Electro-optical imaging of electric fields in silicon sensors

TL;DR

This paper proposes a new electro-optical imaging method using the Franz-Keldysh effect to measure electric fields in silicon sensors with high accuracy, especially in radiation-damaged detectors under various conditions.

Contribution

It introduces a conceptual setup for measuring electric fields in silicon detectors via electro-optical imaging, leveraging the Franz-Keldysh effect, with estimated measurement accuracy.

Findings

Measurement accuracy of 1 to 4 kV/cm estimated.

Set-up applicable for radiation-damaged silicon detectors.

Can analyze effects of irradiation, temperature, and bias voltage.

Abstract

A conceptual set-up for measuring the electric field in silicon detectors by electro-optical imaging is proposed. It is based on the Franz-Keldysh effect which describes the electric field dependence of the absorption of light with an energy close to the silicon band gap. Using published data, a measurement accuracy of 1 to 4 kV/cm is estimated. The set-up is intended for determining the electric field in radiation-damaged silicon detectors as a function of irradiation fluence and particle type, temperature and bias voltage. The overall concept and the individual components of the set-up are presented.