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日本語

“The experimental evidence provided in this study advances this research field toward the realization of actively controllable integrated micro lasers,” said Taichi Goto, second author of the paper and an assistant professor in the Department of Electrical and Electronic Information Engineering at Toyohashi University of Technology.

Other study contributors include scientists from the Institute for Molecular Science at the Laser Research Centre in Japan and the Electrical and Computer Engineering Department at Iowa State University in the United States.

Q switch lasers are used in a variety of applications, including in surgical procedures, and can produce more precise results with less damage than traditional tools. The lasers require integration of active and passive responsibilities for maximum efficiency.

"There are two advantages to actively controlling integrated micro lasers," said Goto. “Firstly the small size of the lasers allows for the use of mass production techniques. Secondly, the price of each Q switch laser can be lowered thanks to the integration.”

A technique called Q switching produces short but high-powered pulse outputs. As in other lasers, an electric current excites electrons in a laser medium − in this case, it’s a crystal used in solid-state lasers − and emits the resulting energy as amplified light. The light can be polarized in one direction or another, but it’s nearly impossible to change the randomly polarized light in a small Q switch laser.

Goto and his team used Q switching, along with a laser a tenth of the size of one cent, to produce a laser beam ten times more powerful than previously reported with larger lasers.

Along with the change of laser size, the researchers also adjusted the magnetic material through which the light travels and amplifies to a more powerful pulse. With the addition of a neodymium-yttrium-aluminum-garnet, Goto could use magneto-optics to better control how the light moves within the laser cavity.

The short pulses allow the researchers to change the polarization of the laser through manipulation of the photons comprising the light. Instead of a constant light, each pulse can be switched. The laser size means the energy punches out, instead of dissipating as it travels inside the system.

The researchers plan to increase the peak power of their system, according to Goto. They also plan to apply the system as an integrated micro laser for further testing.