Linear and nonlinear optical effects in biophotonic structures using classical and nonclassical light.

In this perspective article, we review the optical study of different biophotonic geometries and biological structures using classical light in linear and nonlinear regime, especially highlighting the link between these morphologies and modern biomedical research. Additionally, the importance of nonlinear optical study in biological research, beyond traditional cell imaging is also highlighted and described. Finally, we present a short introduction regarding nonclassical light and describe the new future perspective of quantum optical study in biology, revealing the link between quantum realm and biological research.