This study proposes a novel computational technique for specific energy loss for pulse incidence. Our method is based on a fast inverse Laplace transform (FILT) with an electromagnetic field solver in the complex frequency domain. Using the FILT algorithm, the specific energy loss in the complex frequency domain can be computed and transformed into the time domain. In our method, the specific energy loss can be computed until the desired observation time without solving the electromagnetic field at the previous observation time. The finite-difference complex-frequency domain (FDCFD) was used for the complex frequency domain solver. The results demonstrated that our proposed method could compute the dissipated energy of inhomogeneous, non-dispersive lossy dielectrics.