Nonlinear Noise Measurement in Optical Links
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for measuring nonlinear damages in optical links suffer from significant deviations between measured and real nonlinear noise-to-power ratios, particularly due to limitations in band-notch width measurement accuracy and background noise interference.
Innovation Solution
A measurement apparatus and method that calculate multiple nonlinear noise-to-power ratios using band-notch signals with different widths, allowing for the extrapolation of a real nonlinear noise-to-power ratio corresponding to a band-notch width of zero, thereby enhancing measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a band-notch signal with a very narrow band-notch width is used to improve measurement accuracy, then the measurement result approaches the real nonlinear noise-to-power ratio, but the measurement accuracy is affected by background noises of the optical communication system and high spectrometer resolution is required
Solution Approach 1:
The patent changes the parameter of band-notch width by measuring multiple signals with different widths (e.g., 0.1nm, 0.05nm, 0.02nm) and then extrapolating to the theoretical zero-width case. This allows obtaining the real nonlinear noise-to-power ratio without actually using a zero-width notch, thus avoiding background noise interference while achieving high measurement precision.
2Measurement precision
If a band-notch signal with a very narrow band-notch width is used to improve measurement accuracy, then the measurement result approaches the real nonlinear noise-to-power ratio, but spectrometer resolution must be very high
Solution Approach 1:
The patent uses parameter changes by measuring multiple band-notch signals with progressively narrower widths that are still within the capability of existing spectrometers. By extrapolating these measurements to the zero-width case, the patent achieves high measurement precision without requiring ultra-high spectrometer resolution.
Solution Approach 2:
The patent performs preliminary measurements with multiple different band-notch widths to establish a trend or relationship. This preliminary action allows the system to extrapolate to the zero-width case, avoiding the need to directly measure with a zero-width notch which would require extremely high spectrometer resolution.
3Measurement precision
If a band-notch signal with a very narrow band-notch width is used, then the measurement result is closer to the real nonlinear noise-to-power ratio, but the measurement result still cannot accurately reflect the real nonlinear noise-to-power ratio
Solution Approach 1:
The patent systematically changes the band-notch width parameter across multiple measurements (e.g., 0.1nm, 0.05nm, 0.02nm) and uses the resulting data to extrapolate to the zero-width case. This mathematical extrapolation approach reliably determines the real nonlinear noise-to-power ratio, eliminating the inaccuracy that persists even with very narrow but non-zero bandwidths.
Data Source
AI summary
Embodiments of this disclosure provide a measurement apparatus and method for nonlinear damages in an optical link. The apparatus may include a processor to control execution of a process to generate multiple band-notch signals with different band-notch widths corresponding to a frequency point to be measured; and calculate respective multiple nonlinear noise-to-power ratios at the frequency point to be measured according to multiple band-notch signals obtained after the multiple band-notch signals with different band-notch widths pass through the optical link. A real nonlinear noise-to-power ratio may be extrapolated at the frequency point to be measured according to the multiple nonlinear noise-to-power ratios corresponding to the multiple band-notch signals with different band-notch widths.