Parametric wavelength conversion and cross-connect architectures for scalableall-optical networks

Abstract

Wavelength conversion in WDM networks offers wavelength contention resolution and distributed network management. While it is desired that the wavelength interchanging cross-connect gradually increase the degree of wavelength conversion as the network evolves, existing wavelength interchanging cross-connect architectures based on conventional variable-input to fixed-output wavelength converters do not offer such scalable or modular upgrades. Parametric wavelength conversion based on difference-frequency generation offers simultaneous conversion of multiple input channels without significant crosstalk or cross-mixing terms. The converted wavelength varies with the input wavelength, and results in variable-input-variable-output wavelength conversion. Such unique characteristics of the difference-frequency-genration wavelength converters are exploited in designing a wavelength-interchanging cross-connect architecture which scales in a modular manner. This paper examines and demonstrates the case for scalable upgrades of wavelength interchanging cross-connects based on parametric wavelength converters. We experimentally demonstrate simultaneous multichannel conversion with extremely low crosstalk in parametric wavelength conversion. We discuss the capability of upgrading a wavelength selective cross-connect to a partially blocking wavelength interchanging crossconnect, and eventually to a rearrangeably non-blocking wavelength interchanging crossconnect by incrementally adding appropriate modules.