Patent ID: 7120333

Claim:
A filter device for filtering a multi-channel randomly polarized light signal to select therefrom at least one specific channel, the device comprising: (a) a polarizer assembly for processing the multi-channel randomly polarized light signal to split it into two multi-channel light components of a predetermined polarization identical for both of said two multi-channel light components and for processing two identically polarized light components to produce a randomly polarized light signal; and (b) a filter structure comprising two identical filter elements exhibiting substantially identical wavelength dependent response operable to process said two multi-channel light components of said predetermined polarization to select from each of said two light components a specific channel and thereby produce two first output light components of the specific channel propagating through spatially separated first light paths, wherein the two identical filter elements are tunable to said predetermined polarization condition and said selected channel by using one of the following effects: mechanical, electro optic, thermo optic, free carriers injection, and piezoelectric changes in the size or refractive index.