Printed Lasers

Scientists have created printed lasers using ordinary inkjet printers - a move that could lead to an easier and cheaper way to make future laser devices.

Via BBC:

A University of Cambridge team has used liquid crystals in place of ink to print tiny dots on a surface covered with a special coating.
Once the coating dries, the dots become lasers, the researchers wrote in the journal Soft Matter ...

"Until now, no one has been able to print lasers; the materials typically used to make lasers only work on certain surfaces and after extensive, and expensive, manufacturing processes," Damian Gardiner of Cambridge University, one of the team members, told the BBC.
"A laser requires three things to work: a cavity, or space between two mirrors so light can bounce back and forth, a 'gain' medium to increase the amount of light, and energy.
"Our laser uses the special optical properties of the LC to get rid of the mirrors, and a dye is added to give gain.
"However, the key thing is that it is a liquid system - and can therefore be inkjet-printed, very inexpensively."

"The lasers can be used for various display and lighting applications, or they can encode information and turn any surface into a 'smart surface'.