Optical grooming switch with regenerative functionality for transparent interconnection of networks

All-optical regenerator of multi-channel signals

One of the main reasons why nonlinear-optical signal processing (regeneration, logic, etc.) has not yet become a practical alternative to electronic processing is that the all-optical elements with nonlinear input–output relationship have remained inherently single-channel devices (just like their electronic counterparts) and, hence, cannot fully utilise the parallel processing potential of optical fibres and amplifiers. The nonlinear input–output transfer function requires strong optical nonlinearity, e.g. self-phase modulation, which, for fundamental reasons, is always accompanied by cross-phase modulation and four-wave mixing. In processing multiple wavelength-division-multiplexing channels, large cross-phase modulation and four-wave mixing crosstalks among the channels destroy signal quality. Here we describe a solution to this problem: an optical signal processor employing a group-delay-managed nonlinear medium where strong self-phase modulation is achieved without such nonlinear crosstalk. We demonstrate, for the first time to our knowledge, simultaneous all-optical regeneration of up to 16 wavelength-division-multiplexing channels by one device. This multi-channel concept can be extended to other nonlinear-optical processing schemes.

Nonlinear optical processing devices are not yet fully practical as they are single channel. Here the authors demonstrate all-optical regeneration of up to 16 channels by one device, employing a group-delay-managed nonlinear medium where strong self-phase modulation is achieved without nonlinear inter-channel crosstalk.

A dual purpose, all optical multiplexer circuit in InP, for multiplexing clock and NRZ data, and for transmultiplexing WDM to TDM

We present a new, integrated all-optical multiplexer for wavelength grooming of many WDM channels into a single TDM channel. The chips were realized in a novel generic InP foundry process. For design and mask layout of the multiplexer circuits, we developed a simple equivalent circuit, representing the incorporated wavelength converter. With the chips realized, successful WDM to TDM transmultiplexing is demonstrated, as well as multiplexing of clock and NRZ data.