3.2 Coherent optical signal processing


The advent of complex modulation formats in the optical communications has enabled the almost 100% utilization of the capacity of the optical fiber. Polarization multiplexed QPSK transceivers are now commercially available for long haul transmission systems and M-QAM formats are considered for the new future in order to achieve the 400 Gb/s single wavelength target at 50 Gbaud. The receiver relies on the recent advancements in digital signal processing and A/D technologies developed for optical coherent detection. Although this solution is extremely powerful in handling linear impairments (chromatic and polarization dispersion, laser phase noise, etc) it is power greedy and still expensive due to the bottleneck of the electronics bandwidth. The possibility of utilizing optical signal processing for the complex modulation formats was revealed with the usage of phase sensitive amplification technology in optical fibers.

Our group in collaboration with other leading groups in Europe has demonstrated optical regeneration and optical phase quantization for M-PSK signals in the context of PHASORS project paving the way for coherent optical signal processing at the optical level. Moreover, relying on the limiting amplification properties of injection locked lasers, we demonstrated regenerative amplification of constant envelope phase modulated signals. Next target is to extend the basic principles for more complex modulation formats, such as M-QAM, elaborating photonic integrated solutions which support phase sensitive processes such as nanowaveguide in silicon-based materials.


Related projects:



Significant publications:

  • A. Bogris, D. Syvridis, “RZ-DPSK Signal Regeneration Based on Dual-Pump Phase-Sensitive Amplification in Fibers,” IEEE Photonics Technology Letters, vol. 18, pp. 2144-2146, Oct. 2006.
  • A. Fragkos, A. Bogris, D. Syvridis, “All-optical Regeneration Based on Phase-Sensitive Non-degenerate Four-Wave Mixing in Optical Fibers,” IEEE Photonics Technology Letters, vol. 22, pp. 1826-1828.
  • R. Slavík, F. Parmigiani, J. Kakande, C. Lundström, M. Sjödin, P. A. Andrekson, R. Weerasuriya, S. Sygletos, A. D. Ellis,L. Grüner-Nielsen, D. Jakobsen, S. Herstrøm, R. Phelan, J. O’Gorman, A. Bogris, D. Syvridis, S. Dasgupta, P. Petropoulos, and D. J. Richardson, “All-optical phase and amplitude regenerator for next generation telecommunications systems”,Nature Photonics, pp.690-695, 2010.
  • Joseph Kakande, Radan Slavík, Francesca Parmigiani, Adonis Bogris, Dimitris Syvridis, Lars Grüner-Nielsen, Richard Phelan, Periklis Petropoulos, David J. Richardson, “Multilevel quantization of optical phase in a novel coherent parametric mixer architecture,” Nature Photonics 5, 748–752, 2011.
  • A. Fragkos, A. Bogris, D. Syvridis, R. Phelan,"Amplitude Noise Limiting Amplifier for Phase Encoded Signals Using Injection Locking in Semiconductor Lasers", IEEE Journal of Lightwave Technology, Vol 30, NO.5, March 1, 2012.