with intense displacement jumps. A single-degree-of-freedom model and simplified 1-D models are provided. The tactor provides efficient conversion of electrical energy into mechanical.

Piezoceramic vibrotactile transducer based on pre-compressed arch

A-compact, diode laser-based sensor has applications in biological and chemical analysis. Unlike existing optical waveguide-based sensors, no external coupling to external optical fibers or waveguides is required to perform optical chemical, immunological or nucleic acid-based assay or to detect the presence of toxic or otherwise important chemicals. The sensor includes a surface-sensitive diode laser having a substrate layer, an n-contact layer positioned on a bottom surface of the substrate, an n-clad layer overlying the top surface of the substrate, a first guide layer overlying the n-clad layer, a quantum well layer overlying the first guide layer, a second guide layer overlying the first quantum well layer, a p-clad layer overlying the second guided layer and a p-doped cap layer overlying the p-clad layer. A pair of electrodes separated by a surface-sensitive region is positioned on the cap layer. The surface active region includes an oxide layer grown on the thick cap layer and an absorbing or non-absorbing film deposited on the oxide layer. For internal reflection, inorganic material coatings are applied to end facets or Bragg reflectors are etched in the cap layer. Detectors are positioned proximate the diode laser for detecting changes in film thickness or refractive index, absorption or other optical properties resulting from film deposition, surface reactions such as immunological or ion-exchange reactions, or other detectable processes.

Diode laser-based chemical and biological sensor

An apparatus and its accompanying method measures fluorescence decay, fluorescence amplitude and fluorescence polarization. The instrument includes a light emitting diode or laser diode light source, an amplified photodiode detector, and electronics and software for calculating the phase of the fluorescence from the computed inner product of the scattering and fluorescence signals. The electronics for measuring fluorescence decay includes two signal synthesizers, two downconverters, a simultaneously sampling analog-to-digital converter and means for calculating the inner product of the downconverted waveforms. A signal source, preferably a direct digital synthesizer, is used in combination with a digital-to-analog converter to provide a controllable output signal. That signal drives a modulatable light source, which is a light emitting diode, a laser diode or a combination of the two. Excitation light from the light source excites the sample fluorophore which is immobilized in a solid material. Fluorescence is detected using an amplified photodiode. The received signal is downconverted using a pair of mixers. The downconverted signals are digitized and stored. Preferably, the signals are digitized using a two-channel synchronous analog-to-digital converter controlled by a digital signal processor. Data from each channel are multiplied and summed to provide the inner product.

Fluorescence decay measurement by calculation of inner product

Fluorescence measuring methods and apparatus use planar optical waveguides to excite fluorescence in the evanescent field of the waveguides and photodetectors to sense the fluorescence produced. Chemically sensitive fluorophores are bound to the evanescent regions of the planar optical waveguides. Substrates support the waveguides. Photodetectors, positioned in the substrates with fields of view normal to the waveguides, detect the fluorescence. Wavelength-selective material coating surfaces of the photodetectors allow fluorescence to be detected while restricting entry of light at the excitation wavelengths. The photodetectors have high aspect ratios for detection of fluorescence generated by the optical waveguides. Preferably, the photodetectors are closely coupled to the fluorescence generated in the evanescent field of the waveguide. In alternative embodiments, lightguides near the waveguides direct fluorescence from the plane of the waveguides for transmission by integrated optical fibers to remote sensors. For chemical detection and analysis, energy is introduced to an edge of the waveguide. The edges are coated to reflect the energizing energy throughout the waveguide. The energy excites the chemically sensitive fluorophore film positioned on the waveguide. Inexpensive photodetectors without expensive photo-multipliers are mounted in substrates beneath the waveguides or at ends of lightguides extending from the substrates for detecting fluorescence.

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Blacksburg, VA, United States of America

K Peter Lo