Polarization insensitive tunable optical filters

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 each of the two identical filter elements of said filter structure comprises a first close loop resonator centered to the specific channel.

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;
• (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;
• and
• (c) an additional filter structure centered to an additional channel of the input light different from said specific channel, said additional filter structure being accommodated at output of the first filter structure and operating to receive and process light from two second light paths each containing all other channels of the input light except for said specific channel, to select therefrom light of said additional channel.