This new configuration presents a huge variety of components, including controllers of polarization states different optical elements that can be inserted into blocks, optical filters based on optical fiber bragg gratings and amplifiers of rare-earth-doped fiber.

The configuration presents a great flexibility to convert wavelength along an array of them. Other optical devices can be added to this one in order to improve its functioning characteristics.

Though the invention concerns a wavelength shifter that uses degenerate fwm (four wave mixing) to perform the conversion, we also present configurations to convert wavelengths resorting to non-degenerate fwm.