Abstract: Distributed fiber optic chemical and physical sensors provide a relatively highly uniform response over the length of the fiber by, for example, varying such properties as the core/cladding index of refraction ratio to compensate for the non-linearity in sensitivity due to the loss of higher order modes in multi-mode fibers. The variation of the ratio changes the absorption coefficient of the fiber and can be used to compensate for any non-linearity in response. Other techniques for compensation also are disclosed.

Abstract: The inner eye of a surgical patient is illuminated by incorporating an optical fiber in a ring configuration imbedded into or attached to a contact lens. The viewing surface of the lens if planar to optimize the surgeon's view. The opposite surface of the lens is curved to conform to the patient's eye. A solution conduit irrigates the eye. The apparatus is easily positioned and easily directed. The apparatus also is sufficiently inexpensive to be disposable.

Abstract: A sensor system comprises a broadband light source, a birefringent sensor, a detection circuit, and a signal processing unit. The preferred detection circuit further includes a variable frequency oscillator, a modulator, and a photodetector. The modulator modulates the output of the birefringent sensor with a modulation signal from the variable frequency oscillator. The modulation produces an interference signal having a variable interference frequency. By determining the frequency of the modulation signal from the variable frequency oscillator that minimizes the interference frequency, the detection system is able to determine the difference in frequency between first and second spectral components of the output of birefringent sensor. The detector may be constructed using entirely solid state optics/electronics. The preferred fiber grating sensor comprises a birefringent optical fiber having a cladding and a core.

Abstract: Distributed fiber optic chemical and physical sensors provide a relatively highly uniform response over the length of the fiber by, for example, varying such properties as the core/cladding index of refraction ratio to compensate for the non-linearity in sensitivity due to the loss of higher order modes in multi-mode fibers. The variation of the ratio changes the absorption coefficient of the fiber and can be used to compensate for any non-linearity in response. Other techniques for compensation also are disclosed.

Abstract: A sensor system comprises a broadband light source, a birefringent sensor, a detection circuit, and a signal processing unit. The preferred detection circuit further includes a variable frequency oscillator, a modulator, and a photodetector. The modulator modulates the output of the birefringent sensor with a modulation signal from the variable frequency oscillator. The modulation produces an interference signal having a variable interference frequency. By determining the frequency of the modulation signal from the variable frequency oscillator that minimizes the interference frequency, the detection system is able to determine the difference in frequency between first and second spectral components of the output of birefringent sensor. The detector may be constructed using entirely solid state optics/electronics. The preferred fiber grating sensor comprises a birefringent optical fiber having a cladding and a core.

Abstract: Systems and methods using a neural network based portable absorption spectrometer system for real-time automatic evaluation of tissue injury are described. An apparatus includes an electromagnetic signal generator; an optical fiber connected to the electromagnetic signal generator; a fiber optic probe connected to the optical fiber; a broad band spectrometer connected to the fiber optic probe; and a hybrid neural network connected to the broad band spectrometer. The hybrid neural network includes a principle component analyzer of broad band spectral data obtained from said broad band spectrometer.

Abstract: A method of determining the wavelength of light transmitted in an optical fiber comprises the steps of filtering the light using a filter, and then detecting the filtered light, and then determining the wavelength of the filtered light. The filter comprises a fiber grating which is recorded in a portion of the optical fiber. The fiber grating preferably has a modulated index of refraction with a modulation amplitude that varies from a first end to a second end of the fiber grating, and a modulation period defined by a grating constant that varies from the first end to the second end of the fiber grating. The fiber grating at least partially prevents transmission of light within a wavelength spectrum, and prevents transmission of a substantially larger portion of the light at a first end of the wavelength spectrum than at a second end of the wavelength spectrum. Therefore, the wavelength of the filtered light can be determined by determining a proportion of the light which was transmitted by the filter.

Abstract: Apparatus for analyzing biological samples includes a unique surface which promotes adhesion, growth and optical analysis of samples. The unique surface is formed at the bottom of each well of a microplate and provides increased surface area with a distribution of features operative also to shape and redirect light used to sense test results. The unique surface may be used in forms such as a monolith, a microplate, a chamber, a flask and others.

Abstract: A fiber optic sensor system comprises an optical fiber, a first reflector and a second reflector. The first reflector provides a fixed reference for measuring the optical path length between the second reflector and a reference reflector. The first and second reflectors respectively receive first and second portions of light emitted by the optical fiber and then reflect the light back to the optical fiber. The optical path length between the first and second reflectors varies in accordance with a sensed parameter. In operation, first and second interferograms are acquired that are produced by the interference of light reflected from the first and second reflectors with light reflected from a reference reflector. The first and second interferograms are then used to determine an optical path length between first and second reflectors. Finally, the optical path length between the first and second reflectors is used to determine the value of the sensed parameter.

Abstract: A low cost portable fiber optic fluorometer is packaged as a personal computer peripheral and is based on interchangeable modules. One embodiment of the fluorometer comprises an excitation source, a detector, a signal processor, frequency source, wavelength selector, and an optical interface. The optical interface is exclusively fiber optic-based, thereby simplifying optical alignment and reducing the cost of the fluorometer. In another embodiment, the excitation source is an inexpensive monochromatic excitation source. In this case, the monochromatic excitation source and the first wavelength selector are preferably removable and replaceable, so that the fluorometer is advantageously able to generate different excitation wavelengths and detect different emission wavelengths.

Abstract: Radiation curable compositions containing outstanding reactive diluents have been developed. The diluents are lower alkyl ether acrylates and methacrylates of particular alkoxylated and non-alkoxylated polyols.Examples are mono-methoxy trimethylolpropane diacrylate, mono-methoxy neopentyl glycol monoacrylate and mono-methoxy, ethoxylated neopentyl glycol monoacrylate having an average of about two moles of ethylene oxide.

Abstract: Radiation curable compositions containing outstanding reactive diluents have been developed. The diluents are lower alkyl ether acrylates and methacrylates of particular alkoxylated and non-alkoxylated polyols.Examples are mono-methoxy trimethylolpropane diacrylate, mono-methoxy neopentyl glycol monoacrylate and mono-methoxy, ethoxylated neopentyl glycol monoacrylate having an average of about two moles of ethylene oxide.

Abstract: Radiation curable compositions containing outstanding reactive diluents have been developed. The diluents are lower alkyl ether acrylates and methacrylates of particular alkoxylated and non-alkoxylated polyols.Examples are mono-methoxy trimethylolpropane diacrylate, mono-methoxy neopentyl glycol monoacrylate and mono-methoxy, ethoxylated neopentyl glycol monoacrylate having an average of about two moles of ethylene oxide.

Abstract: Radiation curable compositions containing outstanding reactive diluents have been developed. The diluents are lower alkyl ether acrylates and methacrylates of particular alkoxylated and non-alkoxylated polyols.Examples are mono-methoxy trimethylolopropane diacrylate, mono-methoxy neopentyl glycol monoacrylate and mono-methoxy, ethoxylated neopentyl glycol monoacrylate having an average of about two moles of ethylene oxide.

Abstract: Radiation curable compositions containing outstanding reactive diluents have been developed. The diluents are lower alkyl ether acrylates and methacrylates of particular alkoxylated and non-alkoxylated polyols.Examples are mono-methoxy trimethylolpropane diacrylate, mono-methoxy neopentyl glycol monoacrylate and mono-methoxy, ethoxylated neopentyl glycol monoacrylate having an average of about two moles of ethylene oxide.

Abstract: An optical system, useful as a magnetometer and as a polarization contoller, is disclosed. The system includes a source of electromagnetic radiation, a detector of electromagnetic radiation, and a magnetizable medium via which the source and detector communicate with one another. The system further includes apparatus for forming at least two adjacent magnetic domains separated by at least one domain wall.

Abstract: Radiation curable compositions containing outstanding reactive diluents have been developed. The diluents are lower alkyl ether acrylates and methacrylates of particular alkoxylated and non-alkoxylated polyols.Examples are mono-methoxy trimethylolpropane diacrylate, mono-methoxy neopentyl glycol monoacrylate and mono-methoxy, ethoxylated neopentyl glycol monoacrylate having an average of about two moles of ethylene oxide.

Abstract: Distributed region optical sensors for chemical detection are provided by utilizing optical fiber technology. A core is provided with a surrounding region that is permeable to the chemical to be detected. A composition whose optical characteristics are altered upon interaction with the chemical to be detected is provided within the permeable material. This change in optical characteristics allows chemical detection through detection of light guided by the fiber.

Abstract: A bidirectional fiber optic system is described in which at one terminal the output radiation of a light source (LED or semiconductor laser) is coupled through a small diameter hole in the active area of a photodiode into the core of a larger diameter transmission fiber. On the other hand, radiation propagating through the fiber in the opposite direction exits from the fiber with a large numerical aperture so that most of it is incident on the active area of the photodiode and little is lost through the hole. Also described are a number of photodiode configurations for use in such a system, as well as dual photodiodes to perform both signal detection and output monitoring functions. Further described are fiber optic sensing systems for monitoring such variables as blood pressure.

Abstract: A variable gap device which comprises a suitable material with a cavity formed therein mounted over a body. Elements are formed on the surface of the body and on the top surface of the cavity. In one embodiment, the elements are electrodes of a variable capacitance device, and in another embodiment the elements are partial or total reflectors of incident light from an optical fiber. The surface of the cavity opposite the body is preferably flat and of the order of microns from the body.The device is fabricated by forming a removable layer over a temporary substrate. An appropriate element pattern is formed over the removable layer and the layer is etched in a configuration which will define the cavity. The deformable material is encapsulated over this structure and then removed from the substrate with the element remaining in the cavity. Any removable material remaining in the cavity can then be etched away.