Abstract: A scanning system for wood products to detect grain defects and product geometry simultaneously. Multiple scanner sets cast parallel beams of light at an angle of incidence in a plane that is normal to the surface of the wood product. Scanner sets are provided to scan both the top and bottom surfaces of the wood product. The scanner sets include detector arrays to detect the reflected light of the beams off the surface of the product. One array of each set is positioned strategic to the angle of incidence and another is positioned strategic to the angle of specular reflection. The magnitudes of the detector are compared to determine clear wood or grain defect. The time of detection is used to calculate thickness/geometry.

Abstract: A system includes a catheter (10) having a low pressure balloon (42) at of one end thereof, a precise, low pressure, low volume fluid infusion means (41) and a pressure sensor (43). The balloon (42) is introduced to a body lumen, such as a blood vessel, and inflated to a pressure at or just above physiologic, typically being below 200 mmhg. From the balloon volume at a particular pressure, the internal cross-sectional area and diameter of the vessel can be calculated. Additional calculations can be made at other pressures below 200 mmhg to determine compliance of the vessel.

Abstract: A spectrum shifting optical switch in which an optical beam splitter couples input light from a light source to a manually movable spectral modulation element and couples output light from the spectral modulation element to a light detector. The spectral modulation element may be an optically resonant cavity having a manually movable diaphragm, thereby changing the resonant wavelength of the cavity. As a result, the wavelength spectrum of the input light is altered by the resonant wavelength of the cavity. The spectral modulation element may also be an optical filter through which the input light passes. The resulting spectral modulation of the input light is detected to determine the position of the resilient diaphargm or filter.

Abstract: An optical pressure-sensing system in which an optical beam splitter couples input light from a light source to an optically resonant pressure sensor and couples output light reflected from the sensor to a light detector. The light detector may divide the output light into bands having different wavelengths and then take the ratio of the light in one band to the light in the other band in order to provide an output that is insensitive to various spurious responses in the system. The optical beam splitter may be formed by two pairs of graded refractive index lenses. A partially reflective, partially transmissive mirror is sandwiched between the lenses of one pair, while a dichroic mirror is sandwiched between the second pair. The pairs of lenses are placed in abutting relationship to each other. The optical beam splitter may also be formed by a block of transparent material having a partially reflective, partially transmissive mirror on one edge.

Abstract: A method of mapping at least a portion of a magnetic field with an interferometer is presented. The interferometer includes an optical fiber clad with a magnetostrictive material. The approximate direction of the magnetic field lines are determined and the optical fiber is placed substantially transverse to the magnetic field lines. The output of the interferometer is recorded for various positions of the optical fiber. The fiber can be maintained substantially transverse to the magnetic field lines during mapping, or the fiber can be positioned substantially transverse to the field lines to precisely determine the direction of field lines and substantially parallel to the field lines to determine field magnitude. In one embodiment the interferometer is adapted to produce a null output for a predetermined value of the integral of the magnetic field along the length of the optical fiber, and the optical fiber is of uniform construction.

Abstract: A method of mapping at least a portion of a magnetic field with an interferometer is presented. The interferometer includes an optical fiber clad with a magnetostrictive material. The approximate direction of the magnetic field lines are determined and the optical fiber is placed substantially transverse to the magnetic field lines. The output of the interferometer is recorded for various positions of the optical fiber. The fiber can be maintained substantially transverse to the magnetic field lines during mapping, or the fiber can be positioned substantially transverse to the field lines to precisely determine the direction of field lines and substantially parallel to the field lines to determine field magnitude. In one embodiment the interferometer is adapted to produce a null output for a predetermined value of the integral of the magnetic field along the length of the optical fiber, and the optical fiber is of uniform construction.

Abstract: An optical fiber is processed by ablating cladding material with an intense electromagnetic energy source. The intensity of another beam directed along the propagation axis of the fiber is monitored to detect near exposure of the fiber core. The ablating electromagnetic energy source is preferably circularly polarized. Apparatus for performing this process is disclosed. Fibers produced by this process are used to form optical couplers or, when a metallic layer is provided over the nearly exposed core region, an optical polarizer.

Abstract: An optical imaging device includes an optical device comprising means for absorbing at least one wavelength of light incident thereupon, a first layer of a first material having a first index of refraction and being in thermal contact with the absorbing means, and a second layer of a second material having a second index of refraction which is larger than the first index of refraction and which forms an interface with the first layer. The first layer is placed between the absorbing means and the second layer. The phase, amplitude or both phase and amplitude of the reflected light can be modulated by thermally induced changes in the first index of refraction. A method of modulating a first optical beam with a second optical beam is also provided.

Abstract: An optical coupler for use with a plurality of fiber optics to couple any signal which may appear on any one or more of the input ends of the fibers so that at least a portion of such signal appears at the output ends of such fibers.

Abstract: A low frequency detection system including the use of the sloping characteristics of the underwater near shore, the tapered section of ocean above the near shore, and an acoustic array. The acoustic array comprises a plurality of detectors that extend into the earth and are near the shore and tapered media. Low frequency sound energy in the range of from about 1 to about 100 Hz is coupled into the earth at discrete positions along the interface between the ocean and the sloping underwater shore. The maximum energy density for each frequency occurs at different ocean depths and the acoustic detectors are positioned to receive the optimum earth radiated beam at selected frequencies. The system involves locating tuned elements of an array in different arrangements and using a plurality of arrays and moving or stationary sound sources for active target detection and underwater earth mapping.