In this letter, we propose a voltage-controlled optical filter based on electrowetting. The device is made of a transparent cubic cell filled with two immiscible liquids having three indium tin oxide electrodes fabricated on the bottom substrate of the cell. A conductive droplet carrying a color filter is placed on the ITO electrode and the surrounding liquid is density-matched silicone oil. Under zero bias, the droplet is placed in the middle of the substrate and white light passes through the filter and we can see red light on the screen. When a voltage is applied to the device, the filter moves with the liquid based on electrowetting effect, we can see the white light on the screen. Due to the movement of the liquid, our device functions as an optical switcher. The switch time of the device is ~70 ms. The proposed device has a wide application in optical communication, electronic display, and optical switch.
A transflective polymer-stabilized blue-phase liquid crystal display(BP-LCD) with a non-uniform etching substrate is proposed.In-plane switching(IPS) electrodes on the bottom substrate are put on the different gaps,and the bottom substrate between the electrodes is etched into different depths in transmissive(T) and reflective(R) regions.This structure can balance the optical phase retardation in the two regions and is helpful to achieve well-matched voltag-dependent transmittance and reflectance curves.This transflective display has high optical efficiency,a wide viewing angle,and low operating voltage(approximately 6 V).
In this Letter, we propose a color holographic zoom system based on a liquid lens. We use the spatial multiplexing method to realize color reconstruction. By controlling the focal lengths of the liquid lens and the encoded digital lens on the spatial light modulator panel, we can change the magnification of the reconstructed image very quickly, without mechanical parts and keeping the output plane stationary.
The number of layers and the resolution of liquid crystal displays(LCDs) limit the reconstruction fidelity of near?eye light field displays based on multilayer LCDs. Because the eye^ resolution capability is different for central vision and peripheral vision, the fidelity can be improved by setting different weights for different areas. First we employ the eye^ modulation transfer function(MTF) to acquire the limiting resolution angle. Then, due to the inverse relationship between the limiting angle and the weight values, the weighted function related to retinal eccentricity is calculated. In combination with the linear least-squares algorithm, the peak signal-to-noise ratio(PSNR) of the reconstructed scene is raised. The simulation results indicate that the weighted optimization algorithm can improve the image fidelity and reconstruction accuracy.
