The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 09, 1995
Filed:
Jun. 01, 1993
Jayantilal S Patel, Red Bank, NJ (US);
Yaron Silberberg, West Windsor Township, Mercer County, NJ (US);
Bell Communications Research, Inc., Livingston, NJ (US);
Abstract
A liquid-crystal optical beam switch comprising: a first birefringent layer (14) which divides an input beam (24) into its two polarization components; a first segmented twisted nematic liquid-crystal polarization modulator (16), the segments (30,32) of which rotate one of the polarization beams by 90.degree. but not the other so they both have the same polarization state and which polarization state depends on the biasing state of a two-state biasing source (33); a second birefringent layer 18 which displaces the beams in a direction perpendicular to that produced by the first birefringent layer if they are of one polarization but do not displacement them if they are of the other polarization dependent upon the biasing state; a second segmented twisted nematic liquid-crystal polarization modulator (20) the segments (50,52) of which are oppositely biased from the segments of the first liquid-crystal modulator to thereby restore the original polarization difference; and a third birefringent layer (22) which, acting conversely to the first birefringent layer, recombines the beams into one of two output beams (58,64) dependent on the biasing state. A further stage of switching is provided by a fourth birefringent layer (104) having twice the thickness of and the same displacement direction as the second birefringent layer and by a separately switched associated unsegmented liquid-crystal polarization modulator (92).