Colour filter could enable higher-definition displays

The filter might eventually enable higher-definition display screens to be made more efficient, smaller and at a higher definition.

The gratings, sliced into metal-dielectric-metal stacks, act as resonators that trap and transmit light of a particular colour, or wavelength, said Jay Guo, associate professor in the Department of Electrical Engineering and Computer Science. Simply by changing the space between the slits, different colours can be generated.

His team used this technique to make what they believe is the smallest colour logo of the university. At about 12 x 9 microns, it is about one-sixth the width of a human hair.

Conventional liquid-crystal displays are inefficient and manufacturing-intensive to produce. Only about five per cent of their back-light travels through them. They contain two layers of polarisers, a colour filter sheet and two layers of electrode-laced glass in addition to a liquid-crystal layer. Chemical colourants for red, green and blue pixel components must be patterned in different regions on the screen in separate steps.