Measuring the deposited energy from a non-ionizing laser beam in water by digital holographic interferometry

Digital Holographic interferometry is a powerful and widely used optical technique for accurate measurement of variations in physical quantities such as density, refractive index, and etc. In this study, an experimental digital holographic interferometry setup was designed and used to measure the amount of energy changes induced by absorption of radiation from a non-ionizing infrared laser beam in a water cell. An effective theoretical method is used to measure the absorption dose, which is based on tracing of the interference pattern displacement due to changes in the energy content of the adsorbent material. It is shown that the results of the interferometric method are in good agreement with the results obtained from the measurement with a precise temperature sensor. Experimental results show the capability of this optical method for non-contact and non-intrusive monitoring of the changes in the amount of absorbed energy by non-ionizing laser radiation in material.