An OVNA system employing an array of reference delays to estimate distance-variant phase distortion in probe light during an optical-frequency sweep thereof. The estimated distance-variant phase distortion is then used to perform a phase correction for the digital electrical signals generated in response to the probe light being passed through a device under test (DUT) during the same optical-frequency sweep. Advantageously, the performed phase correction enables the OVNA system to provide a more-accurate determination of certain optical characteristics of the DUT than that achievable without such phase correction.

A multi-core fiber includes multiple optical cores, and for each different core of a set of different cores of the multiple optical cores, a total change in optical length is detected. The total change in optical length represents an accumulation of all changes in optical length for multiple segments of that different core up to a point on the multi-core fiber. A difference is determined between the total changes in optical length for cores of the set of different cores. A twist parameter and/or a bend angle associated with the multi-core fiber at the point on the multi-core fiber is/are determined based on the difference.

An optical device cut from a wafer into a chip by dicing, on the wafer, the optical device includes a plurality of optical waveguides; an optical circuit connected to the optical waveguide; and of the plurality of optical waveguides, a testing optical waveguide that guides test light to the optical circuit to be tested, by bypassing a non-connected optical waveguide portion at a terrace for mounting an optical chip component.

There is provided a method for measuring the PDL of a DUT as a function of the optical frequency ν within a spectral range, which uses a single wavelength scan over which the input-SOP varies in a continuous manner. The power transmission through the DUT, curve T(ν), is measured during the scan and the PDL is derived from the sideband components of the power transmission curve T(ν) that results from the continuously varying input-SOP. More specifically, the Discrete Fourier Transform (DFT) of the power transmission curve T(ν) is calculated, wherein the DFT shows at least two sidebands. At least two sidebands are extracted and their inverse DFT calculated individually to obtain complex transmissions (ν), =−J . . . J, where J is the number of sidebands on one side. The response vector |m(ν) of the DUT is derived from the complex transmissions (ν) and a matrix determined by the continuous trajectory of the SOP of the input test lightwave; and the PDL of the DUT as a function of ν (PDL curve) is derived therefrom.

A method and system for obtaining photonic parameters. The system includes a computer, an optical source, a first and second optical fiber, a Mach-Zehnder Interferometer (MZI) structure, and a detector. The computer includes a processor and memory. The optical source is constructed to emit light of a first optical mode and a second optical mode in response to an instruction by the computer. The first optical fiber receives the first or second optical mode. The MZI structure includes first and second pluralities MZIs and receives the first or second optical mode from the optical fiber. The second optical fiber receives light from the MZI structure. The detector is configured to receive light that propagated through the second optical fiber, generate image data and provide the image data to the computer. The computer obtains a plurality of photonic parameters based on the image data and initial guesses for the plurality of photonic parameters.

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.

Optical fabrication monitor structures can be included in a design fabricated on a wafer from a mask or fabrication reticle. A first set of components can be formed in an initial fabrication cycle, where the first set includes functional components and monitor structures. A second set of components can be formed by subsequent fabrication processes that can potentially cause errors or damage to the first set of components. The monitor structures can be implemented during fabrication (e.g., in a cleanroom) to detect fabrication errors without pulling or scrapping the wafer.

A method for inspecting a wafer includes: rotating the wafer about an axis of the wafer, emitting from a light source, two pairs of incident coherent light beams, each pair forming, at the intersection between the two beams, a measurement volume, a portion of the main wafer surface passing through each of the measurement volumes during the rotation, collecting a light beam scattered by the wafer surface, capturing the collected light and emitting an electrical signal representing the variation in the collected light intensity, detecting in the signal, a frequency, being the time signature of a defect through a respective measurement volume, for each detected signature, determining a visibility parameter, on the basis of the visibility determined, obtaining an item of information on the size of the defect, and cross-checking the items of information to determine the size of the defect.

Described are systems and techniques for characterizing optical fibers. Disclosed systems and techniques employ optical metrology, functional metrology, or both to characterize microstructured optical fibers and determine fiber characteristics, errors, and quality control metrics. The characteristics, errors, and quality control metrics are useful for improving the manufacturing of optical fibers.

Apparatus and methods are disclosed for measuring polarization properties and phase information, for example as can be used in microscopy applications. According to one example of the disclosed technology, an apparatus includes a light source, an interferometer configured to receive light generated by the light source and split the received light into two split beam outputs. The split beam outputs including combined, interfering light beams. Two light sensors, each including a polarization-sensitive focal plane array receive a respective one of the split beam outputs from the interferometer. Thus, some examples of the disclosed technology allows for simultaneous or concurrent measurement of properties of light including intensity, wavelength, polarization, and phase. The polarization-sensitive focal plane array includes a number of macropixels, each of which includes superpixels having different polarization filtering properties, each of which includes one or more pixels, which comprise filters for different colors.