Optical waveguides – With optical coupler – Particular coupling structure
Patent
1998-04-20
2000-11-28
Bovernick, Rodney
Optical waveguides
With optical coupler
Particular coupling structure
349 1, 349198, G02B 626
Patent
active
061545910
ABSTRACT:
A tunable optical filter comprises optical waveguides separated by a space filled with liquid crystal material which is oriented by an alignment layer or grating to form a Fabry Perot resonant cavity, where the resonant condition is set up by a reflective coating or grating in the optical waveguide, and the refractive index of the liquid crystal may be altered by the application of a voltage across the cavity by means of electrodes. The filter or an array of filters may be constructed using optical fibers between a substrate and a superstrate, preferably with the fibres being located by means of grooves formed in the substrate and superstrate, with individual electrodes in the space between aligned fibres enabling independent tuning of each filter, typically for use in wavelength division multiplexing communication systems. The liquid crystal molecules may be aligned parallel or perpendicular to the length of the fibres. In the perpendicular orientation, without a resonant cavity, the device can be used for polarisation state controller applications.
REFERENCES:
patent: 3975082 (1976-08-01), Winzer
patent: 4142776 (1979-03-01), Cherin et al.
patent: 4146299 (1979-03-01), Wellington et al.
patent: 4790634 (1988-12-01), Miller et al.
patent: 4923269 (1990-05-01), Healey
patent: 5015057 (1991-05-01), Rumbaugh et al.
patent: 5111321 (1992-05-01), Patel
patent: 5532854 (1996-07-01), Fergason
patent: 5781268 (1998-07-01), Liu et al.
Patent Abstracts of Japan, vol. 012, No. 203 (P-715), Jun. 11, 1988 & JP 63 005327A (Idemitsu Kosan Co. Ltd.) Jan. 11, 1988.
Yufei et al, "High-Speed Liquid Crystal Fiber Fabry-Perot Tunable Filter", IEEE Photonics Technology Letters, Sep. 1996, IEEE, USA, vol. 8, No. 9, ISSN 1041-1135, pp. 1190-1192.
Patel, "Electro-optic Switch Using a Liquid Crystal Fabry-Perot Filter", SPIE, vol. 1665, pp. 244-249 (1992) no month.
Sneh et al, "High-speed Wavelength Tunable Liquid Crystal Filter", IEEE Photonics Technology Letters, vol. 7, No. 4, Apr. 1995, pp. 379-381.
Madou et al, "Integrated Circuit Manufacturing Techniques Applied to Microfabrication", Handbook of Chemical and Biological Sensors, 1996, IOP Publishing, Bristol and Philadelphia no month.
MacLeod et al, "Thin Film Optical Filters", Adam Hilger Ltd., Bristol, 1986 no month.
Kashyap, "Photosensitive Optical Fibers: Devices and Applications", Optical Fiber Technology 1, pp. 17-34 (1994) no month.
Maze, "Determination of Nematic Liquid Crystal Elastic and Dielectric Properties from the Shape of a Capacitance-Voltage Curve", Mol. Cryst. Liq. Cryst., 1978, vol. 48, pp. 273-287 no month.
Shaver, "Alignment of Liquid Crystals by Surface Gratings", Technical Report, 538, Lincoln Laboratory, MIT, Oct. 31, 1979.
Schadt et al, "Optical Patterning of Multi-Domain Liquid-Crystal Displays with Wide Viewing Angles", Nature, vol. 381, May 16, 1996, pp. 212-215.
McCormick et al, "Microengineering Design and Manufacture Using the LIGA Process", Engineering Science and Education Journal, Dec. 1994, pp. 255-262.
Kitamura, "Computer Simulation of Director Profile in Two Dimensional Electric Field", SID PROC. 1994 International Workshop on Active Matrix LCDs, pp. 350-343 (1994).
Davies, "Finite-Element Modelling in 2-D of Nematic Liquid Crystal Structures", Electronics Letters, 14.sup.th Mar. 1996, vol. 32, pp. 582-583.
Welford et al, "Analysis of Electric Field Induced Deformations in a Nematic Liquid Crystal for any Applied Field", Mol. Cryst. Liq. Cryst., 1987, vol. 147, pp. 25-42 no month.
Jacobs, Chapter 2.5, "Liquid Crystals for Laser Applications", in Handbook of Laser Science and Technology, vol. IV, "Optical Materials (Pt. 2)", Ed. M.J. Weber, CRC Press Inc. Boca Raton, Florida, USA (1986) no month.
Bovernick Rodney
British Telecommunications public limited company
Kim Ellen E.
LandOfFree
Tunable optical device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Tunable optical device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tunable optical device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1734008