Ultrafast spectroscopy
Two-dimensional infrared spectroscopy
A nonlinear infrared spectroscopy technique investigating vibrational modes in condensed-phase systems.
Introduction
What is 2DIR?
Two-dimensional infrared spectroscopy (2DIR) is a nonlinear infrared technique for vibrational modes in condensed-phase systems. Spreading the vibrational information along multiple axes yields a frequency-correlation spectrum: vibrational mode coupling, and chemical and molecular dynamics, with femtosecond resolution.
Why use two frequency axes
The same strengths listed for 2D electronic spectroscopy apply: uncoupled time and excitation-frequency resolution, background-free detection, and a wide excitation-frequency window in a single run. 2DIR became practical with ultrafast lasers such as CARBIDE and PHAROS and with femtosecond infrared pulses from a broadband mid-infrared source such as ORPHEUS-MIR. The visible analogue is two-dimensional electronic spectroscopy (2DES).
