相位延遲板常被在一些光學系統中，而液晶相位延遲板因具有價錢低、重量輕、低電源損耗及無須機械移動等優點，因此引起很大的關注。但大部分的液晶相位延遲板操作時，普遍需要高達35V以上的操作電壓持續外加在元件上。
本論文主題是利用摻雜十二氫氧基硬脂酸 (12-Hydroxystearic Acid, HSA)的液晶樣本，製作出具有多重穩態特性之高相位延遲板。其原理是利用HSA其自組織性質，使HSA摻雜液晶樣本在室溫時呈現膠狀，達到液晶相位延遲板可穩固在不同相位，亦即多重穩態，因此可達到省電的功用。操作方式是利用控溫器讓液晶盒溫度從室溫上升到70℃，接著加適當電壓調控液晶盒的相位，在施加電壓的狀態從70℃緩慢降溫到室溫，再移除電壓，藉由外加不同的電壓，即得到不同相位的液晶波板。在外加電壓為零時，將可得到4π的相位延遲板。外加電壓為3.5 V及7.1 V時，分別得到1/2與1/4液晶波板。此液晶相位延遲板具有高相位延遲以及低操作電壓的優點，並且具有多重穩態的特性，因此具有高應用潛力。

Phase retarders have been commonly employed in optical systems. Liquid crystal-based phase retarders attract much attention, because they offer several advantages, such as low cost, light weight, low power consumption and no mechanical moving part. But, majority of liquid crystal-based phase modulators still need an operating voltage ~35 V.
This thesis demonstrates a multi-stable, large phase-retardation plate using 12-Hydroxystearic Acid (HSA) doped liquid crystals. The mechanism is that hydrogen-bond forces between HSA molecules make the HSA doped LC material to form a gel compound in room temperature. Therefore, various alignment directions of LCs can be stabilized to achieve the so-called multi-stable characteristics, which can be used to save power consumption. Experimental processes are: firstly, to control the temperature of sample to ~70 ℃, secondly, to apply a voltage to the sample, and then cool the sample from 70 ℃ to room temperature, finally, to turn off the applied voltage. After a specific process, a LC wave plate with designed phase retardations can be obtained by applying various voltage in the process. Experimentally, a maximum phase retardation 4π can be obtained presently. When voltages of 3.5 V and 7.1 V are applied in the process, a 1/2 and 1/4 wave plates are achieved, respectively. Therefore, the phase-retardation plate using HSA doped LCs possesses a large phase retardation, low operating voltage and multi-stable characteristics, and is potential for practicality application.

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