Tektronix, Inc.

Mark D Marineau

Duwayne R Anderson

Steve U Reinhold

Lorimer L Twigg

William A Trent

Florian Gene Bell

Jeffrey H Goll

Richard I Lane

Friedrich Scheu

William K Bucher

An remote fiber test system includes a non-blocking N.times.N optical switch having N input ports and N output ports with one of the input ports coupled to a measurement test instrument for examining any of the optical fibers coupled to the output ports. The non-blocking switch includes a plurality of N input mechanical optical switches and an plurality of N output mechanical optical switches with each of the input mechanical optical switches having an input optical transmission path representing one of the input ports and each of the output mechanical optical switches having an output optical transmission path representing one of the output ports. Each input mechanical optical switch has N output optical transmission paths which each optical transmission path being coupled to one of the input optical transmission paths of each of the output mechanical optical switches. Each output mechanical optical switch has N input optical transmission paths with each optical transmission path being coupled to one of the output optical transmission paths of each input mechanical optical switch. Interconnecting optical transmission paths may be used to couple the N output optical transmission paths of the input mechanical optical switches with the input optical transmission paths of the output mechanical optical switches.

Remote fiber test system using a non-blocking N.times.N mechanical fiber

An remote fiber test system includes at least one mechanical optical switch has opposing input and output optical fiber bundles disposed within offset ferrules with at least one input fiber coupled to a measurement test instrument and each of the output fiber coupled to an optical fiber link via wavelength division multiplexers. Each ferrule of the optical switch is mounted in three-point kinematically correct V-groove holder allowing the optical fibers in each optical fiber bundle to traverse on a closed curve path during the rotation of the respective ferrules. The closed curve paths of each optical fiber in one of the optical fiber bundles intersect at least one of the closed curve paths of the optical fiber in the opposing optical fiber bundles. The intersection points of two opposing closed curve paths establish the optimum positioning locations for two opposing fibers.

Remote fiber test system using mechanical optical switches

A mechanical optical switch having opposing first and second optical transmission paths, such as optical fibers, forming an optical interface and rotating about respective independent and offset first and second rotational axes for positioning the fibers on respective first and second offset and intersecting closed curves operates to rotate the input or first optical fiber on its closed curve to one of the two intersecting points on its closed curve in response to the angular coordinate representative of the position of fiber at the intersecting point matching the intersecting point of the second optical fiber. The output or second optical fiber is rotated on its closed curve to the intersecting point corresponding to the intersecting point of the first fiber in response to the angular coordinate representative of the position of the second fiber at the intersecting point. These rotational movements may be performed sequentially, but in the preferred embodiment they are performed simultaneously. Since the offset closed curves intersect at two unique points, the speed of the switch may be increased by selecting the intersecting points closest to the input and output fibers prior to rotating the fibers. A plurality of optical fibers can rotate about one or both of the independent and offset rotational axes for establishing intersecting points on their respective closed curves.

Method of aligning opposing optical transmission paths in a mechanical

The angular coordinates representative of intersecting points on closed curves of a first optical fiber axially offset from a plurality of optical fibers in a mechanical optical switch are determined by imaging respective end faces of opposing first and second mounting members containing the respective fibers for determining the locations of the optical fibers in the mounting members and at least one reference point within one of the mounting members. The relative angular coordinates of the intersecting points between each of the closed curves of the plurality of optical fibers and the closed curve of the first optical fiber are aligned as a function of aligning the first optical fiber with the reference point. One of the plurality of optical fibers is optimally aligned with the first optical fiber at one of the intersecting points on the closed curves using the adjusted relative angular coordinates as the starting angular coordinates. The relative angular coordinates of intersecting points of the remaining plurality of optical fibers and the first optical fiber and the offset of the mounting members are readjusted relative to the optimally aligned optical fibers. The remaining optical fibers are optimally aligned with the first optical fiber at their respective intersecting points using the readjusted relative angular coordinates as the starting angular coordinates. The angular coordinates of the intersecting points of each of the optimally aligned plurality of optical fibers and the first optical fiber are stored.

Method of determining angular coordinates of opposing optical fibers in

An alignment apparatus for determining angular coordinates for offset and intersecting optical fibers in a mechanical optical switch has an analytical apparatus for imaging the end faces of the ferrules containing the opposing optical fibers of the switch for determining the respective axes of rotation of the mounting members, the locations of the optical fibers in the respective mounting members and coordinates of the optical fibers relative to the axis of rotation of the respective mounting members, the location of at least one reference point within one of the mounting members, and the relative angular coordinates of intersecting points between each of the closed curves of the plurality of optical fibers within the second mounting member and the closed curve of the first optical fiber as a function of the offset of the first and second mounting members and the reference point. The relative angular coordinates are passed to a measurement alignment apparatus for determining the angular coordinates of the intersecting points between each of the plurality of optical fibers and the first optical fiber as a function of optimally aligning the first optical fiber with each of the plurality of optical fibers.

Optical fiber alignment apparatus for a mechanical optical switch

An improved M.times.N mechanical optical switch has opposing input and output optical fiber bundles disposed within offset ferrules forming an optical interface with the ferrules having sleeve members secured to one of the end faces thereof. The sleeve members have a hardness greater than the ferules and the optical fibers for forming respective recessed polished end face regions on the ferrules at the optical interface. Each ferrule is mounted in three-point kinematically correct V-groove holder allowing the optical fibers in each optical fiber bundle to traverse on a closed curve path during the rotation of the respective ferrules. Each V-groove holder has a spring clamp with first and second clamp members and wear resistant inserts secured to the clamp members and the sidewalls of the V-groove holder. The closed curve paths of each optical fiber in one of the optical fiber bundles intersect at least one of the closed curve paths of the optical fiber in the opposing optical fiber bundles. The intersection points of two opposing closed curve paths establish the optimum positioning locations for two opposing fibers. Offsetting the axes of rotation of the opposing optical fiber bundles and mounting the bundles in a three-point kinematically correct holder produces a mechanical optical switch having superior cycle-to-cycle repeatability, long term repeatability, and absolute alignment using loosely toleranced components.

Mechanical optical switch

An address generator that provides equivalent time sampling for a time domain reflectometer generates read and write addesses for simultaneous application to an aquisition memory over an address bus. For each iteration of a repetitive input signal an excitation pulse is delayed by an amount, dt, that is an integer submultiple of a sampling period, T. Read addresses for each iteration of the repetitive input signal start from an initial address and increment by T/dt for each data sample. Corresponding write addresses are generated from the read addresses one sample time later so that the address on the address bus has a read address that is one address ahead of the write address. The acquisition memory reads out data from the read address for accumulation with corresponding sampled data while accumulated data is being input to the write address.

Address generator for high speed data averager

An automatic masking system is used in an optical time domain reflectometer for implementing a method of compensating for relaxation transients in an optical receiver in the OTDR. The masking system drives an optical modulator that masks the optical reciver from high amplitude optical pulses in the return reflected light from a fiber under test. A masking pattern corresponding to the high amplitude optical pulses is generated from a first acquisition of data with the receiver unmasked from the return reflected light. The masking pattern is stored and used for generating a signal from the masking system to the optical modulator for blocking the high amplitude optical pulses in the return reflected light during a subsequent acquisition of data. In a third acquisition of data of the return reflected light, the optical modulator masks the receiver from the return reflected light. Combining the acquired data of the blocked return reflected light with the acquired data with the high amplitude optical pulses blocked, produces an output free of relaxation transients produced by the receiver. Combining the high amplitude optical pulse data from the first acquisition with the output from the subtracted acquisitions produces an output representative of the return reflected light.

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Redmond, OR, United States of America

Mark D Marineau