Title :
A varifocal lens using an electrooptic KTa1−xNbxO3 crystal with a microsecond order response time
Author :
Imai, Tetsuro ; Inagaki, Takahiro ; Miyazu, Jun ; Kawamura, Sadao ; Kobayashi, Junya
Author_Institution :
NTT Photonics Labs., Nippon Telegraph & Telephone Corp., Atsugi, Japan
Abstract :
We report a varifocal lens made of potassium tantalate niobate (KTa1-xNbxO3, KTN) that exhibits a huge second-order EO effect, namely the Kerr effect. The lens consists of a KTN block on which four strip film electrodes are mounted. A voltage applied with these electrodes forms an electric field distribution, modulates the refractive index of the KTN block, and bends light rays. The lens power can be controlled from zero to 1.4 m-1. By inserting the KTN lens in front of a fixed glass lens with a focal length of 250 mm, we were able to move the focus by 87 mm. It was confirmed experimentally that the focus of the lens moved as theoretically predicted with a response time of faster than 2 μs. Owing to the anisotropy of the Kerr effect, the lens is polarization dependent. We also present a technique for eliminating this dependence.
Keywords :
Kerr electro-optical effect; lenses; niobium compounds; potassium compounds; refractive index; tantalum compounds; Kerr effect; electric field distribution; electrooptic crystal; light rays; microsecond order response time; refractive index; size 250 mm; strip film electrodes; varifocal lens; Electrodes; Glass; Integrated optics; Lenses; Liquid crystals; Optical polarization; Optical refraction; KTN; electrooptic effect; electrostrictive effect; potassium tantalate niobate; varifocal lens;
Conference_Titel :
Electronics Packaging (ICEP), 2014 International Conference on
Conference_Location :
Toyama
Print_ISBN :
978-4-904090-10-7
DOI :
10.1109/ICEP.2014.6826769