The bright prospects of optical solitons after 50 years

The idea of temporal solitons in optical fibres as a means to compensate for the chromatic dispersion-induced temporal broadening of pulses via the intensity-dependent refractive index of silica (the Kerr effect) was introduced by Hasegawa and Tappert in a paper that was submitted on 12 April 1973. In this Perspective we present a brief historical overview of how this prediction developed in light of other technological developments made through the decades, followed by an extensive forward-looking discussion on the most exciting opportunities in soliton research. Since the inception of the idea of temporal solitons in optical fibres, published in 1973, the concept of optical solitons has revolutionized the fundamental science of optics and photonics technologies. This Perspective gives an outlook on the future of solitons in ultrafast lasers, frequency combs, biomedical applications, telecommunications and signal processing, as well as the emerging new science of solitons.