  Depolarization of circularly polarized light scattered from biological
tissues depends on structural changes in cell nuclei, which can provide
valuable information for differentiating cancer tissues concealed in healthy
tissues. In this study, we experimentally verified the possibility of cancer
identification using scattering of circularly polarized light. We investigated
the polarization of light scattered from a sliced biological tissue with
various optical configurations. A significant difference between circular
polarizations of light scattered from cancerous and healthy tissues is
observed, which is sufficient to distinguish a cancerous region. The
line-scanning experiments along a region incorporating healthy and cancerous
parts indicate step-like behaviors in the degree of circular polarization
corresponding to the state of tissues, whether cancerous or normal. An oblique
and perpendicular incidence induces different resolutions for identifying
cancerous tissues, which indicates that the optical arrangement can be selected
according to the priority of resolution.
