Department of Electronic and Information Engineering

A team of researchers led by Professor Din-Ping Tsai, Chair Professor and Head of PolyU’s Department of Electronic and Information Engineering, have developed a chip that promises to unlock the full potential of quantum computing. The chip is based on a series of miniature “meta-lenses” composed of nano antennae for capturing photons from a laser beam and focusing them on the same point.

The antennae are placed on a surface made of gallium nitride, a semiconductor material known for its excellent optical quality. Each antenna measures 45 x 80 x 800 nanometres. More than 250,000 of these tiny antennae went into the composition of one lens, which measures 100 microns in diameter, about the size of a human hair. To demonstrate how their approach works, the team designed and fabricated an optical chip with an array of 10 x 10 lenses to polarise incoming light.

Dr Chen Mu-ku, Research Assistant Professor of Department of Electronic and Information Engineering, said it is like making tea with a teabag. A laser beam going through a conventional lens is like making many cups of tea with one single teabag, the more the cups, the lighter the tea. On the other hand, the meta-lenses are making 100 cups of tea with 100 teabags at the same time, therefore both the colour and the speed would not be compromised.

The chip may help quantum information science realise many applications in our daily life in the future, such as enhancing the security in online transactions. 

The research result was published by one of the world’s top scientific journals, Science. The team is also awarded the Areas of Excellence Scheme funding of HK$65 million recently by the Research Grants Council. The story of this research project which covered by Ta Kung Pao are available at the following websites: