In the process of digitization, data processing, storage and transmission have developed rapidly. The rapid growth of a large number of data search services and video services has led to the development of data centers based on supercomputers and storage. As the main product for short-distance data center interconnection applications, high-speed parallel transmission optical modules have broad market application prospects. In this article, ETU-LINK will introduce the 40G QSFP+ and 100G QSFP28 parallel optical modules applied in data centers.

Parallel optical modules are arranged to drive arrays, lasers, detectors, and MCU chips. Signal transmission and reception can be completed through multiple channels, which enables parallel optical communication to support higher rates. Because of this, parallel optical communication needs to use multiple optical fibers to support higher rate transmission, so multi-core connector MPO is needed to support higher data transmission rate.

The parallel optical module uses VCSEL (Vertical Cavity Surface Emitting Laser) as the light source. Compared with edge-emitting semiconductor lasers, VCSEL can concentrate the output of light and couple the energy into the fiber efficiently. Moreover, VCSEL can be mass-produced and cut into pieces after testing. A separate device, thereby reducing the cost of the laser.

1. 40G QSFP+ SR4

The 40G SR4 optical module adopts a 4-channel 850nm VCSEL array and a PIN photodetector array, and makes eight optical fibers into four duplex channels, each channel supports 10G Ethernet transmission, making the transmission rate up to 40Gbps.

The 40G QSFP+ SR4 optical module conforms to the QSFP+ MSA and IEEE 802.3ba 40GBASE-SR4 Ethernet standards, and the transmission distance through OM3/OM4 MM fiber can reach up to 100m or 150m.

2. 100G QSFP28 SR4

100G SR4 Optical Module with CDR, 4-channel 850nm VCSEL Laser Array and PIN photodetector array, Compliant with QSFP28 MSA and IEEE 802.3bm 100GBASE-SR4 Ethernet Standard, Compatible with IEEE 802.3ba 40GBASE-SR4 Ethernet and InfiniBand FDR/EDR Standard, the transmission distance through OM3/OM4 MM fiber can reach up to 70m/100m.

Parallel optical modules need to be used with MPO fiber adapters. 40G/100G SR4 is usually used with 12-core multi-mode MPO fiber patch cords. The application of parallel optical modules and MPO technology continues to develop, which can support higher-speed optical transmission, and many wiring And network experts pointed out that parallel optical modules and MPO technology can be well applied for 40/100G Ethernet transmission at present, providing a good transmission environment for 40/100G Ethernet transmission.