Printable Lasers Developed

By Ron Grunsby, Editor

Researchers at the University of Cambridge have developed a process that can print high-resolution multi-color laser arrays on almost any surface, rigid or flexible, potentially using everyday printing and publishing equipment. The process can be applied to produce compact, tunable laser sources; high-resolution laser displays; and fluorescence tag-based “lab-on-a-chip” arrays used in biology and medicine. Since it will be possible to print these lasers almost anywhere, potential applications will increase.

The lasers are based on chiral nematic liquid crystals (LCs), which are like the materials used in flat-panel LCD displays. The LC molecules have a helix-shaped structure that can function as an optically resonant cavity if they are aligned the right way. The cavity can be optically excited to produce laser light after a fluorescent dye is added.

The researchers used a custom inkjet printing system to print hundreds of small dots of LC materials onto a substrate that was covered with a layer of wet polymer solution. Chemical interaction and mechanical stress as the solution dried caused the LC molecules to align and turn each printed dot into a laser.

The UK Engineering and Physical Sciences Research Council funded the project, which was a joint effort of the Centre for Molecular Materials for Photonics and Electronics and the Inkjet Research Centre. Both centers are in the Department of Engineering at the University of Cambridge. A patent application has been filed in the UK.

Additional information is available from the University of Cambridge, and the full article can be read in the journal Soft Matter.