Liquid crystal grating and manufacturing method thereof

Abstract

The invention discloses the structure of a liquid crystal grating. The liquid crystal grating comprises an upper substrate, a lower substrate and liquid crystals, wherein a transparent conducting thin film is arranged on the upper substrate, lower strip-shaped grounding electrode layers are sequentially etched on the lower substrate, a first dielectric layer is deposited on lower grounding electrodes, addressing electrodes which are parallel to the lower grounding electrodes in a staggered mode are formed on the dielectric layer, a second dielectric layer is deposited on the addressing electrodes again, then upper strip-shaped grounding electrodes which are overlapped with the lower grounding electrodes are formed on the second deposited dielectric layer, and the liquid crystals are clamped between the upper substrate and the lower substrate. According to the liquid crystal grating, a transverse electric field between addressing electrodes in a traditional liquid crystal grating and grounding electrodes of an upper glass substrate is effectively restrained through the shielding effect of the upper grounding electrodes and the lower grounding electrodes on the lower glass substrate on an addressing electrode power line, and therefore the edge electric field extending to a non-addressing electrode area is restrained. The structure of the liquid crystal grating can be used for the design of liquid crystal grating with the high resolution and the large deflection angle.

Description

technical field [0001] The invention relates to an optical device, in particular to a liquid crystal grating for suppressing fringe electric field. Background technique [0002] Compared with traditional mechanical devices, liquid crystal gratings have various advantages such as small size, low driving voltage, low power consumption, high resolution, and convenient change of diffraction characteristics, and can be widely used in diffractive optics, spectroscopic measurement, Beam deflection control, optical information processing, optical computing, optical communication and other fields. [0003] The basic device structure of liquid crystal phase grating is as follows: figure 1 As shown: a nematic liquid crystal 14 with dielectric anisotropy is filled between the upper glass substrate 16 and the lower glass substrate 11 to form a liquid crystal cell. A transparent address electrode 12 and a liquid crystal alignment film 13 a are formed on the lower glass substrate 11 , an...

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Problems solved by technology

This will lead to the broadening of the phase modulation curve and the reduction of the phase modulation depth, such as Figure 4 shown

Finally reflected in the reduction of diffraction efficiency, such as Figure 5 As shown, the diffraction efficiency of the positive and negative orders is less than 10%, while the diffraction efficiency of the zero order exceeds 80%, indicating that most of the incident light cannot be effectively deflected

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