Soliton collision interaction force dependence on wavelength separation in fibre amplifier based systems

Collisions of optical solitons of different carrier wavelengths are studied in an optical system with erbium-doped fibre amplifiers and non-dispersion shifted fibres. When a collision is centred in an amplifier, significant soliton interaction resulting in spectral and temporal shifts are observed. The shift is found to be substantially reduced by increasing the wavelength separation. The shift is approximately twice as large for a collision taking place in a transmitter booster amplifier when compared with a collision in an in-line amplifier.