Abstract
In today's high-bit-rate WDM systems, it is essential to monitor the residual chromatic dispersion (CD) to ensure that it does not exceed the designed tolerance. Among the schemes for CD monitoring reported so far, inband subcarrier tone method is relatively simple and effective for CD monitoring. However, this technique may be influenced by both polarization mode dispersion (PMD) and the chirp fluctuation of the external modulator. In this paper, we investigate the effect of PMD and chirp on CD monitoring and show that the presence of PMD and chirp induces significant CD monitoring errors. To tackle this problem, we propose a CD monitoring technique to suppress the influence caused by PMD and chirp fluctuation. In the proposed CD monitoring scheme, two RF tones are added at the transmitter. The light is coupled into an apriori known dispersion offset and then split into two branches in the monitoring module. A fiber Bragg grating filter which can remove one sideband is inserted before the photodetector of one branch. The PMD effect is eliminated by optically sideband filtering and RF power ratio detection, and the monitoring error induced by the small chirp fluctuation can be suppressed using two RF tones and a dispersion offset. The operational principle is analyzed and the experimental investigation is presented. Experimental results show that this technique can accurately monitor the accumulated CD without being affected by the PMD and small chirp fluctuation.
Original language | English |
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Article number | 602106 |
Journal | Proceedings of SPIE - The International Society for Optical Engineering |
Volume | 6021 I |
DOIs | |
Publication status | Published - 1 Dec 2005 |
Externally published | Yes |
Event | Optical Transmission, Switching, and Subsystems III - Shanghai, China Duration: 7 Nov 2005 → 10 Nov 2005 |
Keywords
- Chirp
- Chromatic dispersion
- Optical performance monitoring
- Pilot tone
- Polarization mode dispersion
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Computer Science Applications
- Applied Mathematics
- Electrical and Electronic Engineering