Using precarious particles called polaritons that straddle the worlds of light and matter, University of Michigan, Ann Arbor, researchers have demonstrated a new, practical and potentially more efficient way to make a coherent laser-like beam. They say that their first-time polariton laser is fueled by electrical current as opposed to light, and works at room temperature, rather than way below zero.

Those attributes, they say, make the device the most real-world ready of the handful of polariton lasers ever developed. This could advance efforts to put lasers on computer circuits to replace wire connections, leading to smaller and more powerful electronics. It may also have applications in medical devices and treatments and more.

A polariton is part light and part matter. Polariton lasers harness these particles to emit light. They are predicted to be more energy efficient than traditional lasers. The new prototype requires 250 times less electricity to operate than its conventional counterpart made of the same material.

The design the team used helped them achieve the beam with an electrical rather than light input signal. Getting the electrical current into the system requires electrodes sandwiching the gallium nitride and several layers of mirrors to render the electrical signal useable. Other groups' approaches put the electrodes outside the mirrors. They said it was tough to get the signal strong enough under those circumstances. So they deconstructed the “sandwich” and put the mirrors on the sides of the gallium nitride and left the electrodes on the top and bottom.

Their research was published online in Physical Review Letters yesterday.

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