Metasurface-enabled polarization-independent LCoS spatial light modulator for 4K resolution and beyond

With the distinct advantages of high resolution,small pixel size,and multi-level pure phase modulation,liquid crystal on silicon(LCoS)devices afford precise and reconfigurable spatial light modulation that enables versatile applications ranging from micro-displays to optical communications.However,LCoS devices suffer from a long-standing problem of polarization-dependent response in that they only perform phase modulation on one linear polarization of light,and polarization-independent phase modulation-essential for most applications-have had to use complicated polarization-diversity optics.We propose and demonstrate,for the first time,an LCos device that directly achieves high-performance polarization-independent phase modulation at telecommunication wavelengths with 4K resolution and beyond by embedding a polarization-rotating metasurface between the LCoS backplane and the liquid crystal phase-modulating layer.We verify the device with a number of typical polarization-independent application functions including beam steering,holographical display,and in a key optical switching element-wavelength selective switch(WsS),demonstrating the significant benefits in terms of both configuration simplification and performance improvement.