400G optical modules widely use PAM4 (4-level Pulse Amplitude Modulation) technology, which transmits signals through four different signal levels, with each symbol cycle representing 2 bits of logical information (0, 1, 2, 3). This technique allows signals to be transmitted at only half the symbol rate of NRZ signals, which greatly reduces the losses caused by the transmission channel. However, the signal-to-noise ratio can deteriorate much more than with NRZ signals and there are significant differences in measurement methods.

With the rapid development of data centres and high-speed networks, there is a growing demand for high-performance testing instruments for optical cats and optical modules. In this article, we will recommend several eye diagrams for 10G, 40G and 100G optical modules for R & D debugging and production testing, the recommended solutions are as follows: Optical Cat & Optical Module 10G/40G/100G NRZ&PAM4 Eye Diagram Test Equipment Recommendations

Optical communication is a technology that uses light waves as an information carrier to transmit information through a transmission medium such as an optical fibre. It works by converting the transmitted information (e.g. voice) into an electrical signal at the transmitting end and then modulating it onto the laser beam emitted by the laser, so that the intensity of the light varies according to the amplitude (frequency) of the electrical signal and is sent out through the optical fibre; at the receiving end, the detector receives the optical signal and converts it into an electrical signal, which is demodulated to restore the original information.

800G slowdown 400G rebound, optical module is the core component in the optical communication system, and its performance and cost directly affect the development of optical communication. With the increasing demand for high-speed, low-power and low-cost optical modules in 5G, data centres and other fields, the optical module industry is facing new challenges and opportunities.

Optical Module / Optical Cat Testing Solution is a solution to provide professional, efficient and reliable testing services for different types and specifications of optical modules. Optical Module Testing Customised Solution can design and implement suitable testing processes and methods according to customers' needs and standards, including performance testing, compatibility testing, stability testing, reliability testing of optical modules. The purpose of optical module testing customised solutions is to ensure the quality and performance of optical modules, to meet customer expectations and requirements, and to improve the market competitiveness of optical modules.

Currently, 100G Ethernet has become the dominant standard in data centres, but with the emergence of new technologies such as 5G, IoT and AI, 100G Ethernet can no longer meet future demands and 400G Ethernet has become the new target. To achieve higher bit rates at the same baud rate, it is necessary to use higher-order modulation, such as PAM-4 (Pulse Amplitude Modulation, 4th order) signalling, which carries two bits of information in each symbol to achieve twice the bit rate.

With the rapid development of the Internet, data centres and cloud computing have an increasingly high demand for network bandwidth. High-speed optical modules, as the core equipment for network transmission, have a direct impact on the performance and quality of network stability and efficiency. At present, 800G and 400G high-speed optical modules have become the mainstream choice for data centres and cloud computing, but how to effectively test these high-speed optical modules to ensure that they meet the relevant technical standards and application requirements is an urgent problem.