Tunable spatial demultiplexer based on the Fabry-Perot filter.

Superprism effect is exhibited in one-dimensional thin film stacks due to their abnormal dispersion and anisotropy properties near the bandgap. Thin film Fabry-Perot filter (FPF) was designed and fabricated to realize this effect. Furthermore, the polychromatic light was operated at different incident angles onto the device to get more demultiplexing channels at different wavelength range. This means FPF, which fabricated low-costly and simply can be used as a tunable demultiplexing device. Meanwhile, distinguished with other researchers' arithmetic, transfer matrix method (TMM) with the Gaussian angular spectrum method was introduced to calculate more accurate spatial shift at different wavelength as well as to analysis beam splitting phenomena in FPF.