J4 ›› 2018, Vol. 35 ›› Issue (5): 636-641.

• Fiber and Waveguide Optics • Previous Articles    

Angle-insensitive color filter based on sub-wavelength grating microstructure

GU Jiamei, ZHANG Siqi, ZHOU Hongyi, ZHENG Gaige   

  1. School of Physics and Optoelectronic Engineering, Nanjing University of Information Science and Technology, Nanjing 210044, China
  • Received:2017-07-06 Revised:2017-11-02 Published:2018-09-28 Online:2018-09-29

Abstract:

Based on the electromagnetic wave propagation and abnormal transmission characteristics of metal gratings in the visible light band (400 ~ 760 nm), a color filter composed of substrate, dielectric/metal composite structure and metal grating layer is designed and implemented. Influences of structural parameters on transmission spectrum are systematically analyzed by using effective medium theory (EMT) and rigorous coupled wave analysis (RCWA) method. Results show that the designed grating structure can effectively improve angle tolerance of the filter. The optimized structure parameters of red, green and blue (RGB) filters are obtained, and the spectral output with both high transmittance and angle insensitivity is obtained. The resonant wavelengths of the filters corresponding to red, green and blue are 705, 590, 452 nm, and the transmittance extremum reaches 66.4%, 81.24 and 81.23 respectively.

Key words: sub-wavelength optics; metallic gratings; color filters; rigorous coupled wave analysis