We propose to use the rare-earth-doped silica as the IR-to-visible converter. Its principle of operation employs the up-conversion on pumping with the near-IR radiation. A time-dependent 3-D heat transfer model for fiber geometry, incorporating the finite element method appropriate to the fiber geometry, is developed to perform the resolution analysis. The simulation results of the study demonstrate the spatial and temporal resolution of this transducer for the constant and impulse irradiation profile, confirming the concept feasibility. The performance in terms of temporal and spatial resolution is appreciably improved when the Er-doped silica fiber is in contact with a cold reservoir. The cold sink also enhances the speed of device response, as the latent image is quickly erased. © 2003 Society of Photo-Optical Instrumentation Engineers.