Abstract
SIGNIFICANCE: Understanding thermal effects on tissue optical properties is fundamental for optimizing laser-based medical interventions. We address the critical knowledge gap of temperature-dependent changes in porcine dermis optical properties. AIM: We explore the thermal damage influence on the excised dermis optical properties at wavelengths from 400 to 1100 nm. APPROACH: Using a double-integrating-sphere system and inverse adding-doubling, we determined absorption, μa , and reduced scattering, μs' , coefficients before and after a 2.5-min thermal exposure. RESULTS: We observed non-linear changes in both μa and μs' across temperature regimes. Minimal changes occurred at 37°C and 43°C. At 50°C, slight increases in both coefficients were observed. Significant alterations occurred at 60°C, with substantial increases in μs' and variable changes in μa depending on wavelength region. At 70°C, μs' values remained elevated, whereas μa showed mixed responses, with some wavelength regions decreasing, indicating progressive structural breakdown. The Arrhenius damage model showed an exponential increase with temperature. CONCLUSIONS: We reveal complex thermal-induced changes in tissue optical properties, particularly at higher temperatures. Findings reinforce a critical threshold between 50°C and 60°C where significant changes occur. The non-linear, wavelength-dependent responses emphasize the need for comprehensive data in laser-tissue interaction modeling, with important implications for optimizing laser-based medical treatments.