Dynamic visible interferometric measurement of thermal fields around living biological objects

Dynamic interferometry is a highly sensitive means of obtaining phase information that can determine phase at rates of a few measurements per second. The sensitivity of these phase-measurement instruments is on the order of thousandths of a wavelength at visible wavelengths enabling the measurement of small temperature changes and thermal fields surrounding living biological objects. Temperature differences are clearly noticeable using a visible wavelength source because of subtle changes in the refractive index of air due to thermal variations between an object and the ambient room temperature. Living objects can also easily be measured over a period of time to monitor changes as a function of time. This technique has many promising applications in biological and medical sciences for studying thermal fields around living objects. In this paper we compare differences in thermal fields measured with dynamic phase-measuring interferometry surrounding room temperature and body temperature inanimate objects as well as living biological objects at data rates of many measurements per second.