Virtual optical experiments. Part I. Modeling the measurement process.
In recent years, internal laser probing techniques that exploit the electro-optical and the thermo-optical effects have been introduced. Space-resolved and time-resolved measurements of charge-carrier and temperature distributions in the interior of semiconductor samples have thus become possible. For a profound analysis and the optimization of these measurement techniques, a physically rigorous model for simulating the entire measurement process is presented. The model includes the electrothermal device simulation of the sample's operating condition, the calculation of the resulting refractive-index modulations, the simulation of wave propagation through the device under test, the imaging lenses and aperture holes, and the simulation of the detector response. As an essential part of this model, a numerically efficient algorithm for simulating wave propagation in large computational domains has been developed. The decisive step is introduction of a suitably chosen set of computational variables that allows a significantly coarser discretization width without loss of accuracy.