Optical waveguides – With optical coupler – Switch
Reexamination Certificate
2001-03-19
2004-09-07
Sanghavi, Hemang (Department: 2874)
Optical waveguides
With optical coupler
Switch
C385S011000, C385S015000, C385S024000, C398S001000, C398S052000, C398S053000, C398S101000, C398S102000
Reexamination Certificate
active
06788839
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to all-optical switches and interferometers used for routing data.
2. Background Information
Conventional wavelength division multiplexing (WDM) systems efficiently use bandwidth in existing fiber-optic telecommunication infrastructures. Such systems provide point-to-point optical transmission at high aggregate rates (>100 Gb/s) without compromising on high performance. Future requirements of digital communication networks indicate that increased data-rate capacity is critical to a service provider's success in the market. Ultimately, all-optical networks will replace today's optical/electrical networks that suffer from the bottlenecking effects of optical-to-electrical-to-optical conversions due to the limited capacity of electronic devices. Devices that can optically process data without converting it to an electronic format are essential to this network capacity evolution.
Several forecasts have predicted that there will be a tremendous growth in the sensor market. In contrast to the classical sensors based largely upon the measurement of electrical parameters such as variable resistance or capacitance, modern sensors make use of a variety of novel phenomena. More importantly, these sensors are directly suitable for digital control and also have a degree of smartness incorporated in them to combat problems of nonlinearity and long term drift. Several key technologies are likely to play a major role in the sensors of the future. Microelectromechanical (MEM) sensors have tremendous potential as smart sensors. Fiber optics based sensors are also emerging as a viable and competitive technology. While many types of stand alone sensors are available, only some of them can be considered for integration with smart structures. Among these, fiber optic sensors are in the forefront in their choice for incorporation into materials and structures made of carbon and glass fiber reinforced polymer composites.
The advantages of fiber optic sensors (FOS) include freedom from EMI, wide bandwidth, compactness, geometric versatility and economy. In general, FOS is characterized by high sensitivity when compared to other types of sensors. FOS is also passive in nature due to the dielectric construction. Many signal processing devices (e.g., splitters, combiners, multiplexers, filters, delay lines) can also be made of fiber elements, thus enabling the realization of an all-fiber measuring system. Recently, photonic circuits (Integrated Optics) has been proposed as a single chip optical device or signal processing element which enables miniaturization, batch production, economy and enhanced capabilities.
A fiber optic sensor in general consists of a source of light, a length of sensing (and transmission) fiber, a photodetector, demodulation, processing and display optics and the required electronics. Interferometric (phase) sensors are based on the detection of changes in the phase of light emerging out of a single mode fiber. Interferometric fiber optic sensors are by far the most commonly used sensors since they offer the best performance.
A deficiency with prior art interferometers is that they cannot be “time tuned” to handle different switching requirements. Presently, a different interferometer must be used for different data stream routing applications.
BRIEF SUMMARY OF THE INVENTION
The present invention provides for the use of an integrated optical coupler (e.g., a quadrature coupler) at the output of a demultiplexer device which transforms the functionality of the component into an integrated all-optical routing (switching) element.
The present invention also provides for the use of one or more variable time delay elements that enable the selection of desired bits or groups of bits in an all-optical data packet or all-optical data burst for routing onto one of two possible paths of the optical coupler.
The present invention also provides for the monolithic integration of a variety of optical device structures construing the present invention, which together may be used to produce superior performance and increased utility over the prior art.
REFERENCES:
patent: 5060305 (1991-10-01), Prucnal et al.
patent: 5073980 (1991-12-01), Prucnal et al.
patent: 5173956 (1992-12-01), Hayes
patent: 5493433 (1996-02-01), Prucnal et al.
patent: 5517022 (1996-05-01), Bock et al.
patent: 5555119 (1996-09-01), Lewis
patent: 5825519 (1998-10-01), Prucnal
patent: 5841560 (1998-11-01), Prucnal
patent: 5917979 (1999-06-01), Prucnal
patent: 5926496 (1999-07-01), Ho et al.
patent: 5999293 (1999-12-01), Manning
patent: 6188511 (2001-02-01), Marcenac et al.
Nakamura et al., “168 Gbps Error-Free Demultiplexing with Hybrid-Integrated Symmetric Mach-Zehnder All-Optical Switch,” Optical Fiber Conference 2000 Technology Digest, pp. 81-83, (Mar., 2000).
Sokoloff et al., “A Terahertz Optical Asymmetric Demultiplexer (TOAD),” IEEE Photonics Technology Letters, vol. 5, No. 7, pp. 787-790 (Jul., 1993).
Kang et al., “Ultrafast Optical Time Demultiplexers Using Semiconductor Optical Amplifiers,” International Journal of High Speed Electronics and Systems, vol. 7, No. 1, pp. 125-151 (1996).
Glesk et al., “Demonstration of Ultrafast All-Optical Packet Routing,” Electronics Letters, vol. 33, No. 9, pp. 794-795 (Apr., 1997).
Levy et al., “Fabrication of Ultracompact 3-db 2 x 2 MMI Power Splitters,” IEEE Photonics Technology Letters, vol. 11, No. 8, pp. 1009-1011 (Aug., 1999).
Chin et al., “Design and Modeling of Waveguide-Coupled Single-Mode Microring Resonators,” Journal of Lightwave Technology, vol. 16, No. 8, pp. 1433-1446 (Aug., 1998).
International Preliminary Examination Report (IPER) for PCT/US02/06850, mailed Mar. 26, 2003, 11 pages.
Leuthold, J. et al., “All-Optical Mach-Zehnder Interferometer Wavelength Converters and Switches with Integrated Data-and Control-Signal Separation Scheme,” Journal of Lightwave Technology, IEEE. vol. 17, No. 6, Jun. 1999, pp. 1056-1065.
International Search Report for PCT Application No. PCT/US02/06850, mail date Jul. 18, 2002, 3 pages.
Tajima, K. et al: “Ultrafast Semiconductor All-Optical Switch Based on Highly Efficient Incoherent Nonlinearity with Slow Relaxation” Optoelectronics Devices and Technologies, Mita Press, Tokyo, JP, vol. 10, No. 4, Dec. 1, 1995, pp. 505-514.
Riza, N.A.: “Acousto-optically Switched Optical Delay Lines”, Optics Communications, North-Holland Publishing Company, Amsterdam, NL, vol. 145, No. 1-6, 1998, pp. 15-20.
Porte, H. et al.: An LiNbO3Integrated Coherence Modulator, Journal of Lightwave Technology, IEEE. New York, US. vol. 10, No. 6, Jun. 1, 1992, pp. 760-766.
Akin Gump Strauss Hauer & Feld & LLP
General Instrument Corporation
Sanghavi Hemang
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