Probing the liquid crystal alignment interface and switching dynamics in a slab waveguide architecture

Henry G. Gotjen; Jakub Kolacz; Jason D. Myers; Jesse A. Frantz; Robel Y. Bekele; Jawad Naciri; Christopher M. Spillmann

doi:10.1117/12.2290618

23 February 2018 Probing the liquid crystal alignment interface and switching dynamics in a slab waveguide architecture

Henry G. Gotjen, Jakub Kolacz, Jason D. Myers, Jesse A. Frantz, Robel Y. Bekele, Jawad Naciri, Christopher M. Spillmann

Proceedings Volume 10526, Physics and Simulation of Optoelectronic Devices XXVI; 105262B (2018) https://doi.org/10.1117/12.2290618
Event: SPIE OPTO, 2018, San Francisco, California, United States

Abstract

A non-mechanical refractive laser beam steering device has been developed to provide continuous, two-dimensional steering of infrared beams. The technology implements a dielectric slab waveguide architecture with a liquid crystal (LC) cladding. With voltage control, the birefringence of the LC can be leveraged to tune the effective index of the waveguide under an electrode. With a clever prism electrode design a beam coupled into the waveguide can be deflected continuously in two dimensions as it is coupled out into free space. The optical interaction with LC in this beamsteerer is unique from typical LC applications: only the thin layer of LC (100s of nm) near the alignment interface interacts with the beam’s evanescent field. Whereas most LC interactions take place over short path lengths (microns) in the bulk of the material, here we can interrogate the behavior of LC near the alignment interface over long path lengths (centimeters). In this work the beamsteerer is leveraged as a tool to study the behavior of LC near the alignment layer in contrast to the bulk material. We find that scattering is substantially decreased near the alignment interface due to the influence of the surface anchoring energy to suppress thermal fluctuations. By tracking the position of the deflected beam with a high speed camera, we measure response times of the LC near the interface in off-to-on switching (~ms) and on-to-off switching (~100ms). Combined, this work will provide a path for improved alignment techniques, greater optical throughput, and faster response times in this unique approach to non-mechanical beamsteering.

Citation Download Citation

Henry G. Gotjen, Jakub Kolacz, Jason D. Myers, Jesse A. Frantz, Robel Y. Bekele, Jawad Naciri, and Christopher M. Spillmann "Probing the liquid crystal alignment interface and switching dynamics in a slab waveguide architecture", Proc. SPIE 10526, Physics and Simulation of Optoelectronic Devices XXVI, 105262B (23 February 2018); https://doi.org/10.1117/12.2290618

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available