Editorial Feature

A New Kind of Pixel- The Plasmonic Metapixel

High resolution microdisplays that use liquid-crystal-on-silicon (LCoS) technology are commonplace these days. They are found across various optical modulation applications including projectors, telecommunication switches and head-mounted displays. However, with the rise in photonics, a pixel’s surface area is underutilized and the potential for the phenomena associated with plasmonic nanostructures is far reaching.

A team of Researchers from the University of Cambridge, UK, have demonstrated a plasmonic metapixel, which offers a unique spectral (full RGB) and polarization control, as novel pixel elements for state-of-the-art high-resolution reflective microdisplays.

Modern day technology commonly utilizes liquid-crystal-on-silicon (LCoS) technology, using pixels that utilize reflective surfaces on top of electrical backplanes. Whilst many devices are considered state-of-the-art, each pixel in use in these technologies are confined to a single fixed color that will only modulate the amplitude of light.

A single pixel is commonly composed of linear polarizers, RGB pigment-based color filters and an electrically switchable waveplate, which is a liquid crystal layer which sits on top of a mirror-quality reflector- a square aluminum electrode, roughly 10 μm2 in size, which is connected to electronic circuitry.

However, this size is very rarely utilized to its full potential and nanophotonics has been stipulated to be the next logical step to achieving a pixel’s full potential, but have been subsequently limited in commercial applications by a low reflectance stemming from plasmonic losses and sub-optimal design schemes.

The team of Researchers have used a combination of experimental and computational approaches to develop plasmonic metapixels which incorporate in-plane 2D amplitude functions on the pixel itself, which are encoded within the nanostructures.

The Researchers designed Gaussian-profile plasmonic pixels to specifically tailor the color properties on the sub-pixel level. The design introduced non-rectangular pixels where the polarization controlled the color spatial functions and were compatible with liquid crystal waveplates. The approach was different to most, which only utilize square pixels that encode amplitude only.

To realize this, the used a combination of silver (30 nm), silicon dioxide (100 nm), aluminum (100 nm) and bulk silicon layers. All of which are compatible with current LCoS technologies and can be easily integrated.

The Researchers designed the devices using MATLAB and used remote plasma RF sputtering and electron beam lithography (EBL, Nanobeam Ltd.) methods to create the layered structure. The device was characterized using optical microscopy (Olympus BX-51 polarizing optical microscope), ultraviolet-visible spectrometry (UV-Vis, Ocean optics UV-VIS HR2000+) and scanning electron microscope (SEM, Carl-Zeiss).

The Researchers varied the grating width, designs and degree of polarization to produce plasmonic metal-insulator-metal (MIM) pixels, which utilized the aluminum reflectors as back reflectors, colloquial to that of a traditional MIM pixel. These new pixels also offer a unique spectral (full RGB) color filtering from the excitation of resonant modes and polarization control from the anisotropic nanostructures within the layered device.

The developed plasmonic metapixel was found to permit a high reflection capability whilst producing vivid, polarization switchable, wide color gamut filtering. The ultra-thin geometries within the device were found to produce an excitation of the hybridized absorption modes within the visible spectrum, and included surface plasmons and quasi-guided modes. It was found to be possible to tailor the absorption modes to target specific wavelengths, which resulted in pixels that produced a multicolour reflection on mirror-like surfaces.

The Researchers extended the concepts to incorporate 1D and 2D nanostructures, which led to dual resonant behavior and vivid color profiles. The Researcher also tailored 2D gaussian profiles across the pixels with the aid of isolated nanostructures, resulting in unique 2D functions at different wavelengths. These effects were found to be controlled by the polarization and therefore compatible with existing technologies.

The work produced has removed the need for additional input polarizers and pigment-based color filters and instead utilizes in-plane pixel color functions which are not limited by the conventional square/rectangular form commonly seen.

The choice of materials and dimensions used also lend this design to be highly compatible with a range of scalable manufacturing methods. Including extreme-UV photolithography and nanoimprint lithography, and is therefore an excellent candidate for commercial scale applications– especially as novel pixel elements in state-of-the-art high-resolution reflective microdisplay technologies.

Image Credit:

RioAbajoRio/ Shutterstock.com


“Nanostructured plasmonic metapixels”- Williams C., et al, Scientific Reports, 2017, DOI:10.1038/s41598-017-08145-0

Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of AZoM.com Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.

Liam Critchley

Written by

Liam Critchley

Liam Critchley is a writer and journalist who specializes in Chemistry and Nanotechnology, with a MChem in Chemistry and Nanotechnology and M.Sc. Research in Chemical Engineering.


Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Critchley, Liam. (2017, August 22). A New Kind of Pixel- The Plasmonic Metapixel. AZoOptics. Retrieved on April 16, 2024 from https://www.azooptics.com/Article.aspx?ArticleID=1255.

  • MLA

    Critchley, Liam. "A New Kind of Pixel- The Plasmonic Metapixel". AZoOptics. 16 April 2024. <https://www.azooptics.com/Article.aspx?ArticleID=1255>.

  • Chicago

    Critchley, Liam. "A New Kind of Pixel- The Plasmonic Metapixel". AZoOptics. https://www.azooptics.com/Article.aspx?ArticleID=1255. (accessed April 16, 2024).

  • Harvard

    Critchley, Liam. 2017. A New Kind of Pixel- The Plasmonic Metapixel. AZoOptics, viewed 16 April 2024, https://www.azooptics.com/Article.aspx?ArticleID=1255.

Tell Us What You Think

Do you have a review, update or anything you would like to add to this article?

Leave your feedback
Your comment type

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.