Evaluation of Real-Time 8 × 56.25 Gb/s (400G) PAM-4 for Inter-Data Center Application Over 80 km of SSMF at 1550 nm

Abstract

Leveraging client optics based on intensity modulation and direct detection for point-to-point inter data center interconnect applications is a cost and power efficient solution, but challenging in terms of optical signal-to-noise ratio (OSNR) requirements and chromatic dispersion tolerance. In this paper, real-time 8x28.125 GBd dense wavelength division multiplexing (DWDM) PAM-4 transmission over up to 80 km standard single mode fiber (SSMF) in the C-Band is demonstrated. Using a combination of optical dispersion compensation and electronic equalization, results below a bit error rate (BER) of 1e-6 are achieved and indicate sufficient margin to transmit over even longer distances, if an FEC threshold of 3.8e-3 is assumed. Moreover, single channel 28.125 GBd PAM-4 is evaluated against optical effects such as optical bandwidth limitations, chromatic dispersion tolerance and optical amplified spontaneous emission (ASE) noise.

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

“…Following the MZM, a tunable optical bandpass filter (OBPF) with a 3-dB bandwidth of approximately 39 GHz is adopted and its output is amplified by a booster erbium-doped fiber amplifier (EDFA). The OBPF has a filtering profile very similar to a 50-GHz grid WDM MUX [23]. The OBPF is tuned to generate a frequency offset between the laser frequency and the MUX center frequency, leading to a VSB multi-band CAP signal [17][18][19].…”

56 Gbit/s OOK Signal in C-band Over 20 km Dispersion-Uncompensated Link Transmission With Receiver-Side EDC Algorithm

“…However, this method will not only increase cost but also cause significant attenuation. Furthermore, for compensating the loss, extra optical amplifiers may be required thus increasing the cost and reducing the optical signal-to-noise ratio of the system [4]. There exist other solutions for compensating CD, such as complex-valued singlesideband modulation [5], CD pre-compensation at the transmitter side [6] and Kramers-Kronig receiver [7].…”

Enhancement of Spectral Efficiency and Power Budget in WDN-PON Employing LDPC-Coded Probabilistic Shaping PAM8

“…The associate editor coordinating the review of this manuscript and approving it for publication was Qunbi Zhuge . pulse amplitude modulation (PAM4/8) signals are widely used in 200G/400G interface of optical signal transmission with direct detection [5]- [7]. Based on these superiorities, it is believed that the PAM modulation is a prospective candidate for future WDM-PON.…”