Thermal processes in red blood cells exposed to infrared laser tweezers (λ = 1064 nm)

Continuous-wave laser micro-beams are generally used as diagnostic tools in laser scanning microscopes or in the case of near-infrared (NIR) micro-beams, as optical traps for cell manipulation and force characterization. Because single beam traps are created with objectives of high numerical aperture, typical trapping intensities and photon flux densities are in the order of 10(6) W/cm(2) and 10(3) cm(-2) s(-1), respectively. The main idea of our theoretical study was to investigate the thermal reaction of RBCs irradiated by laser micro-beam. The study is supported by the fact that many experiments have been carried out with RBCs in laser NIR tweezers. In the present work it has been identified that the laser affects a RBC with a density of absorbed energy at approximately 10(7) J/cm(3), which causes a temperature rise in the cell of about 7-12 °C.