Pulses of Four Optical Cycles from an Optimized Optical Fibre/Grating Pair/Soliton Pulse Compressor at 1·32 μm

Abstract
In this Letter, we report on the generation of pulses as short as 18 fs by means of an optimized two-stage optical fibre-grating pair and high-order soliton-effect pulse compressor. These are the shortest pulses yet reported in the near-infrared spectral region and correspond to four optical cycles at 1·32 μm.