| dc.description.abstract | The research topic, divided into three sections, of this thesis is about liquid crystal (LC) optoelectronic devices which provide the property of privacy protection. In the first section, we propose an asymmetrical transmission smart window based on dichroic dyes-doped LC. A LED light bulb and narrow-band filters for different wavelengths are combined to be the indoor light source. The standardized light, D65, is a broadband light source used as the outdoor light source. Asymmetrical property of the smart window can be achieved through the difference of transmission spectra between narrow-band indoor light source and broadband outdoor light source when the both light sources penetrate through the smart window from opposite sides. Since the ideal asymmetrical property could not be easily obtained experimentally, numerical simulations are conducted using the program to design different indoor light sources and dyes with suitable absorption spectra to optimize the smart window system ideally. For simulation, the indoor reference light sources with color temperatures of 6500K and 3000K are selected, and the outdoor reference light source is set to be the standardized light, D65. The second and third sections in this thesis report two types of displays with privacy protection which are designed according to the properties of linearly polarized light and circularly polarized light. Briefly, the privacy information is displayed on a reflective liquid crystal spatial light modulator (RLC-SLM), playing the role of a half-waveplate to modulate the polarization state of the reflective light. Therefore, the polarization states of the reflective lights with and without the privacy information are mutually orthogonal, which is the key point of the display reported in the second section. In addition, the reflective SLM with the displayed information has also been observed under a polarized optical microscopy (POM). According to the observation, it can be concluded that the visible privacy information, which can be viewed on the screen without any analyzer in the experiment, is caused by the differences of LC alignment between the adjacent pixels experimentally. The third section is subdivided into two parts for detailed discussion, including experiments and pixel-designs. In the experiment part, the linearly polarized light emitted from the display is modulated to circularly polarized light by using a broadband quarter-waveplate film. To accomplish the property of privacy protection, the combination of the broadband quarter-wave plate film and the polarizer to be a circular polarizer is needed. For the pixel design, the two pixels in odd and even rows are combined into one composite pixel beneath different broadband quarter-waveplate films with two orthogonal fast axes, so that the pixels in odd and even rows emit circularly polarized light with opposite handednesses. Finally, with the adjustment of the output light intensities of the pixels in odd and even rows, the privacy information can be viewed on the privacy-protected display with a circular polarizer. | en_US |