Efficient room temperature polariton laser could advance intrachip and interchip optical interconnects

University of Michigan researchers have demonstrated a new, practical and potentially more efficient way to make a coherent laser-like beam using polaritons. This is the first room-temperature electrically pumped polariton laser (other electrically pumped polariton lasers typically operate at cryogenic temperatures).

This is most real-world ready polariton lasers ever developed. It represents a milestone like none the field has seen since the invention of the most common type of laser – the semiconductor diode – in the early 1960s, the researchers say. While the first lasers were made in the 1950s, it wasn’t until the semiconductor version, fueled by electricity rather than light, that the technology took off.

This work 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.

The researchers didn’t develop it with a specific use in mind. They point out that when conventional lasers were introduced, no one envisioned how ubiquitous they would become. Today they’re used in the fiber-optic communication that makes the Internet and cable television possible. They are also in DVD players, eye surgery tools, robotics sensors and defense technologies, for example.

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.

Laser Focus World – The device is gallium arsenide (GaN)-based. The work could advance intrachip and interchip optical interconnects (the lasers can potentially be integrated into semiconductor-based photonic chips), and may also have applications in medical devices and treatments.

A polariton is a quasiparticle consisting of a combination of a photon and an exciton (which itself is an electron-hole pair). Polariton lasers harness these particles to emit light; they are predicted to be more energy efficient than traditional lasers. The new prototype requires 1000 times less electricity to operate than its conventional counterpart made of the same material. The beam emitted by the device is ultraviolet and very low power (less than a microwatt).

The paper, “Room Temperature Electrically Injected Polariton Laser,” will be published online in Physical Review Letters on June 10, 2014.

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