Data centers where high-speed optical transmission technology is essential

The data center market has grown dramatically in recent years. In particular, the increasing bandwidth of data networks has led to faster and faster optical transceiver modules connecting devices in data centers.

In this article, we will introduce what an optical transceiver module is, for beginners who want to learn more about optical transceiver modules.

What is an optical transceiver module?

An optical transceiver module is a device that converts electrical signals into optical signals and vice versa, as shown in the diagram below.

Here we will explain what an "optical transceiver module" is, dividing it into the following five points.

1. Types of optical transceiver modules
2. Management interface to access optical transceiver modules
3. Optical fiber type
4. AOC: an integrated optical fiber and optical transceiver module
5. Relationship between standard and distance

1. Types of optical transceiver modules

The table below lists the optical transceiver modules that support each transmission speed.

SFP/QSFP are backward compatible. For example, in the case of an SFP28 cage, all SFPs (SFP, SFP+) can be inserted. Of course, a QSFP+ can be inserted into a QSFP28 cage, and QSFP28 and QSFP+ can also be inserted into a QSFP-DD cage. However, it is important to note that CFP is not compatible.

Product dimensions are regulated by form factor.

2. Interface to access the optical transceiver module

SFP/QSFP/QSFP-DD allows management of optical transceiver modules from the host side via the I2C interface. Specifically, it allows you to obtain various management information and control transmission and reception ON/OFF.

CFP/CFP2/CFP4/CFP8 use the MDIO interface.

3. Optical fiber type

There are two main types of optical fiber:

AOC (Active Optical Cable)

AOC is a combination of an optical transceiver module and an optical fiber cable, as shown in the photo below.

4. Relationship between standard and distance

The optical transceiver module has a set fiber and transmission distance for each optical communication standard (SR/LR, etc.). The table below summarizes the optical communication standard, fiber used, and transmission distance, and we hope it will be helpful for your selection.

Click here for information on testing methods for optical transceiver modules

What did you think. We also offer measuring equipment and evaluation jigs for measuring optical transceiver module systems.

If you would like to know more about what is needed for testing and how to troubleshoot network issues using measuring equipment, please see the article below.

What you need to test optical transceivers

Solving network problems using measuring instruments Part 1: Understanding the importance of interoperability testing

Resolving Network Problems Using Measuring Instruments Part 2 Performance Measurement of Optical Transceiver Modules

Optical Connector Types

There are four main types of optical connectors:

LC Connector

The LC connector is an optical connector used for a single optical fiber.

In the case of a Duplex LC connector, the optical fiber has two cores. LC connectors are widely used in 1G to 800G optical transceivers.

MPO Connector

MPO connectors are optical connectors used for multi-core optical fibers. There is a number after the letters MPO, which indicates the number of optical fiber cores. For example, MPO12 means that the number of optical fiber cores is 12.

Compared to LC connectors, this optical connector is characterized by its high density.

CS Connector

The CS connector, like the Duplex LC connector, is an optical connector used for two-core optical fibers. The CS connector is smaller in size than the Duplex LC connector, making it ideal for high density and integration.

SN Connector

The SN connector, like the LC connector and CS connector, is an optical connector used for two-core optical fibers. The SN connector is also smaller in size than the Duplex LC connector.

Below is a reference diagram showing the arrangement of duplex LC connectors, CS connectors, and SN connectors in the QSFP-DD form factor.

Compared to the duplex LC connector, the CS connector can connect two pairs, and the SN connector can connect four pairs, which shows that it is superior in terms of high density and integration.

Contact Us

the Company handle optical transceiver modules manufactured by Coherent. If you have any concerns about prices, delivery times, or product selection, please feel free to contact us.

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