Efficient Guided-Mode-Resonant Tunable Color Filters

Abstract

A new angle-tuned guided-mode resonance color filter is experimentally demonstrated. The device is designed using numerical methods and patterned using laser interferometric lithography. It consists of a 55-nm-deep silicon nitride and air diffraction grating with a 270-nm grating period along with a 110-nm-thick silicon nitride waveguide layer deposited on a glass substrate. The fabricated filter exhibits blue, green, and red color responses at incident angles of 8 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$^{\circ}$</tex> </formula> , 20 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$^{\circ}$</tex> </formula> , and 35 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$^{\circ}$</tex> </formula> , respectively. It has a bandwidth of 10 nm with efficiency near 90%.