In this work we report the use of thermal lens (TLs) technique to determine the thermo-optical parameters, such as thermal conductivity ( K), thermal diffusivity (D) and the optical path dependence with temperature (ds/dT) of amorphous SiN. Our results indicate that ds/dT is positive at room temperature. Moreover, the obtained values of thermal diffusivity and thermal conductivity are in good agreement with that found in the literature. (c) 2008 Elsevier B. V. All rights reserved.