Pixellated Optics, a class of optical devices which preserve phase front continuity only over small sub areas of the device, allow for a range of uses that would not otherwise be possible. One potential use is as Low Vision Aids (LVAs), where they are hoped to combine the function and performance of existing devices with the size and comfort of conventional eyewear. For these devices a Generalised Confocal Lenslet Array (GCLA) is designed to magnify object space, creating the effect of traditional refracting telescope within a thin, planar device. By creating a device that is appreciably thinner than existing LVA telescopes it is hoped that the comfort for the wearer will be increased. We have developed a series of prototype GLCA-based devices to examine their real-world performance, focussing on the resolution, magnification and clarity of image attainable through the devices. It is hoped that these will form the basis for a future LVA devices. This development has required novel manufacturing techniques and a phased development approach centred on maximising performance. Presented here will be an overview of the development so far, alongside the performance of the latest devices.
We recently showed how to construct omni-directional ray-optical transformation-optics devices out of ideal thin lenses. These devices can be seen as theoretical generalisations of the paraxial, four-lens, “Rochester cloak”. Here we investigate the practical realisability of such devices. We use ray-tracing simulations to compare combinations of skew lenses of different types, including ideal lenses and phase holograms of lenses.
Pixellated optical components, for example generalised confocal lenslet arrays (GCLAs), enable the design of optical devices which cannot be realised without introducing pixellation or a similar compromise. A key concern is the degradation of imaging quality due to the combined effects of diffraction, worst for smaller pixels, and the visibility of the pixels. Here we examine the effects of these two factors on image quality through use of our custom raytracer, Dr TIM. We also outline future work in developing these ideas more rigorously and applying the conclusions to more complicated devices.
In a photo taken with a camera moving at relativistic speed, the world appears distorted. That much has long been clear, but the details of the distortion were slow to emerge correctly. We recently added relativistic raytracing capability to our custom raytracer, Dr TIM, resulting in unique combinations of capabilities. Here we discuss a few observations. In particular, photos can be sharp only if the shutter is placed correctly. A hypothetical window that changes light-ray direction like a change of inertial frame, when combined with suitable shutter placement, can correct for all relativistic-aberration effects.
We study, theoretically, omni-directional Euclidean transformation-optics (TO) devices comprising planar, light-ray-direction changing, imaging, interfaces. We initially studied such devices in the case when the interfaces are homogeneous, showing that very general transformations between physical and electromagnetic space are possible. We are now studying the case of inhomogeneous interfaces. This case is more complex to analyse, but the inhomogeneous interfaces include ideal thin lenses, which gives rise to the hope that it might be possible to construct practical omni-directional TO devices from lenses alone. Here we report on our progress in this direction.