On Chip Metamaterial with a Refractive Index of Zero

[jackwynne]

TLDR: New on chip metamaterial allows for light to be better manipulated at the nanoscale and in a way that could be integrated into further photonic applications

 

Sources:

https://www.seas.harvard.edu/news/2015/10/to-infinity-and-beyond

http://www.nature.com/nphoton/journal/vaop/ncurrent/full/nphoton.2015.198.html

 

The refractive index of a material is essentially how quickly the phase of a wave changes in a material. A vacuum has a refractive index of 1 (with air being close to one), water has a refractive index of about 1.3 (this causes the light to bend when it moves between the water and air causing) and diamond has a refractive index of about 2.4 (which causes the sparkles of well-cut diamond).

 

A new metamaterial has been developed in a Harvard lab that has a refractive index of zero, which allows for light to be manipulated at the nanoscale.

Having a refractive index of zero essentially means that instead of looking like a usual wave with troughs and crests the light becomes one infinitely long crest or trough.

 

According to the Harvard article

This uniform phase allows the light to be stretched or squished, twisted or turned, without losing energy. A zero-index material that fits on a chip could have exciting applications, especially in the world of quantum computing. 

 

“Integrated photonic circuits are hampered by weak and inefficient optical energy confinement in standard silicon waveguides,” said Yang Li, a postdoctoral fellow in the Mazur Group and first author on the paper. “This zero-index metamaterial offers a solution for the confinement of electromagnetic energy in different waveguide configurations because its high internal phase velocity produces full transmission, regardless of how the material is configured.”

and

“In quantum optics, the lack of phase advance would allow quantum emitters in a zero-index cavity or waveguide to emit photons which are always in phase with one another,” said Philip Munoz, a graduate student in the Mazur lab and co-author on the paper.  “It could also improve entanglement between quantum bits, as incoming waves of light are effectively spread out and infinitely long, enabling even distant particles to be entangled.”

 

As opposed to previous zero index metamaterials, this is on chip which would allow for better integration with other photonic applications.

From the nature journal:

 

For integrated photonic applications, zero-index metamaterials require light to be confined on-chip and thus need to be realized in an in-plane geometry (that is, with the light propagating parallel to the substrate). This geometry would permit these metamaterials to be integrated with other optical elements, including waveguides, resonators and interferometers. To date, zero-index metamaterials have been demonstrated only in an out-of-plane geometry, with functional layers of the metamaterials stacked on a substrate and where light propagates normal to the sample surface12, 16, 18. This geometry is not only impractical for integrated-photonics applications, but is also limited to short interaction lengths and cannot be fabricated in arbitrary shapes.

 

The Harvard article describes the metamaterial as:

The metamaterial consists of silicon pillar arrays embedded in a polymer matrix and clad in gold film. It can couple to silicon waveguides to interface with standard integrated photonic components and chips.

 

 

Disclaimer: I do not have a formal degree in Physics and anything that has not been directly quoted could be slightly wrong due to the way that I have tried to simplify things

[MegaDave91]

[Dabombinable]

TL:DR  They figured out how to smooth light.

[Imabigmac]

TL:DR  They figured out how to smooth light.

 

I didn't even know it was rough 

[Spongy141]

For people who do not understand, basically its just good news for quantum computing (And other applications that somewhat apply to computers).

[Jerakl]

After the part about indexes of refraction (which I learned last year in physics), it's all nonsense.

 

TL;DR please

[ionbasa]

For those of you who don't know this:

 

 

Light bends, they figured out how to make an material so that light doesn't bend. 

 

Why is this helpful? And how does this help with quantum computing, etc? Well here's a really simplified explanation:

It allows the photons to not lose any energy while traveling through the material, which also means that we can send photons that are 'in phase' with each other on a small scale, similar to what an laser does (all the light is more or less in phase). The best part is that they figured out how to keep the light wave/photon in 1 plane (let's say 'z'), which means we can use tools such as waveguides (channels that direct the light) and not lose any energy guiding the light through a path. This is useful for when we decide to use light interconnects instead of electrons on CPUs to move data around.

 

There's also an use for this in quantum entanglement. Normally waves have an peak and a trough, with this, we can force an photon/light wave to constantly be at either a peak or trough. (think straight line vs sinusoidal wave (as a function of time). With that also means that the phase (or clock) of the wave approaches infinity. Where phase means a small portion of the cycle has moved from the starting position. This doesn't mean that it's traveling faster than the speed of light though! It's merely a property that we measure/define waves by. 

 

Disclaimer: This is coming from an mechanical engineer and my interpretation of the article. Someone who deals with modern/quantum physics on this forum could probably do a better job at explaining it than I did (and could probably go into more detail).

[kacper]

Wait, 0? Like literally 0?