Novel Route to Faster Fourier Transform Infrared Spectroscopic Imaging

Abstract

Fourier transform infrared (FT-IR) spectroscopic imaging microscopy couples a focal plane array (FPA) detector, integrated within an infrared microscope assembly, to an interferometer for attaining a multiplex/multichannel signal detection advantage. While this configuration should enable the acquisition of spatially resolved spectra over the entire field of view of a sample in the time that it takes a conventional FT-IR spectrometer to record a single spectrum, data acquisition in an imaging modality is an intrinsically slower process. We present a novel collection technique for step-scan, micro-imaging spectrometers that both allows large numbers of samples to be imaged rapidly and provides higher signal-to-noise ratios (SNRs) for given experimental time intervals. For example, data may be collected in as little as one minute, while SNRs greater than 800 are achieved for data acquired in less than 10 min. Imaging data acquired in the proposed, more rapid approach exhibit no loss in fidelity compared to data recorded by the conventional imaging techniques.