Coherent Electric Field Detection Methodology for Phase-Corrected Electro-Optic Sampling

Electro-optic (EO) sampling is a well-established technique for measuring electric fields, traditionally utilizing an EO crystal, quarter waveplate, Wollaston prism, and balanced photodetector. This article delves into the intricacies of EO sampling, highlighting the critical role of phase differences between the probe and generated electric fields. The frequency-dependence of these phase differences can significantly impact the EO signal, often leading to mitigated optical power differences. To address this, the article introduces a phase-correction element that introduces selected phase delays, ensuring a frequency-invariant phase difference and maximizing the EO signal. The developed numerical model evaluates these phase differences and demonstrates their correction using a ZnGeP2 EO crystal, both with and without a phase-correction crystal. This innovative approach paves the way for uncovering new EO sampling crystals and exploring novel applications in EO sampling, making it an essential read for those seeking to push the boundaries of this technology.