Development of optical vortex generator based on the polarization adress type spatial light modulation using photo-reactive liquid crystal polymers

2018 Fiscal Year Final Research Report

• Project/Area Number: 17K14663
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Electron device/Electronic equipment
• Research Institution: Nagaoka University of Technology
• Principal Investigator: Sakamoto Moritsugu 長岡技術科学大学, 工学研究科, 助教 (60757300)
• Project Period (FY): 2017-04-01 – 2019-03-31
• Keywords: 光渦 / 空間光変調 / ベクトルビーム / 光機能性液晶

Outline of Final Research Achievements

We proposed and developed new method for generating optical vortices by using three-dimensional twisted anisotropic structure fabricated in the uniaxially-aligned azo-dye-doped liquid crystal polymer composite by illuminating the vector beam. Alignment structure dependencies on optical vortex generation were numerically investigated, and we found that a purity and conversion efficiency of the optical vortex generated from the structure can be improved by changing the liquid crystal alignment distribution. Optical vortex generator was assembled by using scanning type polarization pattern illuminator consisting of polarization modulator and MEMS mirror. Generation of odd and even numbered order vortices were experimentally demonstrated. Also, we tried to accelerate response time of azo-dye-doped liquid crystal by investigating temperature dependency and composition ratio of materials.

Free Research Field

応用光学

Academic Significance and Societal Importance of the Research Achievements

その特異な光学的性質が注目され、近年飛躍的に応用の幅を広げている光渦の実験研究では、特異光波を発生させるための位相の空間制御デバイスが必要不可欠であり、とりわけその光制御の柔軟性・広帯域性・偏光選択性は特異光波の応用の可能性を拡大する基盤要素となる。本研究成果は、我々が提案する光機能性液晶材料を用いた偏光アドレス型の光渦発生装置が、これらの要素を併せ持つ位相制御装置として機能する事を理論的・実験的に示したものであり、今後の光渦の応用研究の発展に貢献するものと期待される。