Novel architectural schemes for wavelength conversions in optical cross connect systems

This paper proposes simple, cost-effective schemes for wavelength conversions in optical cross-connect (OXC) systems using wavelength-fixed light sources and an optical space switch, and provides improved performance in stability and conversion range of wavelengths and channel spacing. In addition, the schemes avoid the need for the wavelength locking control that is generally needed after changing the probe beam wavelength from one wavelength to another. The technical feasibility of the proposed pre-fix scheme is investigated in terms of probe beam power through experiment of wavelength conversions based on the cross-gain modulation. The results show that the proposed wavelength conversion scheme in OXC allows a ±4 dB deviation in the probe beam power to afford a 2 dB power penalty deviation from the minimum power penalty. As long as the insertion loss deviation of an optical space switches are within ±4 dB, the proposed pre-fix scheme can be used for wavelength conversions in OXC systems for a 2 dB power penalty deviation, whereas the proposed post-fix scheme does not require an optical space switch.