NEC begins sale of single-fiber bi-directional optical transceiver

NEC Corporation has expanded its lineup of optical transceivers for 100Gb/s transmission, and has started selling the new “100G QSFP28 ZR4 BiDi,” which extends transmission distance to 80km, from today. This product is an improved version of the dual-fiber 100Gb/s transceiver that uses two fibers, and it achieves bi-directional data transmission in both the upstream and downstream directions using a single fiber.

In recent years, the spread of AI and video distribution services has led to an ever-increasing amount of data traffic, and demand for optical transceivers that connect data centers is expected to increase. At the same time, in response to the increase in data traffic, there is a continuous challenge to reduce the overall power consumption, latency, and cost of systems.

This optical transceiver achieves high-capacity communication over distances of up to 80 km using a direct detection method rather than a coherent method. It can also achieve bi-directional communication over a single fiber, making it possible to achieve low-power consumption, low-latency, low-cost direct connections between data centers. This contributes to lowering the power consumption, latency, and cost of the entire optical network system.

Features of the new product include the following:

1. Achieving cost efficiency
Conventionally, two fibers were required for 100Gb/s transmission, but this time, a compact filter has been developed that combines and separates the transmission and reception wavelengths, and bi-directional transmission has been achieved using a single fiber by wavelength multiplexing with different wavelengths for upstream and downstream. By reducing the number of fibers used, fiber procurement costs and rental costs can be reduced, enabling the construction of a cost-efficient network.

2. Achieving high-quality long-distance transmission
By incorporating a high-output laser on the transmitting side and an optical semiconductor amplifier on the receiving side, the required link budget of 30dB for 80km transmission is secured, enabling high-quality transmission. In addition, NEC also provides products that support not only the Ethernet signal rate (103Gb/s), but also the OTU4 signal rate (111.8Gb/s).

3. Connection with existing devices is possible
The electrical interface is the same as that of conventional 100G QSFP28 products, and it meets a specification of 5.5W or less power consumption, so it can be easily introduced into existing QSFP28 ports. In addition, because it uses a direct detection method, it achieves low latency and low cost compared to coherent methods.

Going forward, NEC will continue to provide optical transceivers incorporating advanced technologies such as its single-fiber bi-directional technology for both domestic and international markets.
BCS Bureau