[15p-C42-1~11] 3.2 Equipment optics and materials

[15p-C42-9] Manufacture and Beam Deflection Effect of Fresnel Liquid Crystal Defrector

〇GIICHI SHIBUYA¹, Shohei Yamano¹, Hiroyuki Yoshida¹, Masanori Ozaki¹ (1.Osaka Univ.)

Keywords:liquid crystal, Fresnel, deflector

Liquid crystal (LC) deflectors are actively studied in prospect of developing smart optical devices with tunability. However, conventional liquid crystal deflector has a restriction of beam deflection angle from the limitation of the thickness of liquid crystal layer. We have tried to expand the deflection angle by the application of Fresnel structure into the conventional LC device. Novel structure of thin films and interdigitated electrodes induces a saw-tooth distribution of refractive index in the LC material sealed between the planar transparent substrates. Manufacturing sample of LC deflector with the 0.2 mm pitch of the interdigitated electrode and the 30 μm thickness of the LC layer was prepared for the optical experiment. The deflection angle of the beam incident normally on the device increased continuously with an increase in the applied voltage. Because of the Fresnel structure in which the wavefront is made periodic in small segments, a larger maximum deflection angle was achieved compared to the device without the Fresnel structure. The observed maximum deflection angle was achieved to ±1.3 deg. which was large enough to apply for the optical image stabilizer without any moving parts.