Optimized configuration of the pyroelectric sensor metal electrodes in the photopyroelectric technique

Abstract

This article deals with the photopyroelectric (PPE) technique, a useful tool for optical spectroscopy and for measurement of thermal properties of condensed mater samples, in particular in the liquid state. It has been demonstrated here that, for constant laser power, the pyroelectric (PE) sensor response does not depend on the spatial distribution of the laser beam intensity. As a consequence of this, it follows that in the case of measurements in voltage mode, the signal amplitude is inversely proportional to the active area of the sensor. Then, if the active area is diminished, leaving the total area of the sensor constant, it is possible to increase the pyroelectric signal. On the basis of this result, a method is proposed to enhance the PPE signal measured in voltage mode by means of the optimization in the configuration of the sensor metal electrodes. It was experimentally demonstrated that using this improved technique, it is possible to increase up to ten times the amplitude of the signal without electrical noise rise.