Designing the performance of a thick-film laser power detector by means of a heat-transfer analysis using finite-element method

摘要

Besides the usual application of thick-film technology to produce circuits of high reliability, this technology is also attractive for the fabrication of sensors, A laser power detector has been realized utilizing the thick-film technique. A special detector configuration provides an exact laser power measurement independent of the position of beam impingement on the detector area and independent of the intensity distrbution of the laser beam. The detector, which actually operates as a heat-flow meter, consists of a thermopile circularly applied on an AIN substrate. The geometrical proportions of the detector have been accommodated to an NdYAG laser with a given specification by means of thermal heat-transfer analysis using the finite-element method (FEM). Based on the FEM simulation of steady state and transient temperature distributions on the detector area induced by laser beam impingement, the performance and the operating range of the detector have been specified.