Revealing Carrier-Envelope Phase through Frequency Mixing and Interference in Frequency Resolved Optical Gating

TL;DR

This paper introduces ReD-FROG, a novel method for full temporal characterization of few-cycle pulses, including carrier-envelope phase retrieval, using interference in Frequency Resolved Optical Gating techniques, demonstrated both numerically and experimentally.

Contribution

The paper presents a new ReD-FROG framework that enables direct CEP measurement from FROG interference patterns, extending THz detection capabilities beyond bandwidth limits.

Findings

ReD-FROG accurately retrieves CEP of single-cycle THz pulses.

Numerical simulations confirm the effectiveness of the ReD-FROG scheme.

Experimental results demonstrate successful CEP measurement in THz pulses.

Abstract

We demonstrate that full temporal characterisation of few-cycle electromagnetic pulses, including retrieval of the carrier envelope phase (CEP), can be directly obtained from Frequency Resolved Optical Gating (FROG) techniques in which the interference between non-linear frequency mixing processes is resolved. We derive a framework for this scheme, defined Real Domain-FROG (ReD-FROG), as applied to the cases of interference between sum and difference frequency components and between fundamental and sum/difference frequency components. A successful numerical demonstration of ReD-FROG as applied to the case of a self-referenced measurement is provided. A proof-of-principle experiment is performed in which the CEP of a single-cycle THz pulse is accurately obtained and demonstrates the possibility for THz detection beyond the bandwidth limitations of electro-optic sampling.