Temperature control of water-based substances by CO2 laser for medical applications.

Temperature of water-based substances is investigated by aiming a pulsed CO(2) laser beam at the water-air surface. This method of controlling temperature is believed to be flexible in medical applications as it avoids the use of thermal devices, which are often cumbersome and generate rather larger temperature swing with time. The control of temperature in this laser method is modeled by the heat conduction equation. In this investigation, it is assumed that the energy delivered by the CO(2) laser is confined within a very thin surface layer of roughly 10 μm. It is shown that the temperature can be very well controlled by a CO(2) laser at a steady temperature, and we demonstrate that the method can be adapted to work in tandem with another laser beam.