Patent ID: 7330658

Claim:
A device for optical add/drop multiplexing of a wavelength multiplexed optical signal comprising a plurality of wavelength channels comprising: a first MMI coupler comprising an input, an output and MI/MZI ports, and arranged for receiving the multiplexed signal at said input, for splitting the multiplexed signal into components, and for imaging these components at said MI/MZI ports; waveguides and wavelength selective means, wherein the waveguides are arranged for receiving and transporting the components imaged at the MI/MZI ports of the first MMI coupler and the wavelength selective means are arranged for transmission of the components received and transported by the waveguides, which combined constitute a first of said plurality of wavelength channels, and reflection of components received and transported by the waveguides, which combined constitute the other of said plurality of wavelength channels; and a second MMI coupler comprising two MI/MZI ports and an output and arranged for receiving the components transmitted through the wavelength selective means, which combined constitute the first of said plurality of wavelength channels, at said MI/MZI ports of said second MMI coupler, and for combining of these received components such that they are imaged at the output of said second MMI coupler; wherein the first MMI coupler is further arranged for receiving the components reflected by the wavelength selective means which combined constitute the other of said plurality of wavelength channels, at the MI/MZI ports of said first MMI coupler, and for combining these received components such that they are imaged at the output of said first MMI coupler.