Crosstalk-reduced integrated digital optical switch

Details Crosstalk-reduced integrated digital optical switch Crosstalk-reduced integrated digital optical switch

1997-02-10

1999-03-30

Ngo, Hung N.

Optical waveguides

Directional optical modulation within an optical waveguide

Electro-optic

385 43, 385 45, 385 16, 385 22, 385 21, G02B 626

Patent

active

058898980

ABSTRACT:
Methods and apparatus for performing optical signal switching or other optical routing functions in an optical device or system, in which crosstalk induced by modal interference is suppressed by providing appropriate loss, gain and/or refractive index changes in different parts of a switch structure. An exemplary optical signal switch includes first and second branches each having a refraction-controlled section and an absorption-controlled section. An optical signal path over which an optical signal propagates in passing through the switch is selected to include a portion of at least one of the first and second branches, such that one of the first and second branches is a selected branch and the other branch is a non-selected branch. The refraction-controlled section of the selected branch is configured in a high effective refractive index state which allows the optical signal to propagate along at least a portion of the selected branch, while the refraction-controlled section of the non-selected branch is configured in a low effective refractive index state. The absorption-controlled section of the selected branch is configured in a low absorption state, while the absorption-controlled section of the non-selected branch is configured in a high absorption state to reduce crosstalk within the optical switch. An effective refractive index in a given refraction-controlled section may be provided using electro-refractive techniques such as the quantum-confined Stark effect (QCSE) or the Franz-Keldysh effect, or by carrier-induced effects such as carrier injection or carrier depletion. An absorption change in a given absorption-controlled section may be provided using electro-absorptive techniques or a gain-switching technique. The switch may be configured as a Y-branch switch, a directional coupler, or in other suitable configurations, and may be interconnected with other similar switches to construct 1.times.N, N.times.1, N.times.M and N.times.N switch arrays.

REFERENCES:
patent: 5400418 (1995-03-01), Pearson et al.
patent: 5418868 (1995-05-01), Cohen et al.
patent: 5452383 (1995-09-01), Takiguchi
H. Okayama and M. Kawahara, "Reducing of Voltage-Length Product for Y-branch Digtial Optical Switch," Journal of Lightwave Technology, vol. 11, No. 2, pp. 379-187, Feb. 1993.
W.K. Burns, "Shaping the Digital Switch," IEEE Photonics Technology Letters, vol. 4, No. 8, pp. 861-863, Aug. 1992.
M.N. Khan et al., "Design and Demonstration of Weighted-Coupling Digital Y-branch Optical Switches in InGaAs/InGaAlAs Electron Transfer Waveguides,"Journal of Lightwave Technology, vol. 12, No. 11, pp. 2032-2039, Nov. 1994.
K. Padmanabhan and A.N. Netravali, "Diplated Networks for Photonic Switching," IEEE Transactions on Communications, vol. COM-35, No. 12, pp. 1357-1365, Dec. 1987.
A. Sneh, J.E. Zucker and B.I. Miller, "Compact, Low-Crosswalk, and Low-Propagations-Loss Quantum-Well Y-branch Switches," IEEE Photonics Technology Letters, vol. 8, No. 12, pp. 1644-1646, Dec. 1993.
J.E. Zucket et al., "Quaternary Quantum Wells for Electro-Optic Intensisty and Phase Modulation at 1.3 and 1.55 .mu.m," Applied Physics Letters, vol. 54, pp. 10-12, Jan. 1989.
J.F. Vinchant et al., "InP/GaInAsP Guided-Wave Phase Modulators Based on Carrier-Induced effect: Theory and Experiment," Journal of Lightwave Technology, vol. 10, No. 1, pp. 63-70, Jan. 1992.
W.H. Nelson et al., "Wavelenghts and Polarization-Independent Large Angle InP/InGaAsP Digital Optical Switches With Extinction Ratios Exceeding 20 db," IEEE Photonics Technology Letters, vol. 6, No. 11, pp. 1332-1334, Nov. 1994.
K. Yamada et al., "Low Polarization Dependence (<0.3 db) in an Ea Modulator Using a Polyimide-Buried High-Messa Ridge Structure with an InGaAsP bulk absorption layer," Electronics Letters, vol. 31, No. 3, pp. 237-238, Feb. 1995.
D.J. Robbins, "Franz-Keldysh Effect in GaAsP," pp. 435-437 in Properties of Indium Phosphide, EMIS Datareviews Series No. 6, INSPEC, New York, Sep. 1990.
R.A. Soref and Kam-Yin Lau, "A Proposed Carrier-Induced Electrooptical Switch in III-V Quantum-Well Waveguide," Proceedings of the 21st Eur. Conf. on Opt. Comm. (ECOC '95), Brussels, 1995.
Patent Abstracts of Japan, vol. 014, No. 027 (P-992), Jan. 19, 1990, JP 01 267526 A (Fujitsu Ltd.).

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