Abstract: There is disclosed an arrangement for tapping signal power from an optical fiber waveguide without requiring that the fiber be terminated or broken. An intermediate length of a fiber waveguide from which all or most of the outer cladding has been removed is sandwiched between first and second dielectric bodies, each illustratively in the form of a circular disk. The first body, which serves to couple optical power out of the fiber, is formed of a relatively compliant dielectric material, such as a soft plastic, having an index of refraction approximately equal to, or greater than, that of the outer cladding of the fiber. The second body is formed of a relatively hard dielectric material, such as a glass or hard plastic, having an index of refraction less than that of the first body. The two dielectric bodies and the fiber are placed in a specially designed holder and forced together so that the fiber deforms the first body providing a large area of contact therewith.

Abstract: A filter having a cut-off frequency of the order of 50Hz is included in the circuit of flame monitoring apparatus to remove signals below the cut-off frequency. In the circuit shown, a silicon p-n junction photo-electric pick-up is capacitively connected to an amplifier, the amplifier is connected to a high-pass filter, the output of the filter is connected to a further amplifier, the output of the further amplifier is applied to a detector integrator, the output of the detector integrator is connected to a Schmitt trigger, and the output of the trigger is applied to an output circuit giving a warning signal if the flame being monitored is extinguished. The use of sighting tubes for the photo-electric pick-ups is disclosed.

Abstract: A film inspection apparatus is provided for detecting changes in surface profile of film, e.g., edge breaks sprocket hole tears, poor splices, etc. The film inspection apparatus includes a device mounted above a sapphire film support and having a pair of cantilever jewel carrying members for feeling the surface profile adjacent each edge of a traveling web of film. Each cantilever includes a thin vane which extends into and modulates a respective light beam which is incident upon a respective photocell. Each photocell is connected to a separate channel of a braking circuit to operate a brake for the film driving mechanism when a surface profile is encountered which is to be considered as an unacceptable flaw.

Abstract: An optical scanning system has a dirigible head of generally spherical shape mounted on a support body for scanning through a substantially hemispherical field of view, and optical lenses, a scanner rotor and drive motor therefor, and a cryogenically-cooled detector element array are all mounted within the confines of the dirigible head. The head has a primary objective lens in its outer shell and further lenses are mounted within the head in an adjustable holder enabling different lenses to be brought into alignment with the objective lens. The scanner rotor is generally annular and rotates about an axis oblique to the optical axis of the objective lens; it comprises a multi-faceted reflector receiving the image beam from the lens system and reflecting it laterally on to the detector array.

Abstract: Apparatus for maintaining image definition and intensity in optical image processing operations. The apparatus comprises an improved photosensitive device responsive to an applied radiation image pattern for establishing internal electric fields each of which are representative of the intensity of different portions of the applied pattern. Associated with the photosensitive device are a plurality of transparent, conductive targets or conductors aligned to receive the different portions of the applied radiation pattern and to establish discrete internal fields in the device which are uniform over the area of each target notwithstanding any non-uniformities that might exist in the intensity distribution of any of the portions of the applied pattern.

Abstract: A Bragg cell spectrum analyzer in which the output of the Bragg cell is detected by a unique electro-optic system which allows the selection of any desired dynamic power detection range. As is known in the art, the output of a Bragg cell consists of a radiation spot or spots along a line in which the position of each spot along the line is related to the frequency of a component of the input signal to the Bragg cell, and the intensity of radiation of each spot is proportional to the strength of the component causing that spot. In the disclosed embodiment the output of the Bragg cell is directed upon a cylindrical lens system which expands each spot into a line of radiation. This results in a two dimensional pattern of lines with the position of each line being the same as the position of the radiation spot causing the line, and the intensity of radiation in each line being proportional to the intensity of radiation in the spot causing that line.

Abstract: In the radiometric apparatus disclosed herein, radiant energy from a target is chopped before reaching a detector element. The same detector element receives radiation from a light-emitting diode which is periodically energized in synchronism with the chopping, the level of the energization of the light-emitting diode being varied as a function of a feedback signal obtained by synchronously demodulating the detector signal. In this manner, the a.c. component of the detector signal is driven to a null balance, the level of energization of the light-emitting diode at balance being indicative of the level of radiation received from the target.

Abstract: In an optical fiber power tap, signal power is coupled out of an optical fiber waveguide by a dielectric body disposed in a coupling relationship laterally offset from an intermediate length of the fiber, and is converted to a representative electrical signal suitable for utilization by a photodetector disposed adjacent to the dielectric body. In accordance with the disclosed invention, the operation of the fiber tap is improved by combining therewith means for coupling a portion of the signal power in the fiber from lower order modes to higher order modes. The mode coupling means illustratively comprises a pair of corrugated plates which is pressed against the fiber to periodically deform a region of the fiber just preceding the fiber tap.

Abstract: A detector of blemishes in a surface comprises a transmitting station from which a beam of light is caused to scan a moving surface to produce a raster pattern thereon. Light specularly reflected from, or transmitted by, the surface is collected at a receiving station after being diffused by a sheet of translucent material disposed in the path of this light. The diffused light in the receiving station is collected and directed by reflective surfaces towards a photodetector such that when the beam engages a blemish in the surface, the amount of light detected falls. The detector combines the sensitivity of collecting large amounts of specularly reflected light with a simple optical system associated with the collecting of diffused light.

Abstract: In an optical switching system having a transmitter and a receiver optically coupled together via a fiber optic light guide, the transmitter utilizes a piezoelectric device which provides an electrical signal to a light emitting device when a mechanical strain is imparted to the piezoelectric device. The light emitted by the light source is provided at the receiver via the fiber optic guide. The receiver generates a signal in response to the light received thereat via the fiber optic guide. This generated signal is used to control the power flowing to a load via a switching device so that, for example, one generated signal is used to turn on the switching device and the next succeeding generated signal is used to turn off the switching device.