High-speed detection of ballistic photons propagating through suspensions using spectral interferometry

I describe spectral interferometry (SI) with incoherent radiation to detect ballistic photons propagating through suspensions. SI detects mutual interference between a sampling beam and a reference beam, even in cases where the former is not equal to the latter in regard to propagation delay time. I have succeeded in eliminating virtual images by performing three spectral measurements with three different reference beam phases. By removing virtual images, the observed dynamic range is increased by 20 db. SI has potential for improving the image-obtaining time of optical computed tomography. In my experiment, a one-line scan time of 200 μs has been achieved.