Narrow Optical Filtering Tolerance of 127-Gb/s DP-QPSK Utilizing Real-Time DSP with 20 Cascaded 50-GHz Filters in the Presence of 40,200-ps/nm Chromatic Dispersion
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Narrow Optical Filtering Tolerance of 127-Gb/s DP-QPSK Utilizing Real-Time DSP with 20 Cascaded 50-GHz Filters in the Presence of 40,200-ps/nm Chromatic Dispersion
- Author:
Suhas Bhandare, Zhenxing Wang, Kyu Kim, Mark Colyar, Heider Ereifej
In this paper, we experimentally investigated the tolerance to narrow optical filtering using a real-time state of the art DSP designed into an OIF-compliant module. We show that a real-time DSP is very resilient to tight optical filtering even in the presence of exceptionally large amount of chromatic dispersion and center frequency offsets. The ever increasing demand for higher network capacity and greater spectral efficiency is forcing system vendors to upgrade the channel data rates to 100-Gb/s over 50 GHz spaced frequency grids. The dual polarization quadrature phase shift keying (DP-QPSK) modulation format with coherent detection and baseband digital signal processing (DSP) using high-speed analog-to-digital converters (ADCs) have emerged as a standard in the form of optical internetworking forum (OIF) implementation agreement for 100-Gb/s single-carrier long-haul transport.
