Polarization Effects of Electro-Optic Sampling and Over-Rotation for High Field THz Detection

TL;DR

This paper presents a correction method for over-rotation in electro-optic terahertz sampling, enabling accurate detection of high-field terahertz signals without sacrificing sensitivity.

Contribution

It introduces a polarization-based correction technique that removes limits on measured terahertz field strengths in electro-optic sampling.

Findings

Over-rotation limits high-field detection accuracy.

Simultaneous polarization measurement corrects over-rotation.

Method preserves low-field sensitivity.

Abstract

With ever increasing availability of terahertz fields, it is important to find suitable detection techniques without compromising the measured dynamic range. Electro-optic terahertz sampling techniques, which are commonly used to detect terahertz fields, exhibit over-rotation at high fields that limit the detection accuracy. Here we discuss a method to correct for over-rotation that put no limits on measured terahertz field strengths, while preserving the low field sensitivity. We further evaluate the induced polarizations at high terahertz fields and show how over-rotation can be corrected by simultaneously measuring the polarizations before and after the quarter wave plate.