Laser Gets Some Bling

A team of physicists at Macquarie University in Sydney has built the first diamond laser using a technique based on the Raman effect. The research could lead to new laser sources that operate over a wide range of wavelengths and with very high power levels.

Macquarie University physicist Richard Mildren works with a CVD diamond. (Image: Macquarie University)

Virtually indestructible, diamonds can transmit heat and light very effectively, creating the potential for very powerful lasers and making them of extreme interest to scientists. Their excellent optical properties have long been known, and there have been significant efforts around the globe to demonstrate diamond (diode) lasers for more than 15 years.

One big drawback to using natural diamonds is their high price tag. The Macquarie team led by Richard Mildren overcame that obstacle by creating its own affordable diamonds through chemical vapor deposition processes.

"Using natural diamonds in this type of work is problematic -- the quality is not consistent and, as everybody knows, they're very expensive," Mildren said. "In the last two to three years the production method has really ramped up -- diamonds can now be grown using a method called chemical vapor deposition and a one-centimeter-long crystal can be purchased for around $2000 [AUD]."

In building the diamond laser, Mildren's team demonstrated a new, more effective method for generating a powerful beam and that CVD diamonds are of adequate size and quality to enable exploration of a new class of laser devices.

"This research could pave the way for new laser sources over a wide range of wavelengths and with very high power levels," Mildren said.

Diamond laser. (Image: Richard Mildren)

"The next step is to see how effectively CVD diamond lasers operate at even higher power levels. We'd also like to investigate the potential for diamond Raman lasers in the ultraviolet and longwave infrared regions where other materials can't operate."

If his future experiments are again successful, Mildren said there was potential for diamond Raman lasers to be used in everything from terahertz threat detection (eg. body scanning devices at airports) and ultrahigh precision laser surgery, to defense applications such as directed-energy weapons.

For more information, visit: www.mq.edu.au