In this invention, a novel technique is introduced to measure chromatic dispersion (CD) in optical fibers. This technique is based on a relatively low-frequency optoelectronic oscillation (OEO) to provide fast, precise and low cost method for CD measurement that can be implemented easily in commercial instruments. In addition, another technique is presented to compensate for fiber thermal fluctuations during measurement which is based on a second simultaneously oscillating OEO. The proposed setup is implemented to measure the CD in normal single mode fibers with lengths of 40 km, 10 km, 1 km. Moreover, it is implemented to measure CD in 400 m of nonzero dispersion shifted fiber to test the system ability to resolve small chromatic delays. The proposed setup can resolve delays less than 0.1 ps/nm (which can be further improved by increasing the oscillation frequency) and measure CD with precision as low as 0.005 ps/nm.km as low as 20 seconds over a wavelength range from 1500 to 1630 nm. Further improvements may be possible by slightly better system design.

An optical fiber array includes: a support; a single-mode optical fiber and a plurality of multimode optical fibers, the single-mode optical fiber and the multimode optical fibers being arranged on the support; and a polarizing plate provided on an end face of the support, wherein the single-mode optical fiber has polarization maintaining characteristics, an end face of the single-mode optical fiber and end faces of the multimode optical fibers face the end face of the support, and the polarizing plate covers the end faces of the multimode optical fibers.

A non-contact system for measuring an insertion loss of a cable assembly with cable fibers includes a light source system that emits light and a launch connector supporting launch fibers. A detector system includes receive fibers supported by a receive connector. The detector system has detectors optically coupled to the receive fibers, with one detector directly optically coupled to the light source system for calibration. A first movable stage supports the launch connector and a second movable stage supports the receive connector. A launch optical system images output end faces of the launch fibers onto input end faces of the cable fibers of the cable assembly. A receive optical system images output end faces of the cable fibers onto input end faces of the receive fibers. The light exiting the receive fibers is detected and processed to determine the insertion loss of the cable assembly.

A method of characterizing a multimode optical fiber results in a measure of estimated modal bandwidth (EMB) that is independent of the bandwidth of the light used in the characterization. The method includes propagating pulses of light along the multimode optical fiber at prescribed radial positions relative to an optical axis of the multimode optical fiber and detecting output pulses from the multimode optical fiber corresponding to the pulses of light propagated along the multimode optical fiber at the prescribed radial positions relative to the optical axis of the multimode optical fiber. An estimated modal bandwidth of the multimode optical fiber is calculated in a manner that accounts for chromatic dispersion of the multimode optical fiber.

A deformometer includes: a cavity body; entry and exit optical cavity optics, such that the optical cavity produces filtered combined light from combined light; a first laser that provides first light; a second laser that provides second light; an optical combiner that: receives the first light; receives the second light; combines the first light and the second light; produces combined light from the first light and the second light; and communicates the combined light to the entry optical cavity optic; a beam splitter that: receives the filtered combined light; splits the filtered combined light; a first light detector in optical communication with the beam splitter and that: receives the first filtered light from the beam splitter; and produces a first cavity signal from the first filtered light; and a second light detector that: receives the second filtered light; and produces a second cavity signal from the second filtered light.

A photonic testing device includes a substrate, an optical device under test (DUT) disposed over the substrate, and an optical input circuit disposed over the substrate. The optical input circuit includes a first plurality of inputs each configured to transmit a respective optical test signal of a plurality of optical test signals. Each of the plurality of optical test signals includes a respective dominant wavelength of a plurality of dominant wavelengths. The optical input circuit further includes an output coupled to an input waveguide of the optical DUT. The output is configured to transmit a combined optical test signal comprising the plurality of optical test signals.

A method is used to select a multimode fiber meeting requirements of a first minimum bandwidth at a first wavelength and a second minimum bandwidth at a second wavelength different from the first wavelength. Differential mode delay (DMD) data is measured for the multimode fiber at the first wavelength. The DMD data comprises output laser pulse data as a function of the radial position of an input laser pulse having the first wavelength. The DMD data is transformed into mode group space, to obtain relative mode group delay data as a function of mode group. The multimode fiber is selected based on meeting requirements of the first minimum bandwidth at the first wavelength based on a first set of criteria, comprising a first criterion using as input the measured differential mode delay (DMD) data for the multimode fiber measured at the first wavelength. The multimode fiber is selected based on meeting requirements of the second minimum bandwidth at the second wavelength based on a second set of criteria, comprising: a second criterion using as input the relative mode group delay data. A related system is also described.

In a measurement method, light inputs with the same center wavelength and different properties are performed on a light transmission medium, and a measured value of an intensity spectrum of each of light outputs is acquired. An error between the measured value and an estimated value of the intensity spectrum calculated based on a theoretical relation between an intensity spectrum and a phase spectrum of each of the light inputs, a nonlinear coefficient and a wavelength dispersion value of the light transmission medium, and the intensity spectrum of each of the light outputs is calculated while changing the nonlinear coefficient and the wavelength dispersion value. Further, the nonlinear coefficient and the wavelength dispersion value are determined based on a difference, in a relation between the nonlinear coefficient and the wavelength dispersion value and the error, between the light inputs.

An optical testing device is provided. The testing device includes a position sensing detector (PSD) having an optical sensing area that is optically responsive to a first range of wavelengths. The PSD receives a plurality of optical signals having wavelengths within the first range and emitted through a respective plurality of optical fibers and detects a plurality of positions where the optical signals impinged on the optical sensing area for determining array polarity. The PSD receives a plurality of first optical signals having wavelengths within the first range and detects the polarity and a plurality of optical intensities of the first optical signals. The testing device includes a photodetector that is optically responsive to a second range of wavelengths different than the first range. The photodetector receives a plurality of second optical signals within the second range and detects a plurality of optical intensities of the second optical signals.

The invention concerns an optoelectronic chip including a pair of optical inputs having a same bandwidth, and each being adapted to a different polarization, at least one photonic circuit to be tested, and an optical coupling device configured to couple the two inputs to the circuit to be tested.