Measurement of optical penetration depth and refractive index of human tissue

Experimental techniques for measurement of optical penetration depth and refractive index of humantissue are presented, respectively. Optical penetration depth can be obtained from the measurement ofthe relative fluence-depth distribution inside the target tissue. The depth of normal and carcinomatoushuman lung tissues irradiated with the wavelengths of 406.7, 632.8 and 674.4 nm in vitro are respectivelydetermined.In addition,a novel simple method based on total internal reflection for measuring therefractive index of biotissue in vivo is developed,and the refractive indices of skin from people of differentage, sex and skin color are measured.Their refractive indices are almost same and the average is 1.533.