Nonlinear Transfer of Intense Few Cycle Terahertz Pulse Through Opaque n-doped Si

TL;DR

This paper investigates the nonlinear transmission of intense, few-cycle terahertz pulses through heavily n-doped silicon, revealing saturation and drop in transmission due to ionization effects and pulse reshaping.

Contribution

It demonstrates the nonlinear behavior and pulse transformation of intense terahertz radiation interacting with doped silicon, highlighting ionization-induced effects.

Findings

Transmission saturates at 8% for high fields

Transmission drops twofold at 20 MV/cm

Single-cycle terahertz pulse formation due to ionization

Abstract

Intense few cycle terahertz pulses exhibit complex non-linear behavior under interaction with heavily n-doped Si. Fast increase in the transmission of a 700 fs pulse (central frequency 1.5 THz) through the Si sample (low field transmission of 0:02 %) saturates at 8 % for the external field of 5 MV/cm and then drops twofold at 20 MV/cm. An electro-optical sampling measurements revealed formation of a single cycle terahertz pulse at this field due to formation of a thin ionized layer by the first intense oscillation of the terahertz field.