In some examples, fiber optic cable location may include transmitting a coherent laser pulse into a device under test (DUT). Based on an analysis of reflected light resulting from the transmitted coherent laser pulse, changes in intensity of the reflected light caused by a plurality of signals directed towards the DUT may be determined. Further, based on the changes in intensity of the reflected light, a location of the DUT may be determined.

A light physical constant measurement method includes: virtually dividing an optical transmission medium along a propagation direction to set a plurality of first segments; and estimating light physical constants of the plurality of first segments based on the result of a first propagation simulation that uses a model in which an input optical signal of each of the plurality of intensities propagates sequentially through the plurality of first segments, and in the estimating of light physical constants of the plurality of first segments, the light physical constants of the plurality of first segments are searched for using an evaluation function of evaluating a difference between a measured power spectrum of an output optical signal and a power spectrum of the output optical signal obtained as a result of the first propagation simulation, to estimate the light physical constants of the plurality of first segments.

One or more modal characteristics are determined for a waveguide that supports more than two modes. In an example implementation, optical frequency domain reflectometry (OFDR) is used to couple light into the waveguide and detect Rayleigh scatter reflections associated with a segment of the waveguide. An original set of Rayleigh scatter data associated with the detected Rayleigh scatter reflections is generated. In addition, a scaled set of Rayleigh scatter data associated with the detected Rayleigh scatter reflections is generated. The original set of Rayleigh scatter data is correlated with the scaled set of Rayleigh scatter data. One or more modal characteristics of the waveguide are determined based on the correlation.

A line monitoring system may include a laser source to launch a probe signal over a first bandwidth, a polarization maintaining tap to receive and split the probe signal, into a first portion and a second portion, a polarization rotator to receive the first portion and send the first portion to a transmission system, a return tap to receive the second portion and to receive a return signal from the transmission system, wherein the return signal being derived from the first portion, a photodetector coupled to receive an interference signal from the return tap, wherein the interference signal is generated by a mixing the return signal and the second portion, where the photodetector is arranged to output a power signal based upon the interference signal, and a power measurement system to measure the power signal at a given measurement frequency over a second bandwidth, comparable to the first bandwidth.

An optical sensing fiber includes multiple reference reflectors spaced along a length of the fiber. Each of the multiple reference reflectors producing a reference scattering event having a known scattering profile including an elevated amplitude relative to scattering detected for neighboring segments of the optical fiber. Each of the segments is a length of contiguous fiber that is useable to initialize and perform a distributed Optical Frequency Domain Reflectometry (OFDR) sensing operation. An OFDR interrogation system is disclosed that measures a parameter using the optical sensing fiber.

An optical sensing fiber includes multiple reference reflectors spaced along a length of the fiber. Each of the multiple reference reflectors producing a reference scattering event having a known scattering profile including an elevated amplitude relative to scattering detected for neighboring segments of the optical fiber. Each of the segments is a length of contiguous fiber that is useable to initialize and perform a distributed Optical Frequency Domain Reflectometry (OFDR) sensing operation. An OFDR interrogation system is disclosed that measures a parameter using the optical sensing fiber.

A time domain reflectometry measurement apparatus and method is provided. Measurement data of a time domain reflectometry measurement are analyzed with respect to previously acquired empirical measurement data of error-free or faulty devices with known failures. In this way, failures can be identified in the device under test without the need of opening the device.

Brillouin fiber sensors can provide distributed measurements of parameters of interest over long distances in a fiber by measuring the Brillouin frequency shift as a function of position along the fiber. The Brillouin frequency shift may be determined, to within a small fraction of the Brillouin linewidth, by establishing a series of lasing modes that experience Brillouin amplification at discrete spatial locations in a test fiber. A linewidth narrowing and high intensity associated with the lasing transition enable precise measurements of the lasing frequency associated with each of the lasing modes. The Brillouin frequency may be determined based on the lasing frequency.

A module housing case is described. The modular housing case includes a fiber optic component housing defined as a cavity that is sized to receive a fiber optic connector. Within the cavity is a ferrule guide. The module housing case also has an internal cavity that is at least partially enclosed. Components to assist in magnification may be disposed at least partially within the internal cavity. Finally, the module housing case employs a camera lens alignment feature.

The disclosure relates to the measurement of temporal characteristics of optical pulses. Embodiments may be used for single-shot characterization of picosecond optical pulses. The optical pulse may be split into a plurality of ancillary pulses. Amounts of distortion may be added to the plurality of ancillary pulses. An instantaneous power of the plurality of ancillary pulses may be measured. Thereafter, an experimental trace with the measured instantaneous powers may be constructed and the experimental trace may be outputted. The experimental trace may be processed to calculate temporal characteristics of the input optical pulse. A fiber assembly may be used to split the pulse into the plurality of ancillary pulses. The fiber assembly may include one or more splitters. The one or more splitters may direct the ancillary pulses along different optical paths having different lengths to temporally separate the ancillary pulses and to add amounts of distortion.