In the latest work, Knights, together with
Jason Ackert and colleagues at McMaster and also the University of Southampton in the UK, have built and tested a photodetector – a device that converts the pulses of light sent down a fibre-optic cable into electrical signals that serve as input to computer processors – that is designed to meet that demand by increasing the range of wavelengths that can be used to send data. Most current cables work at bands centred on 1.3 or 1.5 μm, and transmit data over about 100 different channels within each band – with each channel corresponding to a slightly different wavelength. The new device would, the researchers say, help to open up at least another 100 channels by operating at longer wavelengths, exploiting a band lying in the mid-infrared region at around 2 μm.
