Optical: systems and elements – Deflection using a moving element – Using a periodically moving element
Reexamination Certificate
2001-08-31
2002-10-29
Pascal, Leslie (Department: 2633)
Optical: systems and elements
Deflection using a moving element
Using a periodically moving element
C359S199200, C359S566000, C359S573000, C385S017000
Reexamination Certificate
active
06473211
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to interconnection and switching systems, and, more particularly, to optical switching and interconnect systems which incorporate the use of diffractive optics and noise suppressors.
BACKGROUND OF THE INVENTION
With the advent of substantial new uses for high bandwidth digital and analog electro-optic systems, there exists a greater need to effectively control the routing and switching capability of electro-optic or optical signals from among many possible paths. This is especially true in digital computing systems where signals must be routed among processors; in analog systems such as phased array radar; and in the switching of high bandwidth optical carriers in communication systems. However, it should be realized that these are just several of numerous electro-optic systems which require the use of an optical switching or routing mechanism.
In many current and future systems light beams are modulated in a digital and/or analog fashion and used as “optical carriers” of information. There are many reasons why light beams or optical carriers are preferred in these applications. For example, as the data rate required of such channels increases, the high optical frequencies provide a tremendous improvement in available bandwidth over conventional electrical channels such as formed by wires and coaxial cables. In addition, the energy required to drive and carry high bandwidth signals can be reduced at optical frequencies. Further, optical channels, even those propagating in free space (without waveguides such as optical fibers) can be packed closely and even intersect in space with greatly reduced crosstalk between channels. Finally, operations that are difficult to perform in the lower (e.g., radio) frequencies such as time shifting for phased array applications can often be performed more efficiently and compactly using optical carriers.
A common problem encountered in many applications in which high data rate information is modulated on optical carrier beams is the switching of the optical carriers from among an array of channels. These differing optical channels may represent, for example, routes to different processors, receiver locations, or antenna element modules. One approach to accomplish this switching is to extract the information from the optical carrier, use conventional electronic switches, and then re-modulate the optical carrier in the desired channel. However from noise, space, and cost perspectives it is more desirable to directly switch the route of the optical carrier directly from the input channel to the desired channel.
It is therefore an object of this invention to provide an optical crossbar switching and/or routing system that can independently route each and every optical carrier from an array of input channels to any of an array of output channels.
It is another object of this invention to provide an optical crossbar switching and/or routing system that provides for a compact planar geometry.
It is further an object of this invention to provide an optical switching and/or routing system that is capable of full or partial broadcast from a single or subset of inputs to selected outputs.
It is still further an object of this invention to provide an optical crossbar switching and/or routing system that provides a low loss one-to-one optical interconnection from a set of input channels to a set of output channels.
SUMMARY OF THE INVENTION
The present invention overcomes problems associated with insertion loss, size and compactness, switch isolation, switching speed, that may be present in current optical switching systems. The present invention includes switching and/or routing devices that use high efficiency switched diffractive gratings to form optical switching, interconnection, and routing networks. The diffractive gratings are electrically, optically, or otherwise switchable, so that they may be turned “off” (a state in which the incident beam is undeviated) or “on” (a state in which the incident beam is diffracted to a new direction). All of the above switching and/or routing operations being accomplished in “free space.”
Further, the various systems of this invention are essentially planar, and with the use of micro-optical channels, the present invention has the potential to be packaged into small form factors as would be required for use in many computing applications.
For a better understanding of the present invention, together with other and further objects, reference is made to the following description taken in conjunction with the accompanying drawings, and its scope will be pointed out in the appended claims.
REFERENCES:
patent: 4013000 (1977-03-01), Kogelnik
patent: 4236783 (1980-12-01), Hepner et al.
patent: 5009477 (1991-04-01), Alferness et al.
patent: 5133027 (1992-07-01), Funazaki et al.
patent: 5218198 (1993-06-01), Bristow et al.
patent: 5255332 (1993-10-01), Welch et al.
patent: 5491762 (1996-02-01), Deacon et al.
patent: 5581642 (1996-12-01), Deacon et al.
patent: 5692077 (1997-11-01), Stone et al.
patent: 5706383 (1998-01-01), Malcuit et al.
patent: 5771320 (1998-06-01), Stone
patent: 5892864 (1999-04-01), Stoll et al.
patent: 5982515 (1999-11-01), Stone et al.
patent: 6072923 (2000-06-01), Stone
patent: WO96/08932 (1996-03-01), None
R. T. Ingwall and T. Adams, “Hologram:Liquid Crystal Composites,” Proceedings of the SPIE 1555, 279-290 (1991).
Y-T Huang, “Polarization Selective Volume Holograms,” Applied Optics, 33, 2115 (1994).
Y-T Huang, “Polarization—independent Optical switch Composed of Holographic Optical Elements,” Optics Letters, vol. 20, No. 1, 1198-1200 (May 15, 1995).
T. J. Bunning, L. V. Natarajan, V. P. Tondiglia, R. L. Sutherland, D. L. Vezie, and W. A. Adams, “Morphology of Reflection Holograms Formed In Situ Using Polymer-Dispersed Liquid Crystals,” Polymer [Polymer Communications] 37, 3147 (1996).
T. J. Cloonan, “Free-Space Optical Implementation of a Feed-Forward Crossbar Network,” Applied Optics 29, 2006, see Fig. 10 in particular, (1990).
M. S. Malcuit and T. W. Stone, “Optically Switched Volume Holographic Elements,” Optics Letters, 20, 1328 (Jun. 1, 1995).
T. Stone, M. Malcuit, and J. Kleinfeld,“Switched Grating Devices For Phased Array Applications,” Proceedings of the SPIE, 2844, 182 (1996).
T. Stone, M. Malcuit, and J. Kleinfeld, and J. Kralik, “Micro-Optic Photonic Time Shifters Based On Switched Gratings,” Proceedings of the SPIE, 3160, 17 (1997).
T. Stone, J. Kralik, and M. Malcuit, “Characteristics of Photonic Time Shifters Based on Switched Gratings,” Proceedings of the SPIE, 3463, (Jul 21-22, 1998).
K. Tanaka, K. Kato, M. Date, and S. Sakai, “Optimization of Holographic PDLC for Reflective Color Display Applications,” Society of Information Display 1995 Digest, Paper 18.1, 267 (May 1995).
R. L. Sutherland, L. V. Natarajan, V. P. Tondiglia, T. J. Bunning, and W. W. Adams, “Switchable Holograms in New Photopolymer-Liquid Crystal Composite Materials,” Proceedings of the SPIE, 2404, 132 (3/1995).
H. Okayama, M. Kawahara, “Ti: LiNbO3Digital Optical Switch Matrices,” Electronics Letters 29, 765 (1993).
T. Kirihara, M. Ogawa, H. Inoue, H. Kodera, K. Ishida, “Lossless And Low-crosstalk Characteristics In An InP-Based 4 ×4 Optical Switch With Integrated Single-stage Optical Amplifiers,” IEEE Photonics Technology Letters 6, 218 (1994).
P. C. Huang, W. E. Stephens, T. C. Banwell, L. A. Reith, “Performance Of 4×4 Optical Crossbar Switch Utilizing Acousto-Optic Deflector,” Electronics Letters 25, 252, see first Figure in particular, (1989).
Y. Wu, L. Liu, Z. Wang, “Optical Crossbar Elements USed For Switching Networks,” Applied Optics 33, 175(1994).
K. Hirabayashi, T. Yamamoto, M. Yamaguchi, “Free-space Optical Interconnections With Liquid-crystal Microprism Arrays,” Applied Optics 34, 2571 (May 10, 1995).
T. Sakano, K. Kimura, K. Noguchi, N. Naito, “256×256 Turnover-type Free-space Multichannel Optical Switch Based On Polarization Control Using Liquid-crystal Spatial Light Modulators,” Applied Optics 34, 2581 (May 10
Agilent Technologie,s Inc.
Bello Agustin
Pascal Leslie
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