Note: Comparison between a prism-based and an acousto-optic tunable filter-based spectrometer for diffusive media

This paper compares two continuously tunable systems for time-resolved spectroscopy of diffusive media based on a supercontinuum laser source. Two approaches for spectral selection are considered relying either on a dispersive prism or on a commercial acoustic-optic tunable filter (AOTF) device. The comparison was performed first in terms of extracted power and spectral response function, then in terms of distortions introduced in the retrieved absorption and scattering spectra. Simulations and experiments on diffusive phantoms confirmed that, besides narrower FWHM in the AOTF bandpass, the prism solution is superior with respect to the distortions produced on the recovered spectra.