In recent years, there have been significant developments in lightwave technologies enabling wide exploitation of optical phase, as exemplified in particular by the dawn of Coherent Optical Communications - the key enabler for the growth in the capacity of the Internet. This is due to many key breakthroughs in laser technology (low-noise low-cost and compact lasers), new revolutionary concepts that have recently been introduced (e.g., the Optical Frequency Comb, the significance of which was demonstrated by the award of a Nobel Prize in 2005), and significant advances in electronics that, thanks to the increased speeds now possible, can accommodate the processing of very complicated coherent (amplitude + phase) signals.
Another exciting field is Hollow Core Optical fibres, which guides ligth in a central hole surrounded by a microstructure that prevents light escaping from the core. Although known for over 20 years, only very recently their fabrication enabled them to use their full potential.
