A new approach to imaging which is based on random light fields in optical fibres is presented this week in Nature Communications. The scheme may allow for inexpensive imaging systems that can see in hard to reach places.
Fibres that can support multiple propagating modes of light normally scatter light and produce random, unpredictable patterns at their output. Ordinarily this is a problem for imaging, as the image is distorted as it travels, and is lost on transmission. However, if the light coming out of the fibre can be characterised correctly, the input light can be adjusted to allow for a more thorough control over the propagating beam. Tomas Cizmar and Kishan Dholakia exploit this effect to reconstruct images of fluorescent particles from the randomised information that propagates through a multimode fibre. By careful modulation of the input imaging light field, they are also able to select the depth of focus of the system, circumventing the need for focussing optics and allowing for a dynamic, real-time adjustment of the imaging system.
Their work may prove useful to enable various microscopy techniques in new environments that were previously difficult to access.