Dynamic Characteristic Of Temperature Field In Bio-Cells Irradiated By Ultra-Fast Lasers

Recent advances in laser technology have made it possible to explore lasers with different pulse widths(from continoues wave to several femtosecond) to process with biological materials. Among these kinds of lasers, femtosecond lasers have extremely short pulse width (several femtosecond to hundreds of femtosecond) and highest peak power, the peak intensity of focused femtosecond laser is high to 10²⁰w/cm², such high peak power density is enough to ionize any materials. Femtosecond lasers show great promise because they can be used with any type of biological tissue, and they exhibit the highest precision and the least side-effect. The temperature field evolution caused by linear absorption during lasers processing with bio-materials had been studied by many scientists, the models they used are parallel lasers irradiating on bio-tissues with the shape of plane surface or cylinder, but actually scientists also using the lasers which transmit through high Numerical Aperture, then the lasers irradiate on spherical model bio-cells. About the topic of the optimum model and the temperature distribution in the cell under irradiating by ultrafast lasers, till now there is no detailed report. So in this article we take red blood cell (RBC) as research object, use related application software which is based on Maxwell's electromagnetic theory, irradiance distribution and dynamic phase distribution of lasers are simulationly studied. According to the dynamic phase distribution and linear absorption characteristics, we established the temperature distribution in the vicinity of the focal volume under; Then utilize numerical calculation and related software to calculate 2D temperature distribution in RBC, these results provides theoretical reference for further investigating the mechanisms of laser interaction with cells.This text divides into six parts: Chapter one introduced the background, history, current situation and the content, as well as the meaning of this paper; Chapter two studied the focused characteristic of femtosecond lasers in transparent materials; Chapter three analyzed the nonlinear mechanism of femtosecond laser process with bio-materials; Chapter four discussed the application of femtosecond laser interaction with bio-cells; Chapter five studied the temperature field caused by linear absorption in red blood cells irradiated by femtosecond pulse lasers; And Chapter six is the conclusion of this article and presented some other questions which need to be solved in future.