Abstract

Liquid crystal spatial phase modulator plays an important role in laser beam steering, wave-front shaping and correction, optical communication, optical computation and holography. One fundamental limitation lays in the response time of liquid crystal reorientation. To achieve fast response time, polymer-network liquid crystals are therefore proposed. By incorporating polymer network in a liquid crystal host, the response time can be reduced by a factor of 100. However, the polymer network introduces hysteresis, light scattering, and high voltage. The motivation for a fast-response liquid crystal phase modulator will be discussed in the first chapter. In the second chapter, we introduce our discovery that by modifying the polymer network structure with C12A, the hysteresis from the network can be eliminated, while keeping response time at the same order. In the third chapter, we introduce a new route toward fast response time. Instead of randomly generated network, we propose to utilize two-photon-polymerization method to create well-defined polymer scaffold. By introducing polymer scaffold, we demonstrated a 7-fold faster response in comparison with traditional phase modulators, while hysteresis, scattering, and high driving voltage are all eliminated. In the fourth chapter, we introduce phase modulation based on Pancharatnam-Berry (PB) phase principle. In this type of phase modulation, the defect at 2π phase reset in conventional phase modulators can be avoided. Therefore, a higher optical quality can be achieved, making them suitable for display and imaging applications. We demonstrated a fast PB lens with response time less than 1 ms, and using which we realized the first PB lens-based additive light field display to generate true (monocular) 3D content with computationally rendered images. In chapter five, we demonstrate the resolution enhancement based on pixel-shifting of fast PB gratings. By synchronizing display content with shifting pixels, we demonstrated ~2x enhanced resolution and significantly reduced screen-door artifact. In chapter six, we report our discovery of reflective polarization volume gratings (PVGs) based on self-organized liquid crystal helix. We achieved a large deflection angle ( > 50° in glass), high diffraction efficiency ( > 95%), and unique polarization selectivity (distinction ratio > 100:1). A system integrating PB optical elements is described in chapter seven. Finally, we will summarize our major accomplishments in chapter eight.

Graduation Date

2018

Semester

Fall

Advisor

Wu, Shintson

Degree

Doctor of Philosophy (Ph.D.)

College

College of Optics and Photonics

Department

Optics and Photonics

Degree Program

Optics and Photonics

Format

application/pdf

Identifier

CFE0007760

URL

http://purl.fcla.edu/fcla/etd/CFE0007760

Language

English

Release Date

6-15-2022

Length of Campus-only Access

3 years

Access Status

Doctoral Dissertation (Open Access)

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