The metasurfaces disrupting the display market

As display technology matures, are the days of LCD numbered? Professor Mohsen Rahmani explains how a new breakthrough could disrupt the market.

The field of display technology is a lucrative but fiercely competitive one. Today, that market is being disrupted by a new proof-of-concept development that could light the way for ‘next-generation’ displays beyond the current capabilities of today's flat panels.

With the maturation of flat panel technology, limitations have been discovered that make long-term improvements of this technology difficult. If this is the end of the road for traditional flat panels, what could be coming next? Look no further than a new proof-of-concept technology that could pave the way for solid-state display technology with a high-resolution and fast refresh rate.

Enter metasurface pixels: a breakthrough in optical technology that could enable screens and electronic devices to become thinner, offer higher resolutions and lower carbon footprints through greater energy efficiency.

This development was pioneered by an experienced, international team of researchers from Nottingham Trent University, the Australian National University and the University of New South Wales Canberra, headed by visionary and photonics expert: Professor Mohsen Rahmani.

"By changing just one layer, this minimal improvement could significantly improve a display’s performance." - Mohsen Ramani, Nottingham Trent University 

Rahmani has an extensive resume in the world of advanced optics and innovation, serving as professor in nano-technology, optics and photonics at Nottingham Trent University as well as serving as the chair of the IEEE Nanotechnology Council in the UK and Ireland, in addition to other roles.

“Today, we are in a transition period”, says Rahmani, “The lenses in glasses that shape the wayfront of light are the exact same lens technology that Galileo used in his telescopes 400 years.

“Now, there is a unique technique that is replacing these old lenses. By having an area of nanoparticles that are designed in terms of material dimension and separation, we can technically recreate the function of these optics such as mirrors, lenses, and prisms. These areas of nanoparticles are roughly a hundred times thinner than human hair, but they can do the same job. These are metasurfaces.”

Today’s LCD displays use liquid crystal cells that are responsible for switching the transmitted light on and off, lit by a backlight with polarising filters in the front. and behind the pixels. Liquid crystals determine the dimension of pixels, the resolution, and play a key role in managing the device’s power consumption.

The metasurfaces are 100-times thinner than liquid crystal cells, offering a resolution ten-times greater than LCD capabilities with a 50% reduction in energy consumption and the ability to switch light effectively at high frequencies.

Rahmani explains: “The metasurfaces can be tuned electrically by applying voltage. By applying voltage, we can control the light passing through. This is what liquid crystal pixels does already, however because they use liquid, pixels cannot be too thin and too close to each other [without negative impacts].

“Displays are one of the applications of what we can do with this technology”, adds Rahmani, “Liquid crystals are one of the layers inside LCD and backlit LED displays. Our nanoparticles can be used instead of liquid crystals without changing the other layers, in fact you can even remove some layers such as polarisers. It is an improvement over current liquid crystal displays.”

The metasurfaces can also be used for deflecting light, as Rahmani explains: “Many consider these metasurfaces to be the building block of the modern optical elements in the 21st century. All these big optical elements and mirrors will soon be replaced by metasurfaces. The advantage of this technology is that it has the potential to offer several functions at the same time from the same metasurface, simply by tuning it. You can have one device with several functions, for example, by adjusting the focal lens on demand.”

LCD displays feature two polarised layers of light to allow light through, using liquid crystals to change the direction of the polarisation or block the light when a voltage is applied, however the metasurfaces can work with unpolarised light to improve performance and efficiency.

“Our technology also has an advantage over backlit LED as it does not depend on the polarisation of light”, says Rahmani, “polarising the light is difficult in current displays because optical switches and liquid crystal displays require polarisers. The beauty of our metasurfaces is that they are polariser independent, working with unpolarised light. This is a big technical advantage.”

Today, Rahmani’s team is in discussions with manufacturers to integrate the breakthrough technology by changing just one layer in their displays.

Rahmani clarifies: “[Our metasurfaces] are attractive to manufacturers because they want to integrate our technology by changing just one layer in their displays, they don’t want to build a new production line from scratch. Companies want a technology that offers a long lifespan, is cheap and can provide higher resolution; our technique can offer this. By changing just one layer, this minimal improvement could significantly improve a display’s performance, decrease power consumption, decrease the thickness of a display and increase resolution.”

While this optical marvel has been six years in the making, Rahmani’s team aims to license the metasurface technology to manufacturers, exploiting the existing infrastructure of manufacturers to rapidly develop next generation displays.

“We are now in conversation with big display manufacturers”, says Rahmani, “explaining the technology and helping them to realise that they only need minimal changes to their production lines to make significant improvements to the performances of the display.

“We hope that, when the industry takes this technology on board for use, they can use the resources and facilities that they have to speed up the development of displays. When we academics do something cool, we either have the option of making a spin-off company or licensing it to bigger companies. We really don’t have time to create a spin-off, so we will let the manufacturers take it from here.”

For Rahmani and the team, licensing the technology is not the end of the road. With years of experience in optics and photonics, more research and breakthroughs will be forthcoming for both the display market and beyond.

Rahmani closes: “It is our job to keep improving technology, looking at other applications as well. At the moment, we are consulting on applications for the display world. These metasurfaces are optical switches and they can be used in a lot of different devices. Displays are just one application. There are other applications for optical switches that we are working on at the moment.”

Article Categories

Most Viewed