Polarization-independent tunable optical filters using bilayer polarization gratings.
Polarization-independent tunable optical filters using bilayer polarization gratings.
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DOI：
10.1364/ao.49.003900
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发表时间：
2010-07
期刊：
影响因子：
1.9
通讯作者：
Elena Nicolescu;M. Escuti
中科院分区：
文献类型：
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作者：
Elena Nicolescu;M. Escuti
我们展示了一个偏振无关的可调谐光学滤波器的基础上形成的可切换的偏振光栅（PG）使用反应性和非反应性液晶（LC）。PG是各向异性衍射光栅，其表现出独特的特性，包括与入射偏振无关的零阶透射率，并且可以根据波长和施加的电压从大约0%变化到大约100%。不同厚度的几个PG的堆叠与元素角度滤波器相结合，产生与偏振无关的带通调谐，具有最小的损耗。我们介绍了一种新的混合PG组成的反应性和非反应性LC层，它允许非常厚的光栅创建薄的有源LC层。我们展示了一个可调谐光学滤波器的峰值透射率为84%的非偏振光，在64 nm的最小半高全宽，和140 nm的最大调谐范围。
We demonstrate a polarization-independent tunable optical filter based on switchable polarization gratings (PGs) formed using reactive and nonreactive liquid crystals (LCs). PGs are anisotropic diffraction gratings that exhibit unique properties, including a zero-order transmittance that is independent of incident polarization and that can vary from approximately 0% to approximately 100%, depending on wavelength and applied voltage. A stack of several PGs of varying thicknesses combined with an elemental angle filter yields polarization-independent bandpass tuning with minimal loss. We introduce a novel hybrid PG consisting of both reactive and nonreactive LC layers, which allows very thick gratings to be created with thin active LC layers. We demonstrate a tunable optical filter with a peak transmittance of 84% of unpolarized light, a minimum full width at half-maximum of 64 nm, and a maximum tuning range of 140 nm.