Infrared photography in liquid films by thermocapillary convection

A thermal imaging system using a liquid-liquid interface has been studied, which utilizes the extreme temperature sensitivity of surface tension (Marangoni Effect). Theoretical considerations for the design and the operating conditions of the device are given. The experimental results using a detection by polarization interferometer indicate that the limitations on such a device are primarily due to the finite film thickness of the upper solution (on the order of 50–80 m). This system was able to image 1°C with a limiting resolution of ten lines pair per millimeter.