The Modal Effect of VCSELs on Transmitting Data Rate Over Distance in OM4 Fiber

• Published in: IEEE journal of quantum electronics Vol. 56; no. 6; pp. 1 - 6
• Main Authors: Wang, Hsiao-Lun, Qiu, Junyi, Yu, Xin, Fu, Wenning, Feng, Milton
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.12.2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adaptive optics; Cavity resonators; Data centers; Data transmission; Emission analysis; Equalization; microwave photonics; optical fiber communication; Optical fibers; optical interconnects; Temperature measurement; VCSELs; Vertical cavity surface emitting lasers
• ISSN: 0018-9197; 1558-1713
• DOI: 10.1109/JQE.2020.3022360

The effective modal bandwidth (EMB) limit for the multi-mode (MM) VCSEL on transmitting data rate over distance in OM4 fiber is commonly referenced to be within 4700 MHz*km. However, this limit may not be valid for the VCSELs with reduced-mode (RM) or single-mode (SM) emission spectrum for data transmission. In this work, we investigate the EMB limit of OM4 fiber through characterizing three types of 850 nm oxide-VCSELs, namely, MM, RM and SM. Each type of VCSEL is tested to the highest error-free NRZ data rate over transmitting distance up to 1 km. The MM VCSEL demonstrates 50 Gb/s (100 m) and 26 Gb/s (300 m) that are within EMB limit. In contrast, the RM and SM VCSELs demonstrate speed distance product beyond the OM4 EMB limit. The SM VCSEL delivers record speed-distance of 44 Gb/s (500 m), and 36 Gb/s (1 km) at 25 °C without the use of equalization. These results suggest the SM VCSEL-based MMF link can transmit much higher data rate over extended distance up to 2 km in data centers.