Optical tomography in industry is used as a sensor of thickness and internal structure of semiconductors.

Soft tissues are highly scattering but weakly absorbing in the near-infrared and red parts of the spectrum, so that this is the wavelength range usually used.

[4] This concept has been used in several academic and commercial systems for breast cancer imaging and cerebral measurement.

The key to separation of absorption from scatter is the use of either time-resolved or frequency domain data which is then matched with a diffusion theory based estimate of how the light propagated through the tissue.

The measurement of time of flight or frequency domain phase shift is essential to allow separation of absorption from scatter with reasonable accuracy.