Scientists control the flow of heat and light in photonic crystals

May 8, 2015, University of Twente
Once the laser beam hits the surface of a sample it starts to generate heat which diffuses along the membrane but also it diffuses to the ambient gas. That effect reduces the width of the temperature distribution in the photonic crystal membrane.

Scientists from the MESA+ Institute for Nanotechnology at the University of Twente in the Netherlands and Thales Research & Technology, France, have found a way to control heat propagation in photonic nano-sized devices, which will be used for high speed communications and quantum information technologies. Their results are published in the leading American journal Applied Physics Letters on 30 April 2015.

Heat controls light

Photonic crystals, are photonic structures with nano-sized geometrical features, are useful for the light control, for example, they can be used to make ultra-compact for light. One of the simplest and most versatile ways to control these circuits is by heating them, thereby locally changing their properties. However, it is extremely important to apply at the right place, but this is difficult because heat tends to diffuse. As a consequence neighboring elements will be affected by the heat, producing unwanted changes in structures with multiple elements. However, heat propagation in thin membranes also depends on the surrounding media, thus providing an extra degree of freedom to control the heat distribution. 

Thus, the temperature distribution across the membrane can be reduced by changing the embedding medium. The faster the heat diffuses away, the narrower the temperature distribution is in the photonic crystal membrane.

The researchers experimentally and theoretically show that significantly better control is obtained using high thermal conductivity gases as the surrounding media. They found that when helium is used as the ambient gas, the width of the temperature distribution in the structure is reduced by 30% when compared to air. The results the researchers obtained are important because they enable thermal tuning of coupled resonators which will be valuable in the quest to build programmable optical circuits.

Explore further: Graphene meets heat waves

More information: Applied Physics Letters, Vol. 106, p. 171113 (2015)

Related Stories

Graphene meets heat waves

March 6, 2015

EPFL researchers have shed new light on the fundamental mechanisms of heat dissipation in graphene and other two-dimensional materials. They have shown that heat can propagate as a wave over very long distances. This is key ...

When temperature goes quantum

March 6, 2015

A UA-led collaboration of physicists and chemists has discovered that temperature behaves in strange and unexpected ways in graphene, a material that has scientists sizzling with excitement about its potential for new technological ...

Butterfly inspires new nanotechnology

September 2, 2013

By mimicking microscopic structures in the wings of a butterfly, an international research team has developed a device smaller than the width of a human hair that could make optical communication faster and more secure.

Recommended for you

Tracking hydrogen movement using subatomic particles

September 26, 2018

A muon is an unstable subatomic particle similar to an electron but with much greater mass. The lifetime of a muon is only a couple of microseconds, but this is long compared with the lifetimes of many unstable subatomic ...

Tumor cell expansion challenges current physics

September 26, 2018

A malignant tumor is characterized by the ability to spread. To do so, tumor cells stick to the surrounding tissue (mainly collagen) and use physical forces to propel themselves. A study published in Nature Physics by a team ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Graeme
not rated yet May 19, 2015
Hydrogen gas conducts heat even better.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.