Infrared Spectroscopy with Visible Light

We present a novel infrared spectroscopy technique, which uses well-developed and low-cost optical components designed for operation in the visible range. The method is based on nonlinear interference of entangled photons generated via spontaneous parametric down conversion. We further advance the technique by developing a data processing algorithm, which eliminates the need for a spectral selection device, which results in the increase of the signal to noise ratio and processing speed.