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| Title | Optically linearized modulators: chirp control for low-distortion analog transmission |
| Publication Type | Journal Article |
| Year of Publication | 1997 |
| Authors | Jackson, M. K., V. M. Smith, W. J. Hallam, and J. C. Maycock |
| Journal | Lightwave Technology, Journal of |
| Volume | 15 |
| Pagination | 1538 -1545 |
| Date Published | aug. |
| ISSN | 0733-8724 |
| Keywords | 300 km, 50 km, 80-channel North American frequency plan, analog transmission systems, cable television, chirp control, chirp modulation, composite-second-order distortion, CSO-limited range, first-principles model, increasing fiber length, linearity, low-distortion analog transmission, modulator chirp parameter, modulator design, optical fibre subscriber loops, optical fibre theory, optical modulation, optical noise, optically linearized Mach-Zehnder modulators, optically linearized modulators, optimized low-chirp modulator, standard single-mode fiber, system CSO calculations |
| Abstract | We show that an increase of composite-second-order (CSO) distortion with increasing fiber length can occur in analog transmission systems using optically linearized Mach-Zehnder modulators and that the degradation is due to generation of chirp in the modulator. We extend a first-principles model to calculate the modulator chirp parameter and show that system CSO calculations using this model are in excellent agreement with measured results. Finally we propose and demonstrate a novel modulator design where chirp is greatly reduced while preserving excellent linearity. For an 80-channel North American frequency plan an optimized low-chirp modulator is predicted to extend the CSO-limited range of the system over standard single-mode fiber from approximately 50 km to greater than 300 km |
| URL | http://dx.doi.org/10.1109/50.618387 |
| DOI | 10.1109/50.618387 |