Abstract: There is presented an apparatus and method of locating a reflective anomaly in an optical fiber. An optical generator is positioned at one end of a light path extending to and from a reflective anomaly in an optical fiber, and periodic pulses of light are injected into the fiber. A bend coupler containing directional optical detectors is clamped to the optical fiber in mid-span, between the optical generator and a reflective anomaly, and light energy is tapped. The coupler is capable of detecting and discriminating light travelling in both longitudinal directions. After signal conditioning and digitization, the light pulses are submitted to a logical network to initiate a timer that measures a time interval between the event of an interrogating light pulse, and its reflection, the result being memorized in a buffer. A microprocessor controls the system, and computes distance between the attached bend coupler and the reflective anomaly as a function of the memorized time interval.
Abstract: A passive distribution net connects a host digital terminal to a number of optical network units which service respective subscribers. Transmit and receive feeder fibers branch out to the optical network units with optical power splitters. An out-of-band laser light is blended with the communications wavelength on the transmit feeder at the host digital terminal and is stripped at the receive feeder using wave division multiplexers. Similar wave division multiplexers at the optical network units are coupled by an optical shunt to carry the out-of-band light around each optical network unit. This arrangement monitors network integrity and can discern fiber failure from optical network unit failure.
Abstract: A splice loss tester for optical fiber splices has two light launch stations and a detection station. The light launch stations each have an optical coupling block formed of acrylic or other transparent material, with a concave surface on which an arcuate segment of the fiber is lightly biased by a cylindrical anvil. A photoemitter in optical contact with the coupling block generates light at a suitable wavelength (e.g. 1550 nm). A clear silicon gel layer on the block concave surface can hasten fiber stabilization. The detection station has a similar coupling block and anvil, and a pair of photodetectors to detect light leakage in each of two directions. The light is launched or detected over a substantial arc of the fiber, i.e., about ninety degrees, and the launch and detection units are useful over a wide range of wavelengths.
Type:
Grant
Filed:
June 17, 1992
Date of Patent:
May 24, 1994
Assignee:
Laser Precision Corp.
Inventors:
Hosain Hakimi, Scott Bagetis, Walter Williams, Howard Sins, Dennis Marolf
Abstract: An optical apparatus is disclosed which monitors the thickness of a thin film carried by a reflecting substrate. In order to minimize light detection problems caused by inadvertent displacement of the substrate, the light source and detector are located on the same "side" of the optical apparatus, and retro-reflector means are located at the other "side" of the optical apparatus, so that the light is reflected from the substrate to the retro-reflector means, back to the substrate, and thence back to the detector. In the preferred embodiment, the retro-reflector means comprises an array of small retro-reflectors.