Design and fabrication of microstructure narrowband filter

In order to improve transmittance of microstructure narrowband filters and increase precision of microstructure unit, new fabrication method of film deposition and microstructure unit are proposed in this paper. Three different center wavelength filters are design based on concepts of Fabry-Perot principle. Three different center wavelength of narrowband filters are fabricated by combining photochemical mask separation and PECVD technology. Center wavelength of narrowband filters are λ₁=480 nm、λ₂=520 nm and λ₃=590 nm respectively, transmittance are all above 80%, with bandwidth between 30 nm to 50 nm and an area for each microstructure unit 50×50 μm². Transmittance is improved, while precision of microstructure unit are increased to reach micron order effectively with neat edge and clear dividing line.