Tunable Optical Filter Based on Two Thermal Sensitive Layers

In this letter, a tunable filter design based on polymer and silicon layers is presented. It is shown that by taking advantage of the different thermal properties of these materials, the overall spectral and tuning characteristics can be controlled by selecting the thickness of these layers. Moreover, a mathematical model to simulate the reflectivity spectrum and the tuning behavior due to the temperature of the filter is presented. Finally, two filters were fabricated and their experimental behavior is well described by our mathematical approximation model.