It might seem an unlikely addition to the world of fashion design, but the creators of this new fabric (right) claim that it is wearable. Mehmet Bayindir and colleagues have melted together strands of optical, metallic and insulating materials to form fibres that are then woven into what they call a “spectrometric fabric” (see page 826 of this issue). Each fibre has separate channels for transmitting light and electrical currents, and these affect each other in subtle ways to create an intricate web of optical and electrical patterns.

The fabric would make curious clothing indeed, but it serves to demonstrate the level of sophistication reached in the design of optical fibres. We are all familiar with their use in high-speed telecommunication networks, but the past decade has seen the development of a new range of optical fibres with periodic structures along their length that are on the scale of the wavelength of the light transmitted. This microstructure dramatically affects the way the light is guided through the fibres. By choosing the right pattern, fibres can be made to transmit a certain range of wavelengths, or optical pulses with specific shapes. Such tailored properties could be used, for example, in beam delivery for medical or industrial laser applications, or even in the all-optical processing of data.

Bayindir et al. go a step further and consider what fibre-based applications could benefit from both electronic and optical functionality. The main challenge is to find the right combination of metallic, insulating and semiconductor materials that can be drawn together into metres of fibres with continuous structures along their entire lengths. Using a low-melting-point material such as tin for the metal parts is crucial, the authors report.

They have come up with an application that makes the most of all the favourable features of these new fibres: a two-dimensional photodetector based on an interwoven grid. The fibres generate electrical currents when they sense light anywhere along their length, and the grid geometry provides an effective means of determining the exact location of an illuminating spot.