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.

Passive optical network (PON) is a fibre-optic access technology that distributes fibre-optic signals to multiple users through a passive splitter, achieving the goal of fibre-to-the-home (FTTH).PON technology has the advantages of high transmission rate, wide coverage, low cost, energy saving and environmental protection, and it has become one of the mainstream technologies for broadband access. With the increasing demand of users for high-speed broadband access, PON technology is also developing continuously, from the initial GPON (Gigabit Passive Optical Network) and EPON (Ethernet Passive Optical Network), to the later 10G PON (10 Gigabit Passive Optical Network), and then to the latest 25G PON (25 Gigabit Passive Optical Network), the downlink rate of the PON technology has been increased by 25 times, reaching the level of 25Gbps. the level of 25 Gbps. This article will introduce the key technologies of 10G PON and 25G PON, as well as their advantages and application scenarios.

Optical communication is a technology that uses optical signals to transmit information in optical fibres or other media, which has the advantages of high transmission rate, large bandwidth and strong anti-interference. In order to evaluate the performance of optical communication system or optical module, some optical communication test parameters need to be measured and analysed, which include transmit optical power, receive sensitivity, extinction ratio, bit error rate, eye diagram and so on. This paper will briefly introduce the meaning, measurement method and analysis significance of these parameters.