Design And Fabrication Of Linear Fresnel Zone Plates Used For Microspectrometer

Fresnel zone plate is a classic optical element that however can be used as the core spectral component of microspectrometer, which optical path volume can be decreased to 1mm(3). After passing through the Fresnel zone plate, monochromatic lights of different wavelengths will expand to spectrum because of their different focal length. We designed eight kinds of linear half zone plates to get different focal lengths and spectral performance. In the process of fabrication, we used the electron beam lithography and inductively coupled plasma(ICP) etching to produce the Fresnel zone plates. Finally, performances of Fresnel zone plates were examined by beam-split experiments. After comparison, the simulation conclusion in reference that the number of bands of Fresnel zone plates will affect the final appearance of the spectrum was verified.