Homogenization and penetration effects of 1064 nm Nd:YAG solar laser and concentrated solar radiations on ex vivo chicken breast samples

To compare the penetration effect of both 1064 nm solar laser and concentrated solar radiations on biological tissue, ex vivo experiments were performed on chicken breast samples with similar incident doses. A 1064 nm Nd:YAG solar laser and a simple solar concentrator were first developed, both capable of emitting 10 W light power. Two square cross-section hollow light beam homogenizers were then designed and built, one emitting uniform monochromatic 1064 nm laser radiation and the other emitting uniform full-spectrum solar radiation, all within 24° divergence angle with about 5 W continuous-wave light power uniformly distributed in 0.36 cm2 homogenizer output area. For the same incident irradiance distribution and exposure time, and thus for similar incident dose, different light-tissue interaction effects were found. The 1064 nm solar laser radiation was less absorbed by the samples as compared to the solar radiation, resulting in a deeper 1064 nm laser radiation penetration in the tissue, revealing that wavelength was a crucial factor for light-tissue interaction research.