| EXFO INC. Patent applications |
| Patent application number | Title | Published |
|---|
| 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 |
