Optical dark-soliton generators and detectors

An optical signal integrator and an optical signal differentiator are proposed as a means of generating and detecting optical dark solitons, respectively. An optical dark-soliton generation scheme, in which the optical signal integrator is incorporated, is shown to convert a 'bright-squared' soliton signal into a fundamental dark-soliton signal. We show that the optical signal differentiator and a Butterworth low-pass optical filter can convert a fundamental dark-soliton signal into a conventional return-to-zero signal and into an inverted non-return-to-ten, signal, respectively. The proposed optical dark-soliton generation scheme, optical signal differentiator and Butterworth low-pass optical filter are synthesized using integrated-optic planar lightwave circuit technology to enable stable generation and efficient detection of high-speed dark-soliton signals.