A gold–palladium thin-film microsensor array for thermal imaging of laser beam waists
Abstract
A new thermal microsensor, developed to control the position, focusing and 2D energy profile of laser beam waists is described. The sensitive area consists of a planar array of 16 individual thin-film gold–palladium thermocouple junctions (8×8 μm2), processed by means of standard integrated circuit technology (metallization on a glass substrate). The sensor thermoelectric response is determined; especially, the dynamic behaviour is characterized by measuring the time constant. Finally, thermal images and 2D beam energy profiles are obtained by scanning the sensor through Gaussian waists; a good agreement between the experimental results and the Gaussian beam theory is observed.