GBT20, a 20.48 Gbps PAM4 Optical Transmitter Module for Particle Physics Experiments

TL;DR

The paper introduces GBT20, a radiation-tolerant, high-speed PAM4 optical transmitter module designed for particle physics experiments, featuring compact size, low power consumption, and robust performance under radiation exposure.

Contribution

It presents a novel 20 Gbps PAM4 optical transmitter module with radiation tolerance, compact design, and integrated optical interfaces for particle physics applications.

Findings

Achieves 20.48 Gbps data rate with low TDECQ of 0.7 dB.

Maintains performance after 5.4 kGy radiation dose.

Consumes approximately 164 mW power in low-power mode.

Abstract

We present a pluggable radiation-tolerant 4-level Pulse-Amplitude-Modulation (PAM4) optical transmitter module called GBT20 (Giga-Bit Transmitter at 20 Gbps) for particle-physics experiments. GBT20 has an OSFP or firefly connector to input 16-bit data each at 1.28 Gbps. The GBT20 drives a VCSEL die with an LC lens or a VCSEL TOSA and interfaces an optical fiber with a standard LC connector. The minimum module, including the host connector, occupies 41 mm x 13 mm x 6 mm. At 20.48 Gbps, the minimum Transmitter Dispersion Eye Closure Quaternary (TDECQ) is around 0.7 dB. The power consumption is around 164 mW in the low-power mode. The SEE cross-section is below 7.5x10^(-14) cm^2. No significant performance degrades after a TID of 5.4 kGy.