A simulation framework is developed for the two-dimensional finite-difference time-domain to model multilayer photonic crystal structures. The framework includes the recording process in a photosensitive material through a coherent light source and then a subsequent interrogation with a broadband spectrum. Moreover, the tunable response of the photonic crystal is simulated for different film thicknesses (recorded from 5 to 20 μm), refractive indices contrast (ranging from 4% to 24%), film expansions (interrogated with expansions ranging 110% to 160%), and lattice spacings (recorded with wavelengths from 360 to 560 nm). A parallelization method was implemented in a computer cluster to alleviate the required high computational demand. Through this simulation framework, it is now possible to retrieve relevant information about realistic photosensitive multilayer structures. This method will support the design of multilayer structures utilized in sensors, lasers, and other functional nanostructured photonic devices.