The team is working with semiconductor optical fibres, which they claim hold significant advantages over silica-based fibre optics – the current technology used for transmitting nearly all digital data. Silica – glass – fibres can only transmit electronic data converted to light data. This requires external electronic devices that are expensive and consume large amounts of electricity.
Semiconductor fibres, however, can transmit both light and electronic data and could potentially complete the conversion from electrical to optical data on the fly, improving delivery speed.
"Glass technology has taken us this far," said Professor Venkatraman Gopalan. "My group thought it could do more by using numerous electronically and optically active materials other than plain glass. That's when we began trying to embed semiconductors into glass fibre."
The researchers’ method is said to improve the polycrystalline core of silicon fibres by melting a high purity amorphous silicon core deposited inside a 1.7µm inner-diameter glass capillary using a scanning laser.
"High purity is fundamentally important for high performance when dealing with materials designated for optical or electrical use," said doctorate candidate Xiaoyu Ji.
The team claims this method transforms the core from a polycrystal to a single crystal with fewer imperfections that transmits light much more efficiently.
"We started from a deposited amorphous silicon and germanium core and used a laser to crystallise them, so that the whole semiconductor fibre core was one single crystal with no boundaries," said Prof Gopalan.
"This improved light and electronic transfer. Now we can make some real devices, not just for communications, but also for endoscopy, imaging, fibre lasers and many more."
According to the group, the method lays out the methodology to embed a host of materials into fibre optics and to reduce voids and imperfections to increase light-transfer efficiency.
