A system for providing information based on a spectral content of an optical signal, comprises: an optical modulator for applying a time-dependent modulation to the optical signal according to at least one sub-optical modulation frequency, to provide a modulated optical signal. The system also comprises an optoelectronic device configured for receiving the modulated optical signal and responsively generate an electrical sensing signal, and a signal processing system configured for processing the electrical sensing signal and to generate output correlative to at least one wavelength of the optical signal based on the modulation.

A method including transmitting an intensity-modulated light through a mode conditioner to generate a mode-conditioned intensity-modulated light in one or a plurality of launch conditions and transmitting the mode-conditioned intensity-modulated light through a multimode optical fiber under test (FUT) to excite a plurality of modes of the FUT. The method further includes converting the mode-conditioned intensity-modulated light transmitted through the FUT into an electrical signal, measuring, based on the electrical signal, a complex transfer function CTF(f) of the FUT, and obtaining an output pulse based on the measured complex transfer function CTF(f) from one or a plurality of launch conditions and an assumed input pulse using the equation: P.sub.out (t)=.sup.−1(CTF(f)*(P.sub.in(t))). Wherein, P.sub.out (t) is the output pulse, .sup.−1(CTF(f)*(P.sub.in(t))) is the inverse Fourier transform of the function CTF(f)*(P.sub.in (t)), and (P.sub.in(t)) is the Fourier transform of the assumed input pulse. Additionally, the method includes calculating modal bandwidth of the FUT based on P.sub.out(t).

A test instrument tests an optical component of a fiber optic network. The test instrument determines signal parameters describing pulses to be emitted by lasers of the test instrument to test the optical component, and directly modulates the lasers to repeatedly emit the pulses at different wavelengths on a single fiber optic cable in a time division multiplexing manner. The test instrument triggers powering measurements to coincide with the emitted pulses, and determines performance parameters of the optical component based on the triggered power measurements.

Provided are an optical spectrum analyzer and a pulse-modulated light measurement method capable of measuring pulse-modulated light even when a pulse-on time and a pulse period of the pulse-modulated light are unknown. Pulse-modulated light (DUT) is incident on a diffraction grating 3. A first light receiving unit 8 receives the 0th-order light of diffracted light diffracted by the diffraction grating 3. A second light receiving unit 7 receives diffracted light of an order other than the 0th-order light. A measurement timing signal generation unit 9 generates a sampling signal based on the 0th-order light received by the first light receiving unit. The spectrum of the diffracted light received by the second light receiving unit is measured based on the sampling signal generated by the measurement timing signal generation unit.

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.

Disclosed is a method of characterizing a multimode optical fiber link including a light source and two or more multimode fibers. The method includes a step of characterizing each of said multimode fibers using a measurement of the Dispersion Modal Delay (DMD) for each of said multimode fibers, and delivering, for each of said multimode fibers, at least three fiber characteristic curves as a function of a radial offset value r; a step of characterizing the light source by at least three source characteristic curves showing at least three parameters of the source as a function of a fiber radius r and obtained by a technique similar to the DMD measurement; and a step of computing an Effective Bandwidth (EB) of the link, comprising calculating a transfer function using both each of said source characteristic curves and each of said at least three fiber characteristic curves for each of said multimode fibers.

A system (20) for fiber-optic reflectometry includes an optical source (28, 40), a beat detection module (52, 56) and a processor (36). The optical source is configured to generate an optical interrogation signal that is transmitted into an optical fiber (24). The beat detection module is configured to receive from the optical fiber an optical backscattering signal in response to the optical interrogation signal, and to mix the optical backscattering signal with a reference replica of the optical interrogation signal using In-phase/Quadrature (I/Q) mixing, so as to produce a complex beat signal having In-phase (I) and Quadrature (Q) components. The processor is configured to sense one or more events affecting the optical fiber by analyzing the I and Q components of the complex beat signal.

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.

A hybrid optical-electrical automated testing equipment (ATE) system can implement an optical test assembly that includes an electrical interface and an optical interface with an optical-electrical device under test. The optical assembly can include a socket on which the device is placed by the ATE system to connect electrical and optical connections. The optical connections can couple light through the socket and the optical assembly to one or more testing devices to perform efficient testing of optical devices, such as high-speed optical transceivers.

Provided are an optical spectrum analyzer and a pulse-modulated light measurement method capable of measuring pulse-modulated light even when a pulse-on time and a pulse period of the pulse-modulated light are unknown. Pulse-modulated light (DUT) is incident on a diffraction grating 3. A first light receiving unit 8 receives the 0th-order light of diffracted light diffracted by the diffraction grating 3. A second light receiving unit 7 receives diffracted light of an order other than the 0th-order light. A measurement timing signal generation unit 9 generates a sampling signal based on the 0th-order light received by the first light receiving unit. The spectrum of the diffracted light received by the second light receiving unit is measured based on the sampling signal generated by the measurement timing signal generation unit.