At the time of writing, it is just over 10 years since a seemingly simple research project at Bell Laboratories led to a new revolution in optical frequency metrology, when in 1999, in a packed CLEO postdeadline session, the first public presentation of supercontinuum generation in photonic crystal (or microstructure) fibers was given (Ranka et al. 1999).

This work had started a year earlier as a curiosity I had had as a post-doc at Bell Laboratories on the possibilities of extreme nonlinear interactions in small-core high-numerical aperture (NA) silica fibers that were fabricated with a transverse microstructure or photonic crystal fiber cladding. In all honesty, at the time I did not consider the possibility that the fiber structure would so substantially alter the dispersive and modal properties of the fiber so far from the zero dispersion wavelength of bulk silica. The success of this work is a tribute to the ability of a commercial research organization to understand and encourage basic research with a long-range outlook. Having a management team step back and allow a post-doc to work independently, with support, free from bureaucratic or technical interference, allowed the project to proceed unhindered.

After a survey of a number of different fibers that our optical fiber research group had fabricated and initial calculations of potential nonlinear effects that would occur with femtosecond duration pulses, a simple fiber design was chosen to start experimenting with.