Patent application number | Description | Published |
20090147244 | Method and apparatus for measuring the birefringence autocorrelation length in optical fibers - Disclosed is a method and apparatus for determining the birefringence autocorrelation length of a fiber in a non-destructive manner. The PMD of an optical fiber is measured over a first optical spectrum. A Faraday rotation angle is measured over a second optical spectrum. The birefringence autocorrelation length is determined from the measuring of the PMD and the Faraday rotation angle. | 06-11-2009 |
20100123896 | Method and Apparatus for Measuring the Birefringence Autocorrelation Length in Optical Fibers - Disclosed is a method and apparatus for determining the birefringence autocorrelation length of a fiber in a non-destructive manner. The PMD of an optical fiber is measured over a first optical spectrum. A Faraday rotation angle is measured over a second optical spectrum. The birefringence autocorrelation length is determined from the measuring of the PMD and the Faraday rotation angle.) | 05-20-2010 |
20100134788 | Method for Increasing Accuracy of Measurement of Mean Polarization Mode Dispersion - The present invention provides a method of determining a mean differential group delay associated with a length of optical fiber. The method including measuring a magnitude of a polarization mode dispersion vector as a function of frequency, using a frequency-domain polarization mode dispersion measurement apparatus, where the magnitude of the polarization mode dispersion vector is a scalar differential group delay. Also the method calculates a frequency derivative of the scalar differential group delay from the magnitude of the polarization mode dispersion vector to obtain a first result. The frequency derivative of the scalar differential group delay being a scalar second-order polarization mode dispersion function. The method further multiplies a proportionality coefficient B | 06-03-2010 |
20110051126 | Method for Increasing Accuracy of Measurement of Mean Polarization Mode Dispersion - A method of determining a mean square differential group delay associated with a length of optical fiber. The method including measuring a polarization mode dispersion vector as a function of frequency, using a frequency-domain polarization mode dispersion measurement apparatus. The method also including calculating a second-order polarization mode dispersion vector as a function of frequency by calculating a derivative of the polarization mode dispersion vector with respect to frequency. Also, calculating the mean of the magnitude of the second-order polarization mode dispersion vector to obtain a first result. Further, multiplying a proportionality coefficient by the first result to calculate the mean square differential group delay. | 03-03-2011 |
20110109954 | Method and Apparatus for Generating 8-QAM-Modulated Optical Signal - A system and method for producing an 8-QAM-modulated signal are disclosed. The methodology, in an exemplary expedient, generally comprises splitting light from a CW laser into two parts; modulating the first part with a first signal and modulating the second part with a second signal; phase shifting the modulated second part by about π/4; combining the modulated first part with the phase shifted and modulated second part to produce a four-level modulated signal; and phase modulating the four-level modulated signal with a third signal with a phase modulation of (0, π/2). Several variations of this method are described herein. | 05-12-2011 |
20110129215 | Method and Apparatus for Broadband Mitigation of Polarization Mode Dispersion - Described is a method and system for reducing system penalty from polarization mode dispersion. The method includes receiving a plurality of signals at a receiving end of a transmission line, each signal being received on one of a plurality of channels of the transmission line and measuring a signal degradation of at least one of the channels of the transmission line. An amount of adjustment of a polarization controller is determined based on the signal degradation, the amount of adjustment being selected to reduce the polarization mode dispersion. The amount of adjustment is then transmitted to the polarization controller. | 06-02-2011 |
20130136452 | Time-Domain Based Composite Modulation for Spectrally Efficient Optical Networks - Methods, systems, and apparatuses for time-based composite modulation of an optical carrier signal are provided. Time-based composite modulation includes determining a plurality of fixed time slots for the optical carrier signal, wherein the plurality of fixed time slots comprise a time-division-multiplexing frame. Determining a modulation format for each fixed time slot of the time-division-multiplexing frame, wherein a transport spectral efficiency of the modulation format determined for a first fixed time slot is different from a transport spectral efficiency of the modulation format determined for a second fixed time slot, and determining a number of binary bits for each fixed time slot of the time-division-multiplexing frame, wherein the number of binary bits for a fixed time slot is based on the modulation format determined for the fixed time slot. | 05-30-2013 |
20150326338 | Time-Domain Based Composite Modulation for Spectrally Efficient Optical Networks - Methods, systems, and apparatuses for time-based composite modulation of an optical carrier signal are provided. Time-based composite modulation includes determining a plurality of fixed time slots for the optical carrier signal, wherein the plurality of fixed time slots comprise a time-division-multiplexing frame. Determining a modulation format for each fixed time slot of the time-division-multiplexing frame, wherein a transport spectral efficiency of the modulation format determined for a first fixed time slot is different from a transport spectral efficiency of the modulation format determined for a second fixed time slot, and determining a number of binary bits for each fixed time slot of the time-division-multiplexing frame, wherein the number of binary bits for a fixed time slot is based on the modulation format determined for the fixed time slot. | 11-12-2015 |