Statistical Analysis of 100 Gbps per Wavelength SWDM VCSEL-MMF Data Center Links on a Large Set of OM3 and OM4 Fibers

• Published in: Journal of lightwave technology Vol. 40; no. 4; pp. 1018 - 1026
• Main Authors: Torres-Ferrera, Pablo, Rizzelli, Giuseppe, Nespola, Antonino, Castro, Jose M., Kose, Bulent, Forghieri, Fabrizio, Gaudino, Roberto, Carena, Andrea
• Format: Journal Article
• Language: English
• Published: New York IEEE 15.02.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Bandwidth; Computer centers; Data centers; Digital signal processing (DSP); Equalizers; Error correction; Fibers; Links; Maximum likelihood estimation; Measuring instruments; multimode fibers; Optical fiber cables; Optical fiber devices; Optical fiber dispersion; Optical fiber LAN; PAM-4; Pulse measurements; Short wave radiation; shortwave wavelength division multiplexing (SWDM); Statistical analysis; Vertical cavity surface emission lasers; Vertical cavity surface emitting lasers; vertical cavity surface emitting lasers (VCSEL); Wavelength division multiplexing
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2021.3129455

We present a detailed statistical study on achievable reach of 100 Gbps data center optical links based on vertical cavity surface emitting lasers (VCSEL) and multimode fibers (MMF). Based on the characterization of the spectral and spatial properties of eight lasers and of the modal and dispersion behavior of a large set of 20233 OM3 and OM4 modeled fibers (obtained by properly extending an initial set of 500 measured fibers), we compute the resulting frequency responses of all of the VCSEL-MMF combinations. Then, we feed them to a numerical tool modeling PAM-4 transmission at 100 Gbps net bit rate per wavelength. Our model analyzes performance at distances up to 400 meters, using three different adaptive equalizers at the receiver and considering two forward error correction overheads. We show that 100 Gbps operation is feasible for 99% of the simulated links reaching up to 120 m over OM4 at 850 nm and using a decision feedback equalizer (DFE). Aggregated data rates of 200 Gbps and 400 Gbps per fiber using Shortwave Wavelength Division Multiplexing (SWDM) are achievable for 99% of the links reaching 80 m over OM4 using two wavelengths and feed-forward equalizer (FFE) and four wavelengths and maximum likelihood sequence estimation (MLSE)-based equalizer, respectively.