Design and measurement of a tunable resonant grating filter at oblique incidence

The aim is to use a resonant grating filter (RGF) in a tunable add-drop device. The tuning is achieved by placing the RGF on a tillable MEMS platform. The reflection peak wavelength shifts as a function of the angle of incidence. The filter works at oblique incidence since filter applications imply constant peak linewidth, and this also provides better beam separation. The measurements were performed with a HP8168 tunable laser source. Thus the experimental proof of the working principle of the resonant grating filter has been carried out.