Optical: systems and elements – Optical modulator – Light wave temporal modulation
Reexamination Certificate
1999-10-25
2001-04-10
Epps, Georgia (Department: 2873)
Optical: systems and elements
Optical modulator
Light wave temporal modulation
C359S247000, C359S248000
Reexamination Certificate
active
06215577
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to integrated circuits and, more specifically, the present invention relates to the modulation of light using integrated circuits.
2. Background Information
Within the integrated circuit industry there is a continuing effort to increase integrated circuit speed as well as device density. One challenge that integrated circuit designers face with increasing circuit speeds and device densities is the increasingly significant propagation delays of circuit inputs and outputs due to the capacitive loading associated with off chip circuit connections. At slower clock speeds, the capacitive loading on integrated circuit lines is generally not a significant factor. However, as newer integrated circuit design clock speeds continue to climb towards the gigahertz range and beyond, it is evident that one of the major bottlenecks for future integrated circuits, such as for example but not limited to microprocessors, off chip caches, controllers, etc., will be the input/output bandwidth and/or round trip delay between and within chips.
Prior art attempts to address the capacitive loading problems associated with increased integrated circuit speeds and device densities have resulted in the use of larger and more powerful integrated circuit input/output drivers on the chip. Undesirable consequences of utilizing larger input/output drivers include the facts that the larger input/output drivers generally consume more power, create large di/dt noise, which requires low inductance packaging and large amount of on-die decoupling capacitance to provide a means of noise suppression, dissipate more heat and occupy more of valuable area on the integrated circuit die than smaller integrated circuit input/output drivers.
Other prior art attempts to overcome traditional integrated circuit interconnection limitations have included the use of optical interconnections. The prior art attempts at optical interconnections between integrated circuits have generally involved or have been based on two typical approaches.
One approach has been based on either using gallium arsenide (GaAs) laser diodes and modulating or switching the diodes electrically or by using GaAs built modulators that amplitude modulate a laser beam passing through the integrated circuit. The modulation is generally based on electroabsorption through strained multi-layer grown molecular beam epitaxy (MBE) films in GaAs integrated circuits. As can be appreciated to those skilled in the art, it is difficult and therefore impractical to integrate or combine III-V based technology, which includes GaAs, with standard silicon based complementary metal oxide semiconductor (CMOS) technology.
The second typical prior art approach is based on using silicon based optical waveguides. These waveguides are generally built using Silicon-on-Insulator (SOI) based processing techniques. Prior art SOI based modulators utilize silicon waveguide structures to switch light passing through the optical waveguide. The switching mechanism however utilizes injection of carriers into the waveguide rather like in a bipolar based transistor. One consequence of this is slow speed, for example up to several hundred megahertz, and very high power consumption, for example 10 mW or more for a single switch. In order to increase the modulation depth, one often tries to obtain a large interaction volume between the injected charge and the optical beam. This is generally accomplished by making very long waveguides, for example on order of thousands of microns, thereby increasing the interaction length through which the optical beam travels. As can be appreciated to those skilled in the art, actual incorporation of SOI waveguides into existing multi-layer standard CMOS based processing however is not straight forward. Hence, utilization of these waveguide structures becomes quite impractical when used for high speed input/output in large transistor count microprocessors.
SUMMARY OF THE INVENTION
A method and an apparatus of an optical modulator are disclosed. In one embodiment, an optical modulator includes a charged region disposed in a semiconductor substrate of an integrated circuit die. A first deflector is disposed proximate to the charged region. The first deflector is to deflect an optical beam directed through the charged region back through the charged region. A second deflector is disposed opposite the first deflector. The second deflector to deflect the optical beam deflected away from the first deflector back through the charged region to the first deflector. The optical beam is to be directed away from the optical modulator after a plurality of deflections of the optical beam through the charged region between the first and second deflectors. Additional features and benefits of the present invention will become apparent from the detailed description, figures and claims set forth below.
REFERENCES:
patent: 3158746 (1964-11-01), Lehovec
patent: 3242805 (1966-03-01), Harrick
patent: 4422088 (1983-12-01), Gfeller
patent: 4695120 (1987-09-01), Holder
patent: 4758092 (1988-07-01), Heinrich et al.
patent: 4761620 (1988-08-01), Bar-Joseph et al.
patent: 4848880 (1989-07-01), Aull et al.
patent: 4865427 (1989-09-01), Kingston et al.
patent: 4871224 (1989-10-01), Karstensen et al.
patent: 4917450 (1990-04-01), Pocholle et al.
patent: 4966430 (1990-10-01), Weidel
patent: 5061027 (1991-10-01), Richard
patent: 5153770 (1992-10-01), Harris
patent: 5159700 (1992-10-01), Reid
patent: 5198684 (1993-03-01), Sudo
patent: 5400419 (1995-03-01), Heinen
patent: 5432630 (1995-07-01), Lebby et al.
patent: 5434434 (1995-07-01), Kasahara et al.
patent: 5485021 (1996-01-01), Abe
patent: 5502779 (1996-03-01), Magel
patent: 5568574 (1996-10-01), Tanguay, Jr. et al.
patent: 5605856 (1997-02-01), Goosen et al.
patent: 5625636 (1997-04-01), Bryan et al.
patent: 5629838 (1997-05-01), Knight
patent: 5638469 (1997-06-01), Feldman et al.
patent: 5696862 (1997-12-01), Hauer et al.
patent: 5835646 (1998-11-01), Yoshimura et al.
patent: 5864642 (1999-01-01), Chun et al.
patent: 5872360 (1999-02-01), Paniccia et al.
patent: 5963358 (1999-10-01), Shields
patent: 5966234 (1999-10-01), Ford et al.
patent: 6072179 (2000-06-01), Paniccia et al.
patent: 6075908 (2000-06-01), Paniccia et al.
Miller, DAB: “Reason and Prospects for Dense Optical Interconnections”, Presentation by Stanford University Professor, (Oct. 1997).
Sakano, S. et al.: “InGaAsP/InP Monolithic Integrated Circuit with Lasers and an Optical Switch,” Electronics Letters, 22(11), May 1986.
Mansuripur, M. and Goodman, JW: “Signal and Noise in Magneto-Optical Readout,” J. Appl. Phys., 53(6), Jun. 1982.
“Optoelectronic VLSI Foundry Services From Lucent Technologies”, Lucent Technologies Bell Labs Innovations Web Page at http://www.bell-labs.com/project/oevlsi/, updated Mar. 2, 1997.
“Process for Fabricating OE/VLSI Chips”, Lucent Technologies Bell Labs Innovations Web Page at http://www.bell-labs.com/project/oeflsi/wfabproc.html, updated Sep. 26, 1996.
“Detailed Design Rules for Workshop Chips”, Lucent Technologies Bell Labs Innovations Web Page at http://www.bell-labs.com/roject/oevlsi/wdesrule.html, updated Mar. 7, 1997.
Cutolo, A., et al.: Sillicon Electro-Optic Modulator Based on a Three Terminal Device Integrated in a Low-Loss Single-Mode SOI Waveguide in J. of Lightwave Technology, vol.15(3), Mar. 1997.
Raybon, G., et al.: “A Reconfigurable Optoelectronic Wavelength Converter based on an Integrated Electroabsorption Modulated Laser Array” in 1997 Digest of the IEEE/LEOS Summer Topical Meetings, Montreal, Quebec, Canada, Aug. 1997.
Reiley, DJ, and Sasian JM: “Optical Design of a Free-Space Photonic Switching System” in Applied Optics, vol. 36(19), Jul. 1997.
Heinrich, HK: “A Noninvasive Optical Probe for Detecting Electrical Signals in Silicon Integrated Circuits”, Doctoral Dissertation, Stanford Univ., (Apr., 1987).
Orobtchouk, R., et al.: “Quasi-TEoo Singlemode Optical Waveguides for Electro-optical Modulation at 1.3&mgr;m Using Standard SIMOX Materi
Koehl Sean M.
Nikonov Dmitri
Paniccia Mario J.
Blakely , Sokoloff, Taylor & Zafman LLP
Epps Georgia
Intel Corporation
O'Neill Gary
LandOfFree
Method and apparatus for optically modulating an optical... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for optically modulating an optical..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for optically modulating an optical... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2493455