In the process of data center evolution to 400G/800G, Single Lambda 100G Transmission has become a key breakthrough point to reduce the complexity of optical networks. ETU-LINK 100G QSFP28 Dual-fiber LR1 optical module redefines the energy efficiency boundary of high-speed optical interconnection by deeply integrating PAM4 Modulation Technology with single lambda long-distance transmission.

I. Technical Foundation: How Does PAM4 Achieve Single Lambda 100G Transmission?

PAM4 (4-Level Pulse Amplitude Modulation) is an encoding technology that transmits 2-bit data through 4 different voltage levels (corresponding to 00/01/10/11). Compared with the traditional NRZ (Non-Return-to-Zero) 2-level (0/1, 1 bit per symbol), PAM4 doubles the data throughput at the same baud rate.

Previously, 100G optical modules almost all used NRZ modulation. The combination of PAM4 technology and Single-Lambda 100G ensures the stability and reliability of data transmission .

II. PAM4 Technology Implementation of LR1 Module: Full-link Collaborative Design

1. Transmitter: Adopt electro-absorption modulated laser (EML), generate 4-level optical signal through PAM4 driver chip, and use pre-emphasis technology to compensate high-frequency loss to ensure signal integrity.

2. Receiver: [ Adaptive equalization filter ] dynamically eliminates inter-symbol interference (ISI) caused by fiber dispersion; [ Strong FEC (KP4) error correction ] solves the disadvantage of PAM4 in noise resistance; [ Clock data recovery (CDR) ] extracts full-rate clock to suppress signal jitter .

3. It strictly complies with IEEE 802.3cu and 100G Lambda MSA standards, and can replace the traditional 4-wavelength LR4 solution, significantly reducing the deployment complexity and cost of scenarios such as data center interconnection and 5G fronthaul.

Today, as single-channel 100G becomes mainstream, Single-Lambda optical modules have successfully solved the triple dilemma of high-speed optical communications, namely, "multiple wavelengths, high cost, and high power consumption", through deep optimization of PAM4 technology, full-link signal enhancement, and extreme power consumption control.