New color filter enables smaller and more economical displays

A University of Michigan professor has invented a new color filter technology. Through nanoscale slits, pixels of every imaginable color can be produced from white background light.

The new color filter consists of two very thin metal layers, with a dielectric layer in between, in which narrow slots have been cut. The white background light is collected by the fine grid, after which the grid emits light with a specific frequency through resonance.

According to Jay Guo, a professor in the Department of Electrical Engineering and Computer Science at the University of Michigan, by varying the distances between the slots, you can basically produce any color. For example, red light is formed by placing the slits 360 nanometers apart.

The pixels of the new display technology are about eight times smaller than those of iPhone 4 LCD, according to Guo. This makes the technology especially interesting for use in projectors or, for example, head-mounted displays.

According to Guo, the new color filter is cheaper to produce than LCDs, because it consists of only three layers. LCDs are constructed from two layers of polarization, a color filter and two glass plates with the electrodes on top. Guo’s new color filter makes a polarization layer unnecessary. The light output of the pixels is also much higher than with an LCD.

To demonstrate the technology, Guo and his research team built the University of Michigan logo at a size of 12 by 9 micrometers using the new color filter.