CD-insensitive PMD monitoring based on RF power measurement

Abstract

Abstract:We propose and experimentally demonstrate a chromatic dispersion (CD)-insensitive first-order polarization mode dispersion (PMD) monitoring method based on radio-frequency (RF) power measurement. In high-speed (>10-GSym/s) transmission systems, a narrowband fiber Bragg grating (FBG) notch filter filters out the optical components at 10GHz away from the carrier. After square-law detection, the 10-GHz RF tone changes with PMD and is insensitive to CD, which can be used as a PMD monitoring signal. Compared with the monitoring techniques utilizing clock tone, the PMD measurement range is increased from 26.3-ps to 50-ps while the requirement of the bandwidth of photodetector is reduced from 19GHz to 10GHz in 19-Gsym/s systems. It is experimentally shown that this technique is efficient on CD-insensitive first-order PMD monitoring for 38-Gbit/s DQPSK and 57-Gbit/s D8PSK systems.

A PMD-tolerant CD estimation algorithm for FTN coherent optical transmission systems

“…In order to study the effect of CD on the order of training sequences, the simulation conditions are set to 64GBaud FTN PM-16QAM, with an acceleration factor of 0.85, a cumulative CD amount of 15360ps/nm, a center frequency of 193.1THz, a frequency offset of 1.5GHz, and a line width of 100kHz. The center frequency shifts of the two training sequences TS1 and TS2 are 193.1THz-15GHz and 193.1THz+15GHz, respectively, with a training sequence length of 2 12 . Under the above conditions, the transformation order of the DC signal FrFT is verified from [-0.2,0.2].…”

“…A method for blind PMD estimation using tap coefficients in equalizers 11 was proposed in 2009, however, this method requires estimating PMD after equalization, which may result in poor estimation results due to insufficient tap numbers. A method of measuring radio frequency (RF) power by placing notch filters to complete PMD estimation 12 has been proposed in 2011, this method can achieve both CD and PMD estimation, but RF power varies with OSNR. Since it is difficult for FTN systems to tolerate large CD estimation errors, it is of great significance to study a PMD-tolerant CD estimation algorithms applicable to FTN systems.…”

Simultaneous Monitoring of CD and OSNR Based on Delay-Tap Sampling and Image Processing

“…The square of mean value and variation of the top or right edge are calculated to represent the signal and noise power level. Then the OSNR can be calculated by equation ( 1) and (2).…”

“…Optical performance monitoring (OPM) is an important function in high speed and dynamic reconfigurable optical network systems. Many OPM techniques have been proposed to monitor a single optical transmission system parameter such as optical signal-to-noise ratio (OSNR), chromatic dispersion (CD) and polarization mode dispersion (PMD) [1][2][3]. Since the performance of an optical communication system is often decided by a combination of system parameters, it is essential that a technique can be developed to monitor more than one parameter simultaneously.…”

BER Performance of PDM 4-QAM Optical Transmission System Considering the Effects of PMD and GVD Using Exact Probability Density Function

“…Ever increasing data rates, temperature changes, power variations and changes in stresses induce birefringence causing GVD and PMD values of the optical fiber to the levels that exceed the system tolerances [1][2]. The impacts of PMD and GVD in SMF are of great interests in current and next generation high speed optical data transmission systems [3,4].…”