以二階相位光柵的一階繞射光強量測Pluto相位調變器之研究

The study of Pluto using the first-order diffraction of binary phase grating

呂昱緯(Yu-Wei Lu)

指導教授 ： 徐巍峰

國立臺北科技大學/電資學院/光電工程系研究所/碩士(2014年)

https://doi.org/10.6841/NTUT.2014.00649

摘要

矽基型液晶空間光調變器(Liquid-crystal-on-silicon spatial light modulator, LCOS-SLM)是種能將入射光波進行振幅及相位調變的元件，原理為利用液晶隨外加電壓而轉向的特性，使光波造成相位延遲而可達到相位的調變。液晶空間光調變器相較於傳統繞射光學元件方便及快速，廣泛用於顯示應用、光斑消除。
本研究檢測之液晶空間光調變器為Holoeye公司製造的Pluto，在使用Pluto前，我們需量測此元件對光的振幅及相位調變特性。本研究會延續學長的方法，並做了些改良，以避免掉量測上的誤差。在量測振幅調變上，我們研究光由不同角度入射對Pluto的反射率。實驗架構為在Pluto上播放灰階，並使用兩個光功率計，作為監控光及反射光用，所量得的值可以推算出反射率。在量測相位延遲量方面，我們在Pluto上播放二階光柵，其產生的一階繞射點的光強值，可計算出實際相位延遲量。最後將實驗結果分析，統整出Pluto的特性。

關鍵字

矽基型液晶空間光調變器 ； 繞射光學元件 ； 相位延遲

並列摘要

The liquid-crystal-on-silicon spatial light modulator (LCOS-SLM) is an element which modulates the amplitude and the phase of plane wave. LCOS-SLM provides a relative phase delay to the incident light depending on the applied voltage which is controlled by a computer. In contrast to the traditional diffractive optical elements, LCOS-SLM can be more conveniently and fast used in many applications such as image projection displays and speckle reductions.
The liquid-crystal-on-silicon spatial light modulator (LCOS-SLM), Pluto (Holoeye Photonics, AG), is used to implement phase-only diffractive optical elements in our laboratory. Prior to using Pluto as the diffraction optical elements, we developed a fast and reliable method to standardize the intensity and phase modulations of Pluto. According to the study of seniors, we made some improvement to reduce the errors of measurement. To measure the intensity reflectance, we studied the reflectance curve of the incidental wave from different angles to Pluto. We displayed grayscale patterns in Pluto as our structure of study, and used two power meters to obtain the power of intensity of reference beam and the reflective beam. To measure the phase delay, we measured the first-order intensity by using the binary complex valued grating patterns, with a fixed gray level and a varying gray level. Finally, the characteristics of Pluto were summarized by analyzing of results of our experimental results.

並列關鍵字

LCOS-SLM ； Fraunhoffer diffraction, ； DOES

參考文獻

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