Patent ID: 7454100

Claim:
A wavelength selective optical switch comprising: a first birefringent element for receiving input light having a plurality of wavelength components, said element adapted to decompose said input light into two light beams having different polarizations; a beam expanding device for expanding said two light beams having different polarizations in a predetermined plane; a first dispersive element receiving said expanded two light beams having different polarizations, and dispersing different wavelength components of said expanded light beams in said predetermined plane; at least one optical element for focusing said dispersed wavelength components of said expanded light beams of different polarizations onto a focal plane; a polarization rotation element located essentially at said focal plane, said polarization rotation element being pixelated generally along the direction of said dispersion such that separate pixels are associated with separate wavelength components of said expanded light, at least one pixel of said polarization rotation element being operative to rotate the polarization of light passing through said pixel according to a control signal applied to said pixel; at least one optical element for collecting said dispersed wavelength components of said expanded light beams after passing though said polarization rotation element, to regenerate two output expanded light beams; a second dispersive element receiving said two output expanded light beams and operative to combine them into two multi-wavelength output light beams; a beam compressing device aligned such that said two multi-wavelength output light beams are compressed in said predetermined plane; and a second birefringent element for combining only those wavelength components of said two multi-wavelength output light beams having predetermined different polarizations into one transmitted output beam.