The East Anglia division of the IOP runs a photo competition each year, the photos not only being aesthetically pleasing but also showing a physical principle in action. This year we have had quite a lot of success in the laboratory physics category, with Jan Mertens winning 1st place and Matthew Millyard coming 3rd.
Matt's third place photo shows his self assembled gold nanoparticle mats. Due to the angle at which the flash was taken the photo shows light transmitted, reflected and scattered from the mats, resulting in distinct colour changes.
Jan's winning photo, titled "Light waves made visible by Christmas trees", is a sample that was made by interference lithography. The interference pattern of two incoming laser beams cures certain areas of a photoresist, the excess can then be washed away leaving this pattern behind. The Christmas tree like structure arise from a standing wave produced by back reflection of the laser light from the substrate, and so directly shows the wavelength of the incoming light.
Both photos, along with the other winning entries will be on show at Physics Fest on the 8th of December at the City academy in Norwich, where the overall winner will be announced.
Below are the two images and the captions submitted with them. These captions are supposed to be aimed at a secondary school audience and are also taken into account for the competition.
"All that is gold does not glitter" by Matthew Millyard
Since Roman times, tiny particles of gold have given stained glass its vivid colour. Different hues of light pass through and bounce off these particles, meaning their colour depends on how you look at them. Here, an array of gold nanoparticles has been photographed using an angled flash, capturing both the blue light transmitted through the sample and the reddish orange light reflected back from the particles.
"Light waves made visible by Christmas trees" by Jan Mertens
Light shapes our day – without light, we don`t see anything. Light is a wave, but in contrast to a water wave, we cannot see a wave of light. Here, we see a Christmas tree structure made with light. The trees have periodic terraces which resemble the light wave close to the flat surface allowing us to see the shape of the wave that is normally invisible to us.