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`UNITED STATES PATENT AND TRADEMARK OFFICE
`_______________
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`_____________
`
`CISCO SYSTEMS, INC.,
`Petitioner
`
`———————
`
`IPR2023-01047
`U.S. Patent No. 7,921,323
`_______________
`DECLARATION OF DANIEL BLUMENTHAL
`UNDER 37 C.F.R. § 1.68 IN SUPPORT OF PETITION
`FOR INTER PARTES REVIEW
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`Ex. 1003
`CISCO SYSTEMS, INC. / Page 1 of 111
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`Declaration of Daniel Blumenthal
`Inter Partes Review of U.S. 7,921,323
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`TABLE OF CONTENTS
`INTRODUCTION ............................................................................................ 4
`I.
`QUALIFICATIONS AND PROFESSIONAL EXPERIENCE ....................... 7
`II.
`III. LEVEL OF ORDINARY SKILL IN THE ART ............................................ 14
`IV. RELEVANT LEGAL STANDARDS ............................................................ 15
`V.
`BACKGROUND ............................................................................................ 16
`VI. OVERVIEW OF THE ’323 PATENT ........................................................... 36
`A.
`Summary of the Patent ......................................................................... 36
`B.
`Prosecution History of the ’323 Patent ................................................ 37
`VII. CLAIM CONSTRUCTION ........................................................................... 38
`VIII. CLAIMS 27-28, 31, AND 33 ARE UNPATENTABLE ............................... 43
`IX. GROUND 1: HARTSELL RENDERS OBVIOUS CLAIMS 27-28, 31,
`AND 33 ........................................................................................................... 45
`A. Detailed Analysis of Claims ................................................................. 45
`1.
`Claim 27 ..................................................................................... 45
`2.
`Claim 28 ..................................................................................... 78
`3.
`Claim 31 ..................................................................................... 79
`4.
`Claim 33 ..................................................................................... 83
`X. GROUND 2: HARTSELL AND HAUCK RENDERS OBVIOUS
`CLAIMS 27-28, 31, AND 33 ......................................................................... 84
`A.
`Reasons to Combine Hartsell and Hauck ............................................. 84
`B.
`Detailed Analysis of Claims ................................................................. 85
`1.
`Claim 27 ..................................................................................... 85
`2.
`Claim 28 ..................................................................................... 92
`3.
`Claim 31 ..................................................................................... 92
`4.
`Claim 33 ..................................................................................... 93
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`Declaration of Daniel Blumenthal
`Inter Partes Review of U.S. 7,921,323
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`XI. GROUNDS 3 AND 4: THE COMBINATION OF HARTSELL AND
`RAJ AND THE COMBINATION OF HARTSELL, HAUCK, AND
`RAJ RENDER OBVIOUS CLAIMS 27-28, 31, AND 33 ............................. 93
`A.
`Reasons to Combine Hartsell and Raj .................................................. 93
`B.
`Detailed Analysis of Claims ................................................................. 94
`1.
`Claim 27 ..................................................................................... 94
`2.
`Claim 28 ................................................................................... 105
`3.
`Claim 31 ................................................................................... 107
`4.
`Claim 33 ................................................................................... 110
`XII. CONCLUSION ............................................................................................. 111
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`I.
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`Declaration of Daniel Blumenthal
`Inter Partes Review of U.S. 7,921,323
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`I, Daniel Blumenthal, do hereby declare as follows:
`INTRODUCTION
`1.
`I am making this declaration at the request of Cisco Systems, Inc. in the
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`matter of the Inter Partes Review of U.S. Patent No. 7,921,323 (“the ’323 Patent”)
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`to Yancey et al.
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`2.
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`I am being compensated for my work in this matter at my standard
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`hourly rate. I am also being reimbursed for reasonable and customary expenses
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`associated with my work and testimony in this proceeding. My compensation is not
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`contingent on the outcome of this matter or the specifics of my testimony.
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`3.
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`I have been asked to provide my opinions regarding whether the subject
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`matter of claims 27-28, 31, and 33 (“the Challenged Claims”) of the ’323 patent
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`would have been obvious to a person having ordinary skill in the art (“POSITA”) at
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`the time of the alleged invention, in light of the prior art. It is my opinion that the
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`Challenged Claims would have been obvious to a POSITA.
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`4.
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`In the preparation of this declaration, I have relied on:
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`the ’323 patent, Ex. 1001;
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`the prosecution history of the ’323 patent (“’323 File History”),
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`•
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`•
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`Ex. 1002;
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`•
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`U.S. Patent Publication No. 2002/0059274 to Hartsell et al.
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`(“Hartsell”), Ex. 1005;
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`Declaration of Daniel Blumenthal
`Inter Partes Review of U.S. 7,921,323
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`•
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`•
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`U.S. Patent No. 6,496,291 to Raj et al. (“Raj”), Ex. 1007; and
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`Scott Hauck, “The Roles of FPGA’s in Reprogrammable
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`Systems,” Proceedings of the IEEE, vol. 86, no. 4 (April 1998).
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`5.
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`In forming the opinions expressed below, I have considered the
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`documents listed above; the relevant legal standards, including the standard for
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`obviousness; and my own knowledge and experience based upon my work in the field
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`of field of communication networks as described below, as well as portions of the
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`following additional materials:
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`U.S. Patent No. 6,907,595 to Curd et al., Ex. 1006;
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`Microsoft Press, Computer Dictionary, Third Edition, 1997,
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`•
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`•
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`Ex. 1009;
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`•
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`“Virtex-II Pro™ Platform FPGAs: Introduction and Overview,”
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`Xilinx, March 24, 2003, Ex. 1010;
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`•
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`“Virtex-II Pro™ Platform FPGA User Guide,” Xilinx, June 30,
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`2003, Ex. 1011;
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`•
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`•
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`•
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`U.S. Patent No. 7,680,054 to Acharya, Ex. 1013;
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`U.S. Patent No. 7,039,057 to Acharya et al., Ex. 1014;
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`U.S. Patent No. 7,382,787 to Barnes et al., Ex. 1015;
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`•
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`L. Kazovsky et al., “Optical Fiber Communication Systems,”
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`1996, Ex. 1021;
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`•
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`J. Goodman, “Optical Interconnection in Microelectronics,” SPIE
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`Vol. 456 Optical Computing, 1984, Ex. 1022;
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`•
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`R. Michalzik, “Optical Backplanes, Board and Chip
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`Interconnects,” Fiber Optic Data Communication: Technological Trends and
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`Advances, 2002, Ex. 1023;
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`•
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`K. Hahn et al., “Gigabyte/s Data Communications with the POLO
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`Parallel Optical Link,” Electronics Components and Technology Conference,
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`1996, Ex. 1024;
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`•
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`D. Blumenthal, “Routing Packets with Light,” Scientific
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`American, Jan. 2001, Ex. 1025;
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`•
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`M. O’Mahony et al., “The Application of Optical Packet
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`Switching in Future Communication Networks,” IEEE Communications
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`Magazine, Mar. 2001, Ex. 1026;
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`•
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`N. Sherwani et al., “Introduction to Multichip Modules,” 1995,
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`Ex. 1027;
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`•
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`C. Maxfield, “The Design Warrior’s Guide to FPGAs: Devices,
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`Tools, and Flows,” 2004, Ex. 1028;
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`•
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`U.S. Patent No. 5,898,801 to Braun , Ex. 1029;
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`J. Lockwood et. al., “Reprogrammable Network Packet
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`Processing on the Field Programmable Port Extender (FPX),” FPGA 2001
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`(Feb. 11-12, 2001), Ex. 1031
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`•
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`•
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`U.S. Patent No. 6,891,397 to Brebner, Ex. 1032; and
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`U.S. Patent Publication No. 2004/0249964 to Mougel, Ex. 1033.
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`6.
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`Unless otherwise noted, all emphasis in any quoted material has been
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`added. Claim terms are italicized.
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`II. QUALIFICATIONS AND PROFESSIONAL EXPERIENCE
`7. My complete qualifications and professional experience are described
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`in my Curriculum Vitae, a copy of which can be found in Exhibit 1004. The following
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`is a brief summary of my relevant qualifications and professional experience.
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`8. My education and my experience in this and related areas span 41 years
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`of professional and academic experience.
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`9.
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`I am considered a pioneer in optical communications, packet switching,
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`and integrated photonic and optical devices and several other optical application
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`areas, each of which have some relationship to the subjects involved.
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`10.
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`I received a B.S. degree in Electrical Engineering from the University
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`of Rochester, Rochester, New York, in 1981, an M.S. degree in Electrical
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`Engineering from Columbia University, New York, in 1988, and a Ph.D. degree in
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`Declaration of Daniel Blumenthal
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`Electrical Engineering from the University of Colorado, Boulder, in 1993. From 1981
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`until 1984, I worked as an engineer at StorageTek, Louisville, Colorado, on one of
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`the world’s first optical data storage products. From 1984 to 1985 I worked as a
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`Senior Engineer at Sievers Research in the area of optical spectroscopy. From 1985
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`- 1988, I worked at Columbia University as a research engineer in the Center for
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`Telecommunications, in the area of ultra-fast optical fiber communications and
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`optical packet switching while pursuing at the same time my Masters degree in
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`Electrical Engineering. While at Columbia I built one of the world’s first optical
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`packet switches. The Telecommunications Center was one of the National Science
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`Foundation centers of excellence
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`that
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`launched
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`the modern
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`form of
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`telecommunications networks layered communications and spawned a wide range of
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`research from multi-media communications, to packet communications, to optical
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`communications and network layered architectures. From 1988 to 1990 I worked in
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`the Distributed Computing Systems Laboratory at the University of Pennsylvania.
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`From 1990 I worked as a graduate student researcher while pursuing my PhD in the
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`Optoelectronic Computing Center at the University of Colorado Boulder, where I
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`built one of the world’s first self-routing optical packet switches. From 1993 to 1997,
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`I was an assistant professor in the School of Electrical and Computer Engineering at
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`the Georgia Institute of Technology in Atlanta where I built a program in optical
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`communications and packet switching and my focus on research in optical packet
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`switching, optical network, optical wavelength conversion using semiconductor
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`optical amplifiers (SOAs), optical label switching and other related technologies led
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`to groundbreaking innovations in these areas.
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`11.
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`I am currently a Distinguished Professor in the Department of Electrical
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`and Computer Engineering at the University of California, Santa Barbara (UCSB). I
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`also serve as the Director of the Terabit Optical Ethernet Center (TOEC). My research
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`areas are in optical communications, photonic packet switching and all-optical
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`networks, all-optical wavelength conversion and
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`regeneration, ultra-fast
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`communications, indium phosphide Photonic Integrated Circuits (PICS) and nano-
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`photonic device technologies.
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`12.
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`I have authored or co-authored over 525 journal and conference
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`publications, hold 23 issued US patents, and am a co-author of one book, Tunable
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`Laser Diodes and Related Optical Sources (New York: IEEE–Wiley, 2005) as well
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`as seven other book chapters. I have published two invited papers in the prestigious,
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`broadly read, Proceedings of the IEEE and one invited paper in the prestigious
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`broadly read Scientific American magazine. The Proceedings of the IEEE is the
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`leading IEEE journal that provides in-depth review, survey, and tutorial coverage of
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`the technical developments across all engineering areas including electronics,
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`electrical and computer engineering, and computer science and is ranked as one of
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`the top journals by Impact Factor, Article Influence Score and serves as a resource
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`for engineers around the world. The first invited paper published in the Proceedings
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`was entitled “Photonic Packet Switches: Architectures and Experimental
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`Implementations” in the 1994 special issue on Optical Computing Systems and is the
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`highest cited paper in that special issue. The second invited paper in the Proceedings
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`is in the 2018 Special Issue on Silicon Photonics entitled “Silicon Nitride in Silicon
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`Photonics.” In 2000, I was invited to write a seminal paper entitled “Routing Packets
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`with Light,” that appeared in the January 2001 issue of Scientific American, a popular
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`science magazine that has had many famous scientists contribute, and with 170 years
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`is the oldest continuously published monthly magazine in the United States.
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`13.
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`I have served as the principal investigator for multiple large-scale
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`research programs funded by the Defense Advanced Research Projects Agency
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`(DARPA).
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`14. At the national scale, I contributed to multiple US based fiber optic
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`Internet backbone projects. I served on the Board of Directors for National
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`LambdaRail (NLR), a nation-wide fiber backbone, from 2003-2010. I was an elected
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`Board Member for the Internet-2 Architecture & Operations Advisory Council from
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`2008-2012.
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`15.
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`In addition to my industry experience at StorageTek and Sievers, I have
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`co-founded two companies, Packet Photonics, Inc. and Calient Technologies, Inc.
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`Packet Photonics, Inc. provided network and data center operators with photonic
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`integrated wavelength tunable solutions to implement, install, operate, and maintain
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`networks. Calient Technologies, Inc. provides software enabled adaptive MEMS
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`mirror based photonic switching systems that enable dynamic optical layer switching
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`and optimization.
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`16.
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`I was elected as a Fellow of the National Academy of Inventors (NAI)
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`in 2017. From the NAI website: “The program has 1,060 Fellows worldwide
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`representing more than 250 prestigious universities and governmental and non-profit
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`research institutes. Collectively, the Fellows hold more than 38,000 issued U.S.
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`patents, which have generated over 11,000 licensed technologies and companies, and
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`created more than 36 million jobs. In addition, over $1.6 trillion in revenue has been
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`generated based on NAI Fellow discoveries. With the induction of the 2018 class,
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`there are now more than 125 presidents and senior leaders of research universities
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`and non-profit research institutes, 502 members of the National Academies of
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`Sciences, Engineering, and Medicine; 40 inductees of the National Inventors Hall of
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`Fame, 57 recipients of the U.S. National Medal of Technology and Innovation and
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`Declaration of Daniel Blumenthal
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`U.S. National Medal of Science, 34 Nobel Laureates, 3 Queen Elizabeth Prize for
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`Engineering recipients, 304 AAAS Fellows, 200 IEEE Fellows, and 164 Fellows of
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`the American Academy of Arts & Sciences, among other awards and distinctions.”
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`17.
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`In 2020 I was the recipient of the prestigious Optical Society of America
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`(now OPTIFCA) C.E.K. Mees medal. The medal was established in 1961 in memory
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`of charter member C. E. K. Mees, to recognize achievements that exemplifies the
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`thought that "optics transcends all boundaries". Prior to 2017 the medal was presented
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`every two years since 1962, and it has been presented annually since 2017. Former
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`recipients of the medal include Charles H. Townes, inventor of the laser and Nobel
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`Laureate.
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`18.
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`I am a Fellow of the IEEE (only 0.1% of the world-wide membership
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`can be elected as Fellows in a given year: “According to IEEE Bylaw I-305.5, "The
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`total number of Fellow recommendations in any one year must not exceed one-tenth
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`of one percent of the IEEE voting membership on record as of 31 December of the
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`year preceding.") and a Fellow of the Optical Society of America (OSA). I am the
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`recipient of a 1999 Presidential Early Career Award for Scientists and Engineers
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`(PECASE) from the White House. I also received a National Science Foundation
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`Young Investigator (NYI) Award in 1994, and an Office of Naval Research Young
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`Investigator Program (YIP) Award in 1997. The Presidential White House PECASE
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`Award citation reads “For outstanding research and creative impact in multi-
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`wavelength optical techniques.”
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`19.
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`I have had extensive contributions to the international scientific
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`community in the form of internationally renowned special issue journals and
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`international conferences. I served as the primary Guest Editor for the 2018 JSTQE
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`Special Issue on “Ultra Low Loss Planar Waveguides and Their Applications,” and
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`have served as the primary Guest Editor for other special issues including the 1998
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`IEEE Journal of Lightwave Technology special issue on “Photonic Packet Switching
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`Systems” and the 2003 IEEE Journal Of Selected Areas In Communications special
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`issue on “High-Performance Optical/Electronic Switches/Routers for High-Speed
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`Internet.” I also served as one of the Guest Editors for the 2006 JSTQE Special Issue
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`on “Ultra-Fast Integrated Photonics.” In terms of regular journal editing, I was an
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`Associate Editor for the IEEE Photonics Technology Letters and an Associate Editor
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`for the IEEE Transactions on Communications for many years. I have organized and
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`served on committees for internationally renowned conferences and topical meetings
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`including as General Program Chair for the 2001 OSA Topical Meeting on Photonics
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`in Switching and as Program Chair for the 1999 Meeting on Photonics in Switching.
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`I have also served on numerous other technical program committees including the
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`Conference on Optical Fiber Communications OFC (2018 – Present and 1997 –
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`2000), the Conference on Lasers and Electrooptics CLEO (1999-2000), the European
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`Conference on Optical Communications ECOC (2004-2005) and SIGCOMM 2006.
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`20.
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`In forming the opinions expressed in this Declaration, I have relied upon
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`my education and my approximately 42 years of professional and academic
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`experience.
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`III. LEVEL OF ORDINARY SKILL IN THE ART
`21.
`I understand there are multiple factors relevant to determining the level
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`of ordinary skill in the pertinent art, including (1) the levels of education and
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`experience of persons working in the field at the time of the invention; (2) the
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`sophistication of the technology; (3) the types of problems encountered in the field;
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`and (4) the prior art solutions to those problems.
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`22. A POSITA in the field of the ’323 patent, as of its earliest possible
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`priority date of May 11, 2004, would have been someone knowledgeable and familiar
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`with communications infrastructures and the integration of ASIC devices on a fabric
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`interface. Such a POSITA would have a master’s degree in computer science,
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`computer engineering, electrical engineering, or equivalent
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`training, and
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`approximately four to six years of experience working in the field of communication
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`networks. Additional work experience can substitute for specific educational
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`background, and vice versa.
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`23. For purposes of this Declaration, in general, and unless otherwise noted,
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`my statements and opinions, such as those regarding my own experience and what a
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`POSITA would have understood or known generally (and specifically related to the
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`references I consulted herein), reflect the knowledge that existed in the relevant field
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`as of the priority date of the ’323 patent.
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`IV. RELEVANT LEGAL STANDARDS
`24.
`I am not an attorney. In preparing and expressing my opinions and
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`considering the subject matter of the ’323 patent, I am relying on certain basic legal
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`principles that Cisco’s counsel has explained to me.
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`25.
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`I understand that prior art to the ’323 patent includes patents and printed
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`publications in the relevant art that predate the priority date of the ’323 patent. For
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`purposes of this Declaration, I am applying May 11, 2004, as the priority date of the
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`’323 patent.
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`26.
`
`I have been informed by Cisco’s counsel that a claimed invention is
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`unpatentable as obvious under 35 U.S.C. § 103 if the differences between the claimed
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`invention and the prior art are such that the subject matter as a whole would have
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`been obvious at the time the invention was made to a POSITA. I have also been
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`informed by Cisco’s counsel that the obviousness analysis considers factual inquiries,
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`including the level of ordinary skill in the art, the scope and content of the prior art,
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`and the differences between the prior art and the claimed subject matter.
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`27.
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`I have been further informed by Cisco’s counsel that there are several
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`recognized rationales for combining references or modifying a reference to show
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`obviousness. These rationales include: (a) combining prior art elements according to
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`known methods to yield predictable results; (b) simple substitution of one known
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`element for another to obtain predictable results; (c) use of a known technique to
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`improve a similar device (method, or product) in the same way; (d) applying a known
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`technique to a known device (method, or product) ready for improvement to yield
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`predictable results; (e) choosing from a finite number of identified, predictable
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`solutions, with a reasonable expectation of success; and (f) some teaching,
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`suggestion, or motivation in the prior art that would have led a POSITA to modify
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`the prior art or to combine prior art teachings to arrive at the claimed invention.
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`28. Also, I have been informed and understand that obviousness does not
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`require physical combination/bodily incorporation, but rather consideration of what
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`the combined teachings would have suggested to a POSITA at the time of the alleged
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`invention.
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`V. BACKGROUND
`29. Optical communications has proved a cost-efficient way to modulate
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`and receive high-speed optical data (signals) over short to long distances since at least
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`the 1970s. The basic elements of a point-to-point optic transmission link consist of
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`an optical transmitter and optical receiver connected over an optical fiber or an optical
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`waveguide (See Fig. 3.1 Kazovsky1996 (Ex.1021)). Depending on the link length
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`Declaration of Daniel Blumenthal
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`(distance) and data capacity (number of bits per second) optical amplification may be
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`used during transmission. The optical fiber and it its compact chip-based counterpart
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`the optical waveguide, have proved to be a cost and space efficient way to move high-
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`speed data over many distances, from on a chip, to between chips on a circuit board,
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`to between circuit boards, to between data equipment racks, and beyond to national
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`and global distances.
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`
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`Fig. 3.1 Kazovsky1996 (Ex.1021)
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`30. The most basic fiber link is an intensity modulated direct detection (IM-
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`DD) binary communication optic link that consists of a transmitter, an optical fiber
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`and a receiver, as shown in Fig. 3.1 Kazovsky1996 (Ex.1021). Electronic data to be
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`transmitted either drives a semiconductor laser directly or drives an optical modulator
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`that has a continuous wave (cw) or pulsed light source (e.g., a laser or light emitting
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`diode LED) connected to its optical input. The current into the laser or the signal into
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`the optical modulator impresses the data from the information source onto the optical
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`carrier in the form of binary on-off light modulation, and the modulated optical signal
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`Declaration of Daniel Blumenthal
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`is input to an optical waveguide or an optical fiber. At the receiving end of the fiber
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`a photodetector converts the on-off modulated light to an electrically modulated
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`signal (current) that is converted to an electrically modulated voltage representative
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`of the data. This analog received voltage signal is amplified and equalized to optimize
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`the signal to noise ratio (SNR) and minimize signal distortion. The amplified-filtered
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`signal is then passed to a digital binary decision circuit that converts the received
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`analog voltage to a digital binary data stream that is input to an information sink.
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`31. The capacity of a fiber optic link can be increased by transmitting
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`multiple of these IM-DD data streams in parallel over the same fiber by transmitting
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`each channel on a different wavelength (optical frequency). Such a system is called
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`wavelength division multiplexed (WDM) or frequency division multiplexed fiber
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`optic transmission system. The single wavelength IM-DD link in Fig. 3.1
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`Kazovsky1996 can be replicated over multiple different wavelengths to build a WDM
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`link as shown in Fig. 7.15 Kazovaky1996 (Ex.1021). Each of N transmitters, each
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`operating at a different wavelength λi for i = 1-N, is connected to a wavelength
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`division multiplexer that combines the modulated wavelengths onto the same fiber.
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`A wavelength demultiplexer is used at the fiber output, and sends each wavelength
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`to a dedicated receiver for that wavelength. The transmitter and receiver design
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`considerations for this architecture are somewhat the same as a single wavelength
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`IM-DD link, except for details of added loss from the multiplexer/demultiplexer and
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`other wavelength crosstalk and nonlinearity considerations. But essentially, each
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`receiver detector is receiving only one data modulated wavelength and can be
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`optimized for the power in that channel. When the number of optical wavelengths
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`(frequencies) are increased to beyond approximately 32 in a single fiber, these
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`systems are referred to as Dense WDM or DWDM. The parallelism of fiber optics
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`can also be used to increased capacity by transmitting over parallel optical fibers,
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`called space-division multiplexing (SDM), and combinations of WDM and SDM are
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`also employed.
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`Figure 7.15 Kazovsky1996 (Ex.1021)
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`
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`32. The capacity can be further
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`increased using coherent optical
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`communications techniques and more sophisticated modulation techniques for each
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`wavelength stream. A basic single wavelength coherent optical link, is illustrated in
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`Declaration of Daniel Blumenthal
`Inter Partes Review of U.S. 7,921,323
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`Fig. 4.1 Kazovsky1996 (Ex.1021). There are well-known tradeoffs between
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`incoherent (described above) and coherent links, including cost, complexity, and
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`power consumption. For example, a coherent link can tolerate higher fiber loss and
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`can transmit at higher bit-rates over longer distances than an incoherent link.
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`
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`Figure. 4.1 Kazovsky1996 (Ex.1021)
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`33.
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`It has been well-known since the early 1980s that optical transmission
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`can provide high-speed connections on and between electronic chips. For example,
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`optical waveguide interconnections were proposed to support high-speed on-chip
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`communications delivery by Goodman in 1984 (see Figure 4, Goodman1984)
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`(Ex.1022).
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`Figure 4, Goodman1984 (Ex.1022)
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`34. Since before 2000
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`it has also been well-known
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`that optical
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`communications can be used for high-speed data delivery over a wide range of
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`applications and distances from on-chip, as in Goodman1984, to multi-chip modules
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`(MSMs) where one module contains multiple chips, chip-to-chip, board-to-board,
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`rack-to-rack and beyond. For example Michalzik2000 summarizes such applications
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`in quotes below, and is illustrated in Figure 6.1 Michalizik2000 (Ex.1023).
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`It has become customary to classify optical interconnects
`into distinct, albeit overlapping, categories. Some of those
`are illustrated in Fig. 6.1, ranging from the longest to the
`shortest transmission distance: ~ Rack-to-rack, also called
`frame-to-frame;  ~ Board-to-board; ~ Multi-chip module
`(MCM)-to-MCM or intraboard; ~ Chip-to-chip on a single
`MCM; ~ Intra- or on-chip.
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`Figure 6.1 Michalzik2000 (Ex.1023)
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`35. Examples of high-speed waveguide and fiber board-level optical
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`interconnects have been well-known since at least 1996, as described for parallel fiber
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`SDM links as shown in optic Figure 1 Hahn1996 (Ex.1024). In this type of
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`implementation, the optical transmitters and receivers are implanted at the circuit-
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`board level.
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`Figure 1. Hahn1996 (Ex.1024)
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`36. The implementation of parallel fiber SDM transmitters and receivers in
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`small form factor optical pluggable modules has been driven by the need to provide
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`reduced size, power, and cost in a field-replaceable modular form factor as described
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`by Michalzik2000 in Figure 6.3 (Ex.1023).
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`Figure 6.3 Michalzik2000 (Ex.1023)
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`37. While optical transmitters and receivers provide the necessary interface
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`between electronic data switching and
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`routing equipment and optical
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`waveguides/fiber, these interfaces consume power and space and can be costly as the
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`bandwidth and capacity scale. As the data capacity increases between electronic
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`switching and routing equipment, it may be desirable to use methods to switch or
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`route data, packets and connections using all-optical techniques instead of the power
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`and space consuming conversion that occurs between electrical and optical signals.
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`38. Areas in optical communications that focus on achieving this goal
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`include optical routing and optical packet switching. An example of an optical packet
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`switching architecture and technology is described in Blumenthal2001 and
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`interconnect processing devices that were used, as illustrated in Figure 1
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`Blumenthal2001 (Ex.1025). Packetized data that originates from electronic packet
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`switches and routers, that are transmitted on a optical fiber or waveguide, contains
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`Declaration of Daniel Blumenthal
`Inter Partes Review of U.S. 7,921,323
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`headers in front of the data that specify information about where the packet is to go,
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`where it came from, as well as other information. When entering the optical router
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`(Figure 1 Blumenthal2001 (Ex.1025)) the header is optically removed (erased)
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`without converting the signal back to electronics and a portion of the signal is
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`photodetected and received by control electronics to compute a new header, which is
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`then added back to the optical packet while it is moving through the router. The
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`“updated” packet with new header is then converted all-optically to a new wavelength
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`of light and routed to an output fiber or waveguide.
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`Figure 1. Blumethal2001 (Ex.1025)
`39. S