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Power-efficient dual-rate optical transceiver

Yongrong Zuo, Fouad E. Kiamiley, Xiaoqing Wang, Ping Gui, Jeremy Ekman, Xingle Wang, Michael J. McFadden, Michael W. Haney
2005 Applied Optics  
A dual-rate ͑2 Gbit͞s and 100 Mbit͞s͒ optical transceiver designed for power-efficient connections within and between modern high-speed digital systems is described. The transceiver can dynamically adjust its data rate according to performance requirements, allowing for power-on-demand operation. Dynamic power management permits energy saving and lowers device operating temperatures, improving the reliability and lifetime of optoelectronic-devices such as vertical-cavity surface-emitting lasers
more » ... (VCSELs). To implement dual-rate functionality, we include in the transmitter and receiver circuits separate high-speed and low-power data path modules. The high-speed module is designed for gigabit operation to achieve high bandwidth. A simpler low-power module is designed for megabit data transmission with low power consumption. The transceiver is fabricated in a 0.5 m silicon-on-sapphire complementary metal-oxide semiconductor. The VCSEL and photodetector devices are attached to the transceiver's integrated circuit by flip-chip bonding. A free-space optical link system is constructed to demonstrate correct dual-rate functionality. Experimental results show reliable link operation at 2 Gbit͞s and 100 Mbit͞s data transfer rates with ϳ104 and ϳ9 mW power consumption, respectively. The transceiver's switching time between these two data rates is demonstrated as 10 s, which is limited by on-chip register reconfiguration time. Improvement of this switching time can be obtained by use of dedicated input-output pads for dual-rate control signals.
doi:10.1364/ao.44.007112 pmid:16318182 fatcat:i3mmweyn4rhqjjyyhg7jq2th5y

Performance-based adaptive power optimization for digital optical interconnects

Xiaoqing Wang, Fouad Kiamilev, George C. Papen, Jeremy Ekman, Ping Gui, Michael J. McFadden, Joseph C. Deroba, Michael W. Haney, Charles Kuznia
2005 Applied Optics  
Optical links are traditionally set to transmit maximum power for worst-case loss and consequently to dissipate more power than is required. We describe a technique to minimize power consumption based on the measured bit-error rate (BER) of the link. This technique uses a novel power-negotiation algorithm that optimizes the link power setting to achieve minimum power dissipation for a target BER. A 0.5 m complementary metal-oxide semiconductor optical transceiver chip was fabricated, and a
more » ... pace optical interconnect system was built for validation. The results showed that the algorithm was able to find the optimum power settings for the VCSELs for a target BER and to account for dynamic changes such as variation in the optical loss in the system.
doi:10.1364/ao.44.006240 pmid:16237941 fatcat:pzzxbvmjwrb6bk6jshsfbyy2n4

Multichip free-space global optical interconnection demonstration with integrated arrays of vertical-cavity surface-emitting lasers and photodetectors

Michael W. Haney, Marc P. Christensen, Predrag Milojkovic, Jeremy Ekman, Premanand Chandramani, Richard Rozier, Fouad Kiamilev, Yue Liu, Mary Hibbs-Brenner
1999 Applied Optics  
The experimental optical interconnection module of the Free-Space Accelerator for Switching Terabit Networks ͑FAST-Net͒ project is described and characterized. Four two-dimensional ͑2-D͒ arrays of monolithically integrated vertical-cavity surface-emitting lasers ͑VCSEL's͒ and photodetectors ͑PD's͒ were designed, fabricated, and incorporated into a folded optical system that links a 10 cm ϫ 10 cm multichip smart pixel plane to itself in a global point-to-point pattern. The optical system effects
more » ... a fully connected network in which each chip is connected to all others with a multichannel bidirectional data path. VCSEL's and detectors are arranged in clusters on the chips with an interelement spacing of 140 m. Calculations based on measurements of resolution and registration tolerances showed that the square 50-m detector in a typical interchip link captures approximately 85% of incident light from its associated VCSEL. The measured optical transmission efficiency was 38%, with the losses primarily due to reflections at the surfaces of the multielement lenses, which were not antireflection coated for the VCSEL wavelength. The overall efficiency for this demonstration is therefore 32%. With the measured optical confinement, an optical system that is optimized for transmission at the VCSEL wavelength will achieve an overall efficiency of greater than 80%. These results suggest that, as high-density VCSELbased smart pixel technology matures, the FAST-Net optical interconnection concept will provide a low-loss, compact, global interconnection approach for high bisection-bandwidth multiprocessor applications in switching, signal processing, and image processing.
doi:10.1364/ao.38.006190 pmid:18324143 fatcat:wsxvukzndfhvholscni4c2dnea

FAST-Net optical interconnection prototype demonstration

Michael W. Haney, Marc P. Christensen, Predrag Milojkovic, Jeremy T. Ekman, Premanand Chandramani, Richard G. Rozier, Fouad E. Kiamilev, Yue Liu, Mary K. Hibbs-Brenner, Jim Nohava, Edith Kalweit, Sommy Bounnak (+5 others)
1998 Optics in Computing '98  
The first prototype of the free-space accelerator for switching terabit networks (FAST-Net) program is described. The optical interconnection module consists of an array of matched high-resolution, wide-angle ( f /1.1) imaging lenses that effect a global point-to-point shuffle link pattern across a multichip smart pixel array. A mirror is used to fold the shuffled links back onto the array to facilitate single-plane multichip packaging and simplified opto-mechanical alignment. The test system
more » ... corporates several monolithically integrated two-dimensional arrays of vertical-cavity surface-emitting lasers (VCSELs) and photodetectors (PDs) in the multichip plane. In initial experiments the prototype showed good overall optical efficiency and sufficient channel separation for VCSEL/PD arrays with pitches as small as 100 µm. These results suggest that high bisection bandwidth optical free-space interconnection fabrics are feasible for high-throughput switching and multiprocessor applications.
doi:10.1117/12.308879 fatcat:35ed6lghf5a6dahhnof4fo2a24

Page 219 of Missouri Botanical Garden. Annals of the Missouri Botanical Garden Vol. 25, Issue 1 [page]

1938 Missouri Botanical Garden. Annals of the Missouri Botanical Garden  
mountain several miles west of town, April 17, 1929, Leonard ¢ Leonard 14769 (US); trail to Moustique Mts., vicinity of Bassin Bleu, April 21, 1929, Leonard § Leonard 14930 (US); Massif de la Hotte, Jeremie  ...  8, 1927, Ekman 8084 (US); Massif de la Hotte, prope Petit-Goave, Aug. 1, 1926, Ekman 6565 (B); Port-au-Prince, in horto eult., Oct. 6, 1924, Ekman 2053 (B) ; inter Massif de la Selle et La Hotte prope  ... 

Page 219 of Missouri Botanical Garden. Annals of the Missouri Botanical Garden Vol. 25, Issue 1 [page]

1938 Missouri Botanical Garden. Annals of the Missouri Botanical Garden  
mountain several miles west of town, April 17, 1929, Leonard ¢ Leonard 14769 (US); trail to Moustique Mts., vicinity of Bassin Bleu, April 21, 1929, Leonard §& Leonard 14930 (US); Massif de la Hotte, Jeremie  ...  8, 1927, Ekman 8084 (US); Massif de la Hotte, prope Petit-Goave, Aug. 1, 1926, Ekman 6565 (B); Port-au-Prince, in horto eult., Oct. 6, 1924, Ekman 2053 (B) ; inter Massif de la Selle et La Hotte prope  ... 

Page 39 of The American Midland Naturalist Vol. 60, Issue 3 [page]

1958 The American Midland Naturalist  
Near Constant, east of Aux Cayes, Massif de la Hotte, on rocks, ca. 1100 m, Ekman 783, Sept. 5, 1917.  ...  Vicinity of large springs at source of Riviére Tissier, Grand’Anse valley near Mare Franc, 6 km SW. of Jérémie, Bartlett 17572, May 6, 1941.  ... 

Surface estimates of the Atlantic overturning in density space in an eddy-permitting ocean model

Jeremy P. Grist, Simon A. Josey, Robert Marsh
2012 Journal of Geophysical Research  
The inclusion of the anomalous Ekman Transport increases the amount of variance explained by an average 16 % throughout the North Atlantic and provides the greatest potential for estimating the variability  ...  The inclusion of the anomalous Ekman Transport increases the amount of variance explained by an average 16 % throughout the North Atlantic and provides the greatest potential for estimating the variability  ... 
doi:10.1029/2011jc007752 fatcat:pswfrslnsjbthnyw7gj2q2txta

Page 640 of Missouri Botanical Garden. Annals of the Missouri Botanical Garden Vol. 20, Issue 4 [page]

1933 Missouri Botanical Garden. Annals of the Missouri Botanical Garden  
May 20, 1927, Ekman 8173 (B, 8, US); prope Terre-Neuve, Sept. 3, 1899, Buch 88 (B); ad Jerémie, Jan. 18, 1888, Eggers 3389 (B); Camp-Perrin, alt. 200 m., Aug. 29 1888, Christ 1904 (B); Port au Prince,  ...  , 1905, Nash & Taylor 1809 (NY); common in dry thickets of La Vallée valley, Tortue Island, Jan. 6, 1929, Leonard & Leonard 11735 (NY, US); Ie La Navasse, east of the lighthouse, rare, Oct. 21, 1928, Ekman  ... 

Page 640 of Missouri Botanical Garden. Annals of the Missouri Botanical Garden Vol. 20, Issue 4 [page]

1933 Missouri Botanical Garden. Annals of the Missouri Botanical Garden  
May 20, 1927, Ekman 8173 (B, 8, US); prope Terre-Neuve, Sept. 3, 1899, Buch 89 (B); ad Jerémie, Jan. 18, 1888, Eggers 3389 (B); Camp-Perrin, alt. 200 m., Aug. 29, 1888, Christ 1904 (B); Port au Prince,  ...  1905, Nash & Taylor 1309 (NY); common in dry thickets of La Vallée valley, Tortue Island, Jan. 6, 1929, Leonard & Leonard 11735 (NY, US); Ile La Navasse, east of the lighthouse, rare, Oct. 21, 1928, Ekman  ... 

Subcritical convection in rapidly rotating liquid metal spheres [article]

Nathanael Schaeffer, Elliot Kaplan, Philippe Cardin, Céline Guervilly, Jérémie Vidal
2017 Figshare  
Planetary​ ​cores​ ​consist​ ​of​ ​liquid​ ​metals​ ​(low​ ​Prandtl​ ​number​ ​Pr)​ ​that​ ​convect​ ​as​ ​the​ ​core​ ​cools.Here​ ​we​ ​study​ ​nonlinear​ ​convection​ ​in​ ​a​ ​rotating​ ​(low​ ​Ekman​  ...  number E = ν/L 2 Ω ≤ 10 −5 but also a small thermal Ekman number E /Pr ≤ 10 −4 .  ...  thermal diffusivity κ, rotating at Ω and driven by cooling from outside: The Rayleigh number Ra measures this cooling rate; For a liquid metal we need Pr = ν/κ 1; Rapid rotation translates into a small Ekman  ... 
doi:10.6084/m9.figshare.5619370.v1 fatcat:sqf2cx36unhv7odhdsrts7c3sy

Page 325 of Missouri Botanical Garden. Annals of the Missouri Botanical Garden Vol. 44, Issue 4 [page]

1957 Missouri Botanical Garden. Annals of the Missouri Botanical Garden  
WITHOUT PRECISE LOCALITY: Moca, Ekman NH 11270 (US); Haina, Faris 38 (US, NY); Llanos de Rafael, Eggers 1920 (NY, US); Constanza, von Tiirckheim 2529 (NY).  ...  NORD-OUEST: Jean-Rabel, Leonard & Leonard 12925 (US); Port-de-Paix, Leonard & Leonard 11001 (GH, US); vicinity of Bombardopolis, Leonard & Leonard 13448 (NY, US). sup: west of Jérémie, Holdridge 928 (US  ... 

Page 325 of Missouri Botanical Garden. Annals of the Missouri Botanical Garden Vol. 44, Issue 4 [page]

1957 Missouri Botanical Garden. Annals of the Missouri Botanical Garden  
WITHOUT PRECISE LOCALITY: Plaine Centrale, Pavane-Papaye, Ekman H6013 (US); La Cumbre, Raunkaier 1137 (US).  ...  NORD-OvVEsT: Jean-Rabel, Leonard & Leonard 12925 (US); Port-de-Paix, Leonard & Leonard 11001 (GH, US); vicinity of Bombardopolis, Leonard & Leonard 13448 (NY, US). sup: west of Jérémie, Holdridge 928 (  ... 

Traveling waves in a magnetized Taylor-Couette flow

Wei Liu, Jeremy Goodman, Hantao Ji
2007 Physical Review E  
The waves appear to be absorbed near the Ekman jet, at z ≈ 100 mm.  ...  After the switch, the Ekman circulation stops and the traveling waves disappear after one axial propagation time, as if they had been emitted by the Ekman layer at the upper endcap or by the layers on  ... 
doi:10.1103/physreve.76.016310 pmid:17677566 fatcat:utrjdv4mwnemvh4yb7wtgo42ce

Page 1316 of The Journal of Animal Ecology Vol. 77, Issue 6 [page]

2008 The Journal of Animal Ecology  
Edgerly-Rooks Francois Edwards Peter Eklov Jan Ekman J. Malcolm Elliott Alicia Ellis David A. Elston Katja Enberg Steinar Engen 2008 British Ecological Society  ...  Clark Aaron Clauset Marcus Clauss Andrew Cockburn Edward Codling Nick Colegrave Jeremy S. Collie Tilly Collins Isabelle Colson David W. Coltman Bradley Charles Congdon Paul B. Conn Sean D.  ... 
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