本論文首次製作並研究由奈米粒子誘導垂直配向之染料摻雜液晶結合可全光調控與偏振無關之二維次波長波導模態共振濾波器。實驗結果顯示波導模態的共振波長可藉由依次照射紫外光和綠光，使得共振波長可逆地先紅位移再藍位移，進一步達成全光式調控。此與偏振無關之波導模態共振濾波器的共振波長可全光調控性主要乃歸因於奈米粒子誘導垂直配向液晶盒內之偶氮染料受紫外光照射後行光同素異構化反應，而從棒狀trans態轉變到彎曲狀cis態，引致液晶等溫地由垂直基板排列之向列相(折射率no)轉變為各向同性之isotropic態(折射率ni)；而之後照射綠光會使偶氮染料從cis態轉變回trans態的光同素異構化反應引致液晶等溫地從各向同性之isotropic狀態(折射率ni)逆轉變回垂直基板排列之向列相(折射率no)。此外，此可全光調控之共振濾波器尚有能夠重複性地多次來回調控且特性不會有所衰退。

The current work develops and investigates for the first time a two-dimensional (2D) all-optically tunable and polarization-independent guided-mode resonant (GMR) filter. This filter is based on a 2D sub-wavelength nanostructure, which incorporates a dye-doped liquid-crystal (LC) layer with a nanoparticle-doping-induced homeotropic (H) alignment. Experimental results show that the resonant wavelength of the GMR filter can be all-optically tuned to red-shift and then to blue-shift if the cell is illuminated successively by one ultraviolet (UV) and green beam. The all-optical and polarization-independent tunability of the filter is attributable to the H →isotropic (I) and I→H phase transitions, resulting in the variations of the LC refractive index from no→ni and ni→no, via the UV-beam-induced trans-cis and green-beam-induced cis-trans back isomerizations, respectively. In addition, such a filter can be all-optically tuned repeatedly for many times without decay or damage.

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