Continuously Axis-Varying Polaroid for Power-Free Transmittance Tunable Glass

The ability to continuously alter the light transmittance through a window is significant for many optoelectronic devices. However, such versatility usually comes with additional unwanted power consumption. Here, we demonstrate transmittance-tunable glass that operates without electrical power. The key element to the device is an axis-varying polarizer, which combines a photoalignment technique with dichroic dye self-assembly mechanism. By linear translation of one patterned polarizer with respect to the other, different transmittance states can be achieved. Large-scale uniformity and relatively wide viewing angles (±60°) are also demonstrated. Furthermore, low-temperature treatment (i.e., T <; 80 °C) during fabrication demonstrates the device's potential to be made on the plastic substrate. The polarizer with patterned absorption axis can also be used as other optical components such as light amplitude shaping device.