Open AccessPolarized backlight with constrained angular divergence for enhancement of light extraction efficiency from wire grid polarizer
Author(s) -
Po Hung Yao,
Chi Jui Chung,
Cheng-Da Wu,
Cheng-Huan Chen
Publication year - 2012
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.004819
Subject(s) - polarizer , optics , backlight , materials science , polarization (electrochemistry) , rigorous coupled wave analysis , liquid crystal display , nanoimprint lithography , waveplate , optoelectronics , circular polarization , physics , diffraction grating , fabrication , wavelength , birefringence , laser , chemistry , alternative medicine , pathology , microstrip , medicine
Efficiency of liquid crystal displays highly depends on the amount of polarized light emerging from the backlight module. In this paper, a backlight architecture using a nanoimprint wire grid polarizer for polarization recycling is proposed and studied, in which the extraction efficiency of polarized light is the major concern. The backlight module is composed of the stack of a wire grid polarizer, a lenticular array and a light guide plate. The light guide plate features interleaving v-groove and trapezoidal ridge coated with aluminum on the top surface, and scattering dot array on the bottom. The angular divergence of emerging light from the light guide plate can be well constrained so as to exploit the angular range with the best transmission of polarized light for the wire grid polarizer. The prototype of a 2.5-inch module has demonstrated an angular divergence of 48°. The overall extraction efficiency of polarized light enhanced by 21% and uniformity of 76% have been achieved.