Patent ID: 9575389
Date: 2017-02-21
CPC Classifications: G02F,G03F

Claim:
1. A light modulator which modulates light propagating in a propagation direction, comprising: a first electro-optic crystal substrate having a first periodic polarization reversal structure including a plurality of first and second polarization sections alternately arranged in a first period along a first arrangement direction orthogonal to the propagation direction to allow the light to propagate through the first periodic polarization reversal structure, directions of polarization developed in each first polarization section and each second polarization section in response to electric fields being opposite to each other; a second electro-optic crystal substrate having a second periodic polarization reversal structure including a plurality of third and fourth polarization sections alternately arranged in a second period along a second arrangement direction orthogonal to the propagation direction to allow outgoing light from the first electro-optic crystal substrate to propagate through the second periodic polarization reversal structure, directions of polarization developed in each third polarization section and each fourth polarization section in response to electric fields being opposite to each other; and a driver that applies a voltage upon the first electro-optic crystal substrate and the second electro-optic crystal substrate to create diffraction gratings inside the first periodic polarization reversal structure and the second periodic polarization reversal structure, thereby modulating the light, wherein the first period and the second period are different from each other.