Multi-Spatial-Harmonic Intensity Tailoring Based on Nonlinearly-Phased Reprogrammable Grating

In this paper, we report a nonlinearly-phased reprogrammable grating to reconstruct electromagnetic wavefronts dynamically. Each unit cell of such the grating integrates a varactor diode to enable large phase coverage of more than 305° with low reflection loss less than −2dB. By adjusting nonlinear phase distributions at the grating interface properly, reflection angles and reflection intensities of interested spatial harmonics can be modulated as desired, thereby reconstructing various electromagnetic wavefronts. As a proof of concept, two-spatial-harmonic intensity tailoring is presented and verified. Good agreement between simulation and experimental results shows that the proposed grating enables intensity tailoring of multiple spatial harmonics in an arbitrary and precise manner.