ELECTRICALLY-CONTROLLABLE LIQUID-CRYSTAL POLARIZING FILTER FOR ELIMINATING REFLECTED LIGHT

Citation
H. Fujikake et al., ELECTRICALLY-CONTROLLABLE LIQUID-CRYSTAL POLARIZING FILTER FOR ELIMINATING REFLECTED LIGHT, Optical review, 5(2), 1998, pp. 93-98
Citations number
6
Language
INGLESE
art.tipo
Review
Categorie Soggetti
Optics
Journal title
ISSN journal
1340-6000
Volume
5
Issue
2
Year of publication
1998
Pages
93 - 98
Database
ISI
SICI code
1340-6000(1998)5:2<93:ELPFFE>2.0.ZU;2-9
Abstract
A high-speed controllable polarizing filter has been developed to elim inate obstructive polarized light reflected from glass and watery surf aces for image pickup in video media program producing and marine dyna mic remote sensing. In this device, the polarization plane of incident light is rotated through 0 degrees, 45 degrees, 90 degrees or 135 deg rees by an electrically-controllable polarization rotator composed of 45 degrees and 90 degrees twisted nematic liquid crystal cells, and th e polarization component of reflected light is absorbed by a fixed pol arizing film. It selectively absorbs more than 80% of incident white l ight linearly polarized in an arbitrary direction. With the drastic re duction of reflected light, the object images hidden by the bright ref lected light are clearly captured in real time. Another type of polari zing filter, using a guest-host liquid crystal cell instead of the pol arizing film, controls light absorption as well as polarization angle.