Study of the Radiation Hardness of Vcsel and Pin Arrays

TL;DR

This study evaluates the radiation tolerance of VCSEL and PIN optical arrays used in particle physics detectors, finding that silicon PIN arrays are suitable for the Super LHC environment, while GaAs PIN arrays are not.

Contribution

It provides experimental data on the radiation hardness of various VCSEL and PIN arrays, informing their suitability for high-radiation environments like the SLHC.

Findings

Silicon PIN arrays remain operational after irradiation at SLHC doses.

GaAs PIN arrays show significantly reduced responsivity post-irradiation.

VCSEL arrays can operate up to SLHC radiation levels.

Abstract

The silicon trackers of the ATLAS experiment at LHC (CERN) use optical links for data transmission. VCSEL arrays operating at 850 nm are used to transmit optical signals while PIN arrays are used to convert the optical signals into electrical signals. We investigate the feasibility of using the devices at the Super LHC (SLHC). We irradiated VCSEL and GaAs PIN arrays from three vendors and silicon PIN arrays from one vendor. All arrays can be operated up to the SLHC dosage except the GaAs PIN arrays which have very low responsivities after irradiation and hence are probably not suitable for the SLHC application.