Femtosecond Temporal Phase-Resolved Nonlinear Optical Spectroscopy in Molecules with Lock-in Enabled Phase Tracking

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Pandey, Siddhant, Walz, Francis, Shivaram, Niranjan
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866909531677655040
author Pandey, Siddhant
Walz, Francis
Shivaram, Niranjan
author_facet Pandey, Siddhant
Walz, Francis
Shivaram, Niranjan
contents We describe an experiment to measure the emitted real-time electric field from an ultrafast third-order nonlinear optical interaction in molecules, using a phase-tracked spectral interferometry scheme. By combining a software lock-in amplification based spectrometer with spectral interferometry, we measure the electric field of the nonlinear optical signal from rotationally excited gas-phase molecules. The lock-in spectrometer allows selective measurement of signals of interest with improved signal-to-noise ratio, while rejecting any unwanted incoherent background. The nonlinear optical signal interferes with a known reference pulse on the spectrometer, which allows measurement of ultraweak signal electric fields. Further, we show that lock-in detection enables correction of slow interferometric drifts by utilizing a multidimensional measurement space. Thus, interferometric stability is achieved without the need for active stabilization, which typically utilizes an independent phase drift measurement. We present data from an experiment in impulsively aligned molecules that demonstrates the important features of our scheme. The scheme can be applied to study ultrafast dynamics in laser excited systems in the gas, liquid, and solid phases of matter.
format Preprint
id arxiv_https___arxiv_org_abs_2503_05986
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Femtosecond Temporal Phase-Resolved Nonlinear Optical Spectroscopy in Molecules with Lock-in Enabled Phase Tracking
Pandey, Siddhant
Walz, Francis
Shivaram, Niranjan
Optics
Chemical Physics
Quantum Physics
We describe an experiment to measure the emitted real-time electric field from an ultrafast third-order nonlinear optical interaction in molecules, using a phase-tracked spectral interferometry scheme. By combining a software lock-in amplification based spectrometer with spectral interferometry, we measure the electric field of the nonlinear optical signal from rotationally excited gas-phase molecules. The lock-in spectrometer allows selective measurement of signals of interest with improved signal-to-noise ratio, while rejecting any unwanted incoherent background. The nonlinear optical signal interferes with a known reference pulse on the spectrometer, which allows measurement of ultraweak signal electric fields. Further, we show that lock-in detection enables correction of slow interferometric drifts by utilizing a multidimensional measurement space. Thus, interferometric stability is achieved without the need for active stabilization, which typically utilizes an independent phase drift measurement. We present data from an experiment in impulsively aligned molecules that demonstrates the important features of our scheme. The scheme can be applied to study ultrafast dynamics in laser excited systems in the gas, liquid, and solid phases of matter.
title Femtosecond Temporal Phase-Resolved Nonlinear Optical Spectroscopy in Molecules with Lock-in Enabled Phase Tracking
topic Optics
Chemical Physics
Quantum Physics
url https://arxiv.org/abs/2503.05986