Active phase stabilization in Fourier-transform two-dimensional infrared spectroscopy

A scheme for active phase stabilization and absolute positioning in Fourier-transform two-dimensional (2D) IR spectroscopy is presented. The position accuracy is better than 20 nm(rms) corresponding to lambda/250 at 5 microm, which significantly improves the quality of Fourier-transform 2D IR spectra. Phase stabilization is added to a standard photon echo setup in a way that does not impair the flexibility of the experiment and the control over IR pulse parameters.