|EXFO INC. Patent applications|
|Patent application number||Title||Published|
|20130088718||MULTIPLE-ACQUISITION OTDR METHOD AND DEVICE - An OTDR device and method for characterizing one or more events in an optical fiber link are provided. A plurality of light acquisitions is performed. For each light acquisition, test light pulses are propagated in the optical fiber link and the corresponding return light signals from the optical fiber link are detected. The light acquisitions are performed under different acquisition conditions, for example using different pulsewidths or wavelengths. Parameters characterizing the event are derived using the detected return signal from at least two of the plurality of light acquisitions.||04-11-2013|
|20120201533||Reference-Based In-Band OSNR Measurement on Polarization-Multiplexed Signals - There is provided a method for determining an in-band noise parameter, such as the Optical Signal-to-Noise Ratio (OSNR), on an optical signal-under-test (SUT) propagating along an optical communication link and comprising a data-carrying signal contribution of any arbitrary degree of polarization and a noise contribution. A spectral shape trace of signal contribution in the SUT is estimated using a reference optical spectrum trace of a reference signal which comprises a signal contribution that is spectrally representative of the signal contribution of the SUT and a noise contribution which is at least approximately known. The signal contribution is mathematically discriminated from said noise contribution in the SUT using the spectral shape trace and the test optical spectrum trace. The in-band noise parameter is then determined at least from the mathematically discriminated noise contribution.||08-09-2012|
|20120134667||All-Optical, Phase Sensitive Optical Signal Sampling - An optical sampling arrangement for high-speed measurement of the time-varying electric field of an optical input signal utilizes coherent mixing of the optical input signal with a reference laser source in a phase-diverse optical hybrid solution, followed by optical sampling of the coherently-mixed fields at the output of the optical hybrid. The generated streams of optical samples are then detected and signal processed in order to reconstruct a sampled version of the electric field of the original optical input signal.||05-31-2012|
|20120093501||In-Band Optical Noise Measurement Using Differential Polarization Response - A method comprises: acquiring, for a number nSOP of varied State-Of-Polarization analysis conditions of the input optical signal, nSOP polarization-analyzed optical spectrum traces, the distribution of the input optical signal of said SOP analysis conditions being approximately known; mathematically discriminating said signal contribution from said noise contribution within said optical signal bandwidth using said polarization-analyzed optical spectrum traces, said mathematically discriminating comprising: obtaining a differential polarization response that is related to the optical spectrum of said signal contribution by a constant of proportionality; estimating the constant of proportionality of a differential polarization response to the optical spectrum of said signal contribution as a function of said number nSOP; estimating the optical spectrum of said noise contribution from said input optical signal, within said optical signal bandwidth using said constant of proportionality and said differential polarization response; and determining said in-band noise parameter on said input optical signal from the mathematically discriminated noise contribution.||04-19-2012|
|20110182573||All-Optical Balanced Detection System - A two-gate sampling system has been designed to perform sampled balanced detection of one or more input signal pairs. The present invention performs simultaneous sampling of both signals in each signal pair followed by digitization and combination of the sample pairs using software. By first sampling the signals and then combining the sampled into the corresponding balanced detected signal it is possible to avoid the bandwidth limitations and impedance problems introduced by traditional balanced detectors and electrical oscilloscopes. In particular, for optical sampling gates very high bandwidth sampling gates can be designed without any impedance issues and hence almost perfect balanced detection reconstruction can be performed for very high speed signals. Balanced detection is becoming more and more important as the new phase modulated optical data signals are introduced to the market, such as e.g. PSK, DPSK, QPSK and DQPSK. The present invention is well suited for analysis of these new types of signals.||07-28-2011|
Patent applications by EXFO INC.