Abstract: Various embodiments of an apparatus for measuring a characteristic parameter of an optical fiber are provided. In one embodiment, an apparatus for testing an optical fiber comprises: a light source enclosed within a housing and configured to couple to a first end of the optical fiber; a detector enclosed within the housing and configured to couple to a second end of the optical fiber; and a non-planar table defining a curved path, the non-planar table attached to the housing and configured to guide the optical fiber along the curved path in three dimensions. In this way, an optical fiber may be deployed for testing with minimal manual manipulation of the optical fiber.

Abstract: A passive optical element defining an optical propagation path is tested by coupling a buffer fiber between an input of the propagation path and an optical time domain reflectometer. The OTDR launches optical radiation into the buffer fiber via one end thereof, measures power level of return light received at the OTDR via the buffer fiber, and creates an OTDR signature representing power level of return light as a function of distance from the end of the buffer fiber. The OTDR selects a first marker point by applying data reduction to a portion of a segment of the OTDR signature corresponding to the buffer fiber, selects a second marker point downstream of the input of the optical propagation path, and calculates a first power difference value as difference between a power level at the first marker point and a power level at the second marker point.

Abstract: A passive optical element defining an optical propagation path is tested by coupling a first end of a first buffer fiber to an input of the optical propagation path and coupling a second end of the buffer fiber to an optical time domain reflectometer (OTDR). The OTDR launches optical radiation into the first buffer fiber via the second end thereof, measures power level of return light received at the OTDR via the second end of the first buffer fiber, and creates a first OTDR signature representing power level of return light as a function of distance from the second end of the first buffer fiber. The OTDR selects a first marker point by applying data reduction to at least a portion of a segment of the first OTDR signature corresponding to the first buffer fiber, selects a second marker point downstream of the input of the optical propagation path, and calculates a first power difference value as difference between a power level at the first marker point and a power level at the second marker point.

Abstract: Distortion introduced by an imaging system is characterized by positioning a generally cylindrical object and imaging optics in a first relative angular position about an axis of rotation that substantially coincides with the longitudinal axis of the object and employing the imaging optics to image the end face of the object on a detector. First and second definitions of the shape of the image of the periphery of the end face of the object are extracted from image data provided by the detector when the object and the imaging optics are in first and second relative angular positions. The first and second definitions are compared.

Abstract: An optical test instrument, for testing response of an optical medium to optical energy, comprises a light source for emitting optical energy in response to electrical energy, a detector for providing an electrical output signal in response to incident optical energy, and a propagation path for delivering optical energy from the light source to the medium under test and for delivering optical energy from the medium under test to the detector. A positioning mechanism displaces an optical attenuator element between a first position, in which it is out of the propagation path, and a second position, in which it is interposed in a segment of the path in which the optical energy is propagated as a beam.

Abstract: An optical multiplexer comprises a signal energy divider, such as a directional coupler, for dividing optical signal energy received by way of a multiplexer upstream port into a control portion and a utilization portion, and an optical switch having a first switch port connected to receive the utilization portion of the optical signal energy and having a plurality of additional switch ports connected to repsecive multiplexer downstream ports. A decoder extracts a control message from the control portion of the optical signal energy, and a controller is responsive to the control message for selectively setting the switch to interconnect the first switch port and a selected one of the additional switch ports. In this manner, at least part of the utilization portion of the optical signal energy received by the multiplexer by way of the multiplexer upstream port is emitted from the multiplexer by way of the multiplexer downstream port that is connected to the selected one of the additional switch ports.

Abstract: Apparatus for optically coupling first and second optical fiber segments comprises a base frame (10), a support (14, 18) for supporting the second fiber segment relative to the base frame in an orientation in which its central axis is aligned with a horizontal optical axis (72), and a first displacement mechanism (40-64) for supporting the first fiber segment in a coaxially aligned relationship with the second fiber segment. The first displacement mechanism is operable selectively to displace the first fiber segment along the horizontal optical axis. A cup (122) contains a bath of index-matching liquid and is supported at a position below the horizontal optical axis. A second displacement mechanism (108, 110) supports a dipper (114, 118) so that the dipper is displaceable along a path such that a drop retaining portion of the dipper is first placed within the cup and is then raised so that the drop retaining portion of the dipper lies on the horizontal optical axis.

Abstract: Apparatus for optically coupling first and second optical fiber segments comprises a base frame (10), a support (14, 18) for supporting the second fiber segment relative to the base frame in an orientation in which its central axis is aligned with a horizontal optical axis (72), and a first displacement mechanism (40-64) for supporting the first fiber segment in a coaxially aligned relationship with the second fiber segment. The first displacement mechanism is operable selectively to displace the first fiber segment along the horizontal optical axis. A cup (122) contains a bath of index-matching liquid and is supported at a position below the horizontal optical axis. A second displacement mechanism (108, 110) supports a dipper (114, 118) so that the dipper is displaceable along a path such that a drop retaining portion of the dipper is first placed within the cup and is then raised so that the drop retaining portion of the dipper lies on the horizontal optical axis.

Abstract: A method of aligning first and second substantially parallel rod-form elements, such as optical fibers, comprises placing the first element at a position at which it is approximately aligned with the second element and is in the fields of view of two imaging systems that have respective axes that are oblique to each other and to the central axes of the two rod-form elements, and digitizing at least a part of the image of each field of view. The digital data is analyzed to determine location of the first element in each field of view, and relative displacement of the first and second elements is brought about accordingly.

Abstract: A method of testing a length section of optical fiber in order to determine whether the angle between an end face of the length section and a plane perpendicular to a longitudinal axis of the length section of optical fiber is within a predetermined range, comprises positioning the length section of optical fiber so that its longitudinal axis substantially coincides with the optical axis of a camera, selecting at least two test regions on the end face of the fiber, adjusting the position of at least one of a camera, a lens and the length section of optical fiber to focus each of the test regions on the sensing surface of the camera, and comparing the adjustments performed in the preceding step for the two test regions respectively.

Abstract: A clamp for gripping an elongate member comprises a mounting block having locating structures defining a desired position for the elongate member. Primary and secondary clamping yokes are each movable relative to the mounting block between a closed position, in which the clamping yoke engages an elongate member in the desired position, and an open position. A latch retains the primary clamping yoke in the closed position, and a force-transfer arm is effective between the primary clamping yoke and the secondary clamping yoke for retaining the secondary clamping yoke in its closed position when the primary clamping yoke is in its closed position.

Abstract: Apparatus for testing multiple optical fibers comprises a light source, a light detector, a first set of adapter fibers, and a second set of adapter fibers corresponding on a one-to-one basis with the first set of adapter fibers. A first end of each fiber of the first set is held in a first fiber holding structure, and a first translation mechanism is provided for translating the first fiber holding structure relative to the light source so as to bring the first end of any selected one of the first set of adapter fibers into optically coupled relationship with the light source. A first end of each fiber of the second set is held in a second fiber holding structure, and a second translation mechanism is provided for translating the second fiber holding structure relative to the detector to bring the first end of any selected one of the second set of adapter fibers into optically coupled relationship with the light detector.

Abstract: An optical time domain reflectometer comprises a detector device for detecting optical energy received at an end of a fiber under test, an amplifier having an input terminal connected to the detector device, and a photoconductive switch connected between the amplifier input terminal and a reference potential level. The photoconductive switch is selectively illuminated.