Demonstration of the First Real-Time End-to-End 40-Gb/s PAM-4 for Next-Generation Access Applications Using 10-Gb/s Transmitter

Multi-band CAP for Next-Generation Optical Access Networks Using 10-G Optics

“…In addition, the 5G Infrastructure Public Private Partnership (5G PPP) anticipates that 5G mobile networks need to accommodate a 1000-fold increase in data traffic thus low-cost mobile front-haul traffic will become one of the major drivers for PON data rates exceeding 10 Gb/s [3,4]. Focus is on low-cost solutions using advanced single carrier modulation schemes and demonstrations have been performed including chirp managed NRZ [5][6][7], electrical/optical Duobinary [8][9][10], and PAM-4 [8,11]. These schemes have shown the feasibility of supporting 25 Gb/s or 40 Gb/s data rate over typically 20-km SMF using 10-G transmitter [7][8][9][10][11] and/or 10-G receiver [7][8][9], thus are capable of offering low-cost solutions.…”

“…This is critcal for cost and power saving from operators' point of view. At high bit rates of 40 Gb/s/λ, however, the above-mentioned single carrier schemes with simple linear or nonlinear equalizations [10,11,13,14] are difficult to support transmission beyond 20-km SMF with reasonably high optical link power budgets unless dedicated dispersion compensation fibers (DCFs) [8,9] are adopted. The use of DCFs increases system cost and insertion loss, reduces system flexibility and complicates link configuration.…”

“…The transmitter contains an offline multi-band CAP signal generator, an 80-GS/s digital-to-analog convertor (DAC), a single-ended linear driver, and a 10-G tunable transmitter assembly (TTA). The TTA consists of a tunable laser (with 50-GHz WDM grid granularity) operating at 1543.3 nm and an InP dual drive Mach-Zehnder intensity modulator (MZM) with a bandwidth of around 13 GHz [11]. Although the TTA is more expensive than a 10-G directly modulated laser (DML) [5][6][7], it keeps a lower system operation and maintanence cost especially when DWDM is considered in green field deployments.…”

A 64 Gb/s PAM-4 Transimpedance Amplifier for Optical Links

“…Compared to the 64 Gb/s results from our previous contribution, [5], we were able to significantly improve the OMA sensitivity from 0 dBm to −7 dBm, as well as the dynamic range, with only a slight increase in power consumption from 165 mW to 180 mW. Other state-of-the-art publications detailing PAM-4 BER measurements at similar bit rates report a higher TIA power consumption [7], [8] or no power consumption at all [9]. Real-time 60 Gb/s BER measurements are presented in [8], achieving a BER=10 −3 sensitivity for an average optical input power of −1.3 dBm using a commercial TIA that consumes 1200 mW.…”

“…Real-time 60 Gb/s BER measurements are presented in [8], achieving a BER=10 −3 sensitivity for an average optical input power of −1.3 dBm using a commercial TIA that consumes 1200 mW. [7] and [9] present more complex experiments for which the TIA plays only a small role; their BER results are achieved using power-hungry digital signal processing techniques such as a feedforward equalizer and a decision-feedback equalizer. Furthermore, one of [7]'s results is achieved using an avalanche photodiode, whereas [9] used an Erbium-doped optical fiber amplifier with 25 dB gain in front of the photodiode to significantly boost the received input power.…”