Abstract:
Optical pulse compression using similariton propagation in an optical fibre
with decreasing dispersion has been demonstrated for the first time. This
compression scheme is a practical application of the sech-similariton solution to the generalized nonlinear Schrodinger equation (NLSE) with distributed coefficients recently found using the self-similarity technique. The
sech-similariton solution exhibits a characteristic positive linear frequency
chirp, which increases in slope as the pulse compresses. The solution does
not develop any side pedestals or deformation in pulse shape as it propagates,
making it a promising candidate for a new compression technique. Unlike
the adiabatic compression technique, rapid compression can be achieved in a
fibre with a specifically designed decreasing group velocity dispersion profile
since the sech-similariton is an exact solution to the NLSE. A cost-effective
and efficient method of realising decreasing dispersion in a fibre has been developed using a comb-like dispersion profiling technique and its feasibility has
been experimentally demonstrated. An optimised experimental similariton
compressor system has been built using two industry standard fibres which
compressed an 11 ps linearly chirped sech input pulse to 400 fs, yielding a
compression factor of greater than 25.