The Tartan Geometry of Light
As a research group based in Scotland we are naturally proud and excited every time light reveals its tartan nature to us.
Below are a few of the generalised optical tartans we discovered.
Video-feedback tartan
This tartan was observed at the same time as the other video-feedback patterns shown in Leach et al., Fractals in pixellated video feedback, Contemp. Phys. 44, 137 (2003), https://doi.org/10.1080/0010751021000029598.
Tartan with a dislocation
Colour representation of a phase hologram (shown in Fig. 4(d) in Gibson et al., Free-space information transfer using light beams carrying orbital angular momentum, Opt. Express 12, 5448 (2004), https://doi.org/10.1364/OPEX.12.005448). It clearly has a discontinuity at its centre, but as far as generalised tartans go this one is very generalised.
Diffraction tartan
Far-field diffraction pattern behind a 90° ray-rotating sheet (Hamilton et al., Local light-ray rotation, J. Opt. A: Pure Appl. Opt. 11, 085705 (2009), http://dx.doi.org/10.1088/1464-4258/11/8/085705). It looks like part of a tartan, complete with stitches. #weavedbydiffraction
The official tartan of the University of Glasgow
... can be found at https://www.tartanregister.gov.uk/tartanDetails?ref=1360. We also didn't know that the University of Glasgow had one.