  Information encryption and security is a prerequisite for information
technology which can be realized by optical metasurface owing to its arbitrary
manipulation over the wavelength, polarization, phase and amplitude of light.
So far information encoding can be implemented by the metasurface in one
dimensional (1D) mode (either wavelength or polarization) only with several
combinations of independent channels. Here we successfully apply dielectric
metasurfaces in a 2D mode (both wavelength and polarization) with far more
combinations of independent channels to encrypt information, which therefore
enhances the encryption security dramatically. Six independent channels by two
circular polarization states (RCP and LCP) and three visible wavelengths (633
nm, 532 nm and 473 nm) in 2D mode can produce 63 combinations available to
information encoding, in sharp contrast with 7 combinations by 3 independent
channels in 1D mode. This 2D mode encoding strategy paves a novel pathway for
escalating the security level of information in multichannel information
encryption, anti-counterfeiting, optical data storage, and information
processing.
