We present an optically isotropic switchable microlens array (MLA) based on liquid crystals (LCs) using the Joule heating electrode structure. The LC molecules were initially aligned vertically on the lens and electrode surfaces. By applying voltage to the transparent electrodes, the temperature of the LC layer could be changed. Above the clearing point temperature of LCs, the LC layer shows an averaged refractive index that differs from the nematic state refractive index. The MLA could have switching characteristics by index matching between the LC layer and polymer lens structure. The proposed switchable MLA shows high light efficiency with truly optically isotropic properties.
© 2014 Optical Society of America
Original Manuscript: March 26, 2014
Revised Manuscript: May 1, 2014
Manuscript Accepted: May 5, 2014
Published: June 4, 2014
You-Jin Lee, Chang-Jae Yu, Jae-Ho Lee, Ji-Ho Baek, Youngsik Kim, and Jae-Hoon Kim, "Optically isotropic switchable microlens arrays based on liquid crystal," Appl. Opt. 53, 3633-3636 (2014)