Fig. 3.

Square wave reflectance results on a tissue phantom having known optical properties (${\mu }_a=0.0177$, ${\mu }_{\mathrm{s}}^{\prime }=1.0023{\mathrm{mm}}^{-1}$ at $659{\mathrm{mm}}^{-1}$). (a) A high-frequency ($0.28{\mathrm{mm}}^{-1}$) square wave appears sinusoidal as the light is reflected from the phantom (top). In this case, the DC (planar) and fundamental frequency from the pattern are extracted. (b) The light reflected from a low frequency ($0.06{\mathrm{mm}}^{-1}$) pattern contains harmonic components, which are extracted using MSE. The third harmonic component is corrupted by noise.