Studies of VCSEL Failures in the Optical Readout Systems of the ATLAS Silicon Trackers and Liquid Argon Calorimeters

TL;DR

This paper investigates early failures of VCSELs used in ATLAS detector readout systems, analyzing failure mechanisms and environmental factors affecting device longevity.

Contribution

It provides a detailed failure analysis of VCSELs in high-energy physics experiments, highlighting environmental impacts on device lifetime.

Findings

VCSEL failures occur prematurely compared to expected lifetime

Failure mechanisms are influenced by environmental conditions

Insights can improve future VCSEL reliability in detector systems

Abstract

The readout systems for the ATLAS silicon trackers and liquid argon calorimeters utilize vertical-cavity surface-emitting laser diodes to communicate between on and off detector readout components. A number of these VCSEL devices have failed well before their expected lifetime. We summarize the failure history and present what has been learned thus far about failure mechanisms and the dependence of the lifetime on environmental conditions.