Manipulating the various properties of light wavefronts at the micro and nanoscale has been a highly fascinating topic in recent years, including the phase, angular momentum, frequency, and polarisation of light.

Array of colours on a compact

Achieving frequency domain modulation of light in the visible spectrum using artificially fabricated micro/nanostructures enables the creation of vivid and high-resolution colours. The related research, known as structural colour, holds significant importance for next generations of full-colour displays, hyperspectral colour detection and reconstruction.

Polarisation Encrypted JWNC-UOFG
Letter at micron-scale

JWNC and UoG mapped onto an etch

Artwork reproduction

Artwork reproduction at micro-level

S. Wu et al proposed and fabricated a two-dimensional nano-aperture array structure to achieve the simultaneous manipulation of polarisation and colour[1]. A periodic hole structure is patterned onto ZEP520A or CSAR using the electron beam lithography (EBL) writer at JWNC and then transferred to the sample via ICP dry etching. The authors have demonstrated the reproduction of several notable oil paintings at the microscale, as well as a case of polarisation-encrypted display. They plan to apply the proposed structure to direct integration with detectors, aiming to realise multimodal imaging[2].

Application

  • Single Layer colour-polarisation filter array
  • A low cost RGB-pol camera filter layer solution

Images of each stage of the etching process   Reproduction of Van Gogh Sunflower painting

CSAR-Ebeam fabed High Saturation Structural Colour

  • CSAR, low-cost alternative to ZEP as ebeam resists.
  • However resistance with –Cl, -F is lower than ZEP
  • SiO2 layer as hard mask and capping layer
  • Electra 92 as top layer for dissipation

Image outlining various applications

 

[1]        S. H. Wu, P. W. R. Connolly, V. Pusino, G. S. Buller, D. R. S. Cumming, Adv Sci (2025), 12, 2501941. https://doi.org/10.1002/advs.202501941.

[2]        Y. D. Shah, P. W. R. Connolly, J. P. Grant, D. Hao, C. Accarino, X. M. Ren, M. Kenney, V. Annese, K. G. Rew, Z. M. Greener, Y. Altmann, D. Faccio, G. S. Buller, D. R. S. Cumming, Optica (2020), 7, 632-639. https://doi.org/10.1364/Optica.389905.

First published: 15 December 2025

<< The JWNC Chris Wilkinson Award: Pioneering Nanofabrication