Low-aberration liquid crystal lens with positive and negative focal length

Abstract

A low-aberration hole-patterned-electrodes (HPE) liquid crystal (LC) lens with positive and negative focal lengths is demonstrated in this Letter by using four hybrid-aligned nematic LC layers filled with dual-frequency LC materials. The diopter can be controlled from the positive lens ( 0 D ∼ 1.1 D ) to the negative lens ( 0 D ∼ − 1.25 D ). The aberration is analyzed using the Zernike polynomial, and the wavefront optical path difference is improved from 2 λ for the conventional one-layer HPE LC lens to less than 0.25 λ for our proposed LC lens. The proposed LC lens does not require the use of a polarizer, increasing the optical efficiency two times compared with the conventional LC lens.

An adaptive lens with large focusing dynamic range based on PDMS gel

“…To overcome the limitation of the traditional focus tunable lenses, two mechanisms have been widely used recently: changing the refractive index or reshaping the lens curvature. The lens based on the refractive index change such as the liquid crystal lenses, has the advantages of simple and stable, but Due to the problems of liquid crystal itself, such as slow response speed, light scattering, polarization correlation, low optical efficiency (less than 50%), small viewing angle, etc., it is difficult to make a liquid crystal adaptive lens with high optical performance and a large range of focal length [8][9][10][11] . Lens curvature variation can be classified into two types: 1) liquid lenses based on electro-wetting or dielectro-wetting principle by altering the position of the two immiscible liquids of different refractive index.…”