Multi-functional two-dimensional holographic grating based on silver pattern coated by azopolymer

•Periodically distributed refractive index and photoinduced birefringence.•Polarization modulation is realized with stable diffraction efficiency.•Different grating structures can be recorded in the same double-layer film.•The 2D diffraction device is angle-sensitive. A two-dimensional diffraction device with the properties of polarization modulation, angular sensitivity, polarization-independent diffraction efficiency and repeatable recording has been designed and fabricated in an azopolymer-silver double-layer film by means of two-step holographic exposure. A silver pattern is formed in the light field with the sinusoidally distributed intensity, and then a polarization holographic grating is recorded in the azobenzene liquid-crystalline layer through the interference of two orthogonally linearly polarized lasers. We report here that the polarization states of the diffraction beams from the recorded two-dimensional grating are orthogonally modulated; the diffraction efficiency is related to the incident angle of the probe light and the rotation angle between the two-step recording, while independent on the incident polarization state. Furthermore, the experimental results are analyzed through the scalar diffraction theory and Jones matrices.