Whispering galleries based technology may lead to nanolasers in future

January 24th, 2009 - 2:06 pm ICT by ANI  

Washington, Jan 24 (ANI): Scientists have created a plasmonic microcavity based on the phenomenon of whispering galleries, which could pave the way for nanolasers in the future.

The principle behind whispering galleries is that words spoken softly beneath a domed ceiling or in a vault can be clearly heard on the opposite side of the chamber.

Now, this knowledge has been used by the U.S. Department of Energys Lawrence Berkeley National Laboratory and the California Institute of Technology to achieve what could prove to be a significant breakthrough in the miniaturization of lasers.

They have developed a whispering gallery microcavity based on plasmons - electromagnetic waves that race across the surfaces of metals.

Such a plasmon wave has very small wavelength compared with the light, enabling the scaling down optical devices beyond diffraction limit of the light.

Cavities are the confined spaces in lasers where light amplification takes place and this new micro-sized metallic cavity for plasmons improves on the quality of current plasmonic cavities by better than an order of magnitude.

This plasmonic whispering gallery microcavity consists of a silica interior that is coated with a thin layer of silver.

It improves on the quality of current plasmonic microcavities by better than an order of magnitude and paves the way for plasmonic nanolasers.

We have shown for the first time that metallic microcavities based on surface plasmons can have a large quality factor and can thereby enable ultra-small device fabrication and strong enhancement of the light, said Xiang Zhang, a mechanical engineer who holds a joint appointment with Berkeley Labs Materials Sciences Division and the University of California (UC) Berkeley.

Plasmonic microcavities have uniquely different physical properties when compared to dielectric cavities and can extend microcavity research in entirely new ways, particularly at nanoscale dimensions, said Kerry Vahala, a physics professor at Cal Tech and authority on photonic devices.

Our work shows that the full potential of this new class of device can be realized with careful design and material control, Vahala added.

Ultrasmall lasers promise a wide variety of intriguing applications, including superfast communications and data handling (photonics), and optical microchips for instant and detailed chemical analyses. (ANI)

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