Experimental Observation Of Adiabatic Compression And Expansion Of Soliton Pulses Over Long Fiber paths.

In a recirculating 42km fiber loop with round-trip loss compensated by Raman gain, we have used excess gain to study the influence of adiabatic energy changes on the propagation of soliton pulses over fiber paths ranging from hundreds to thousands of kilometers. Both measured pulse shapes and the corresponding optical spectra vary in agreement with simple scaling laws, and maintain the expected time-bandwidth product.