General Publications

S. Ashrafi, etal. “Spurious Resonances and Modelling of Composite Resonators,” 37th Annual Symposium on Frequency Control. 1983

 

S. Ashrafi, etal. “Acoustically induced stresses in elastic cylinders and their visualization,” The Journal of the Acoustical Society of America 82(4):1378-1385 · September 1987

 

S. Ashrafi, etal. “Splitting and contrary motion of coherent bremsstrahlung peaks in strained-layer superlattices,” Journal of Applied Physics 70:4190-4193 · December 1990

 

S. Ashrafi, etal. “Channeling Radiation of Electrons in Crystal Lattices, Essays on Classical and Quantum Dynamics,” Gordon and Breach Science Publishers, 1991

 

S. Ashrafi, etal. “Splitting of channeling-radiation peaks in strained-layer superlattices,” Journal of the Optical Society of America B 8(12), November 1991

 

S. Ashrafi, etal. “Evidence of Chaotic Pattern in Solar Flux through a Reproducible Sequence of Period-Doubling-Type Bifurcations,” Proceedings of Flight Mechanics/Estimation Theory Symposium, National Aeronautics and Space Administration, May 1991

 

S. Ashrafi, etal. “Lyapunov Exponent of Solar Flux Time Series,” Proceedings of First Experimental Chaos Conference, June 1991

 

S. Ashrafi, etal. “Future Mission Studies: Combining Schatten’s Solar Activity Prediction Model with a Chaotic Prediction Model,” National Aeronautics and Space Administration, November 1991

 

S. Ashrafi, etal. “Techniques for Forecasting Solar Activity Directly From its Time Series,” Proceedings of Flight Mechanics/Estimation Theory Symposium, National Aeronautics and Space Administration, May 1992

 

S. Ashrafi, etal. “Detecting and Disentangling Nonlinear Structure from Solar Flux Time Series,” 43rd Congress of the International Astronautical Federation, August 1992

 

S. Ashrafi, etal. “Study of Solar Cycles Using Turbulent Dynamo,” NASA STI/Recon Technical Report, 1992

 

S. Ashrafi, etal. “Solar Flux Forecasting Using Mutual Information with an Optimal Delay,” Advances in the Astronautical Sciences, American Astronautical Society, Vol. 84 Part II, 1993

 

S. Ashrafi, etal. “PCS system design issues in the presence of microwave OFS, Electromagnetic Wave Interactions, Series on Stability,” Vibration and Control of Systems, World Scientific, January 1996

 

S. Ashrafi, etal. “Performance Metrics and Design Parameters for an FSO Communications Link Based on Multiplexing of Multiple Orbital-Angular-Momentum Beams,” Globecom2014 OWC Workshop, 2014

 

S. Ashrafi, etal. “Optical Communications Using Orbital Angular Momentum Beams,” Adv. Opt. Photon. 7, 66-106, Advances in Optics and Photonic, 2015

 

S. Ashrafi, etal. “Performance Enhancement of an Orbital-Angular-Momentum-Based Free-Space Optical Communication Link through Beam Divergence Controlling,” OSA Technical Digest, paper M2F.6. The Optical Society, 2015

 

S. Ashrafi, etal. “Experimental demonstration of enhanced spectral efficiency of 1.18 symbols/s/Hz using multiple-layer-overlay modulation for QPSK over a 14-km fiber link,” OSA Technical Digest, paper JTh2A.63. The Optical Society, 2014

 

S. Ashrafi, etal. “Link Analysis of Using Hermite-Gaussian Modes for Transmitting Multiple Channels in a Free-Space Optical Communication System,” The Optical Society, Vol. 2, No. 4, April 2015

 

S. Ashrafi, etal. “Performance Metrics and Design Considerations for a Free-Space Optical Orbital-Angular-Momentum-Multiplexed Communication Link,” The Optical Society, Vol. 2, No. 4, April 2015

 

S. Ashrafi, etal. “Demonstration of Distance Emulation for an Orbital-Angular-Momentum Beam,” OSA Technical Digest, paper STh1F.6. The Optical Society, 2015

 

S. Ashrafi, etal. “Free-Space Optical Communications Using Orbital-Angular-Momentum Multiplexing Combined with MIMO-Based Spatial Multiplexing,” Optics Letters, Vol. 40, No.18, September 4, 2015

 

S. Ashrafi, etal. “Enhanced Spectral Efficiency of 2.36 bits/s/Hz Using Multiple Layer Overlay Modulation for QPSK over a 14-km Single Mode Fiber Link,” OSA Technical Digest, paper SW1M.6. The Optical Society, 2015

 

S. Ashrafi, etal. “Experimental Demonstration of a 400-Gbit/s Free Space Optical Link Using Multiple Orbital-Angular-Momentum Beams with Higher Order Radial Indices,” OSA Technical Digest, paper SW4M.5. The Optical Society, 2015

 

S. Ashrafi, etal. “Experimental Demonstration of 16-Gbit/s Millimeter-Wave Communications Link using Thin Metamaterial Plates to Generate Data-Carrying Orbital-Angular-Momentum Beams,” ICC 2015, London, UK, 2014

 

S. Ashrafi, etal. “Experimental Demonstration of Using Multi-Layer-Overlay Technique for Increasing Spectral Efficiency to 1.18 bits/s/Hz in a 3 Gbit/s Signal over 4-km Multimode Fiber,” OSA Technical Digest, paper JTh2A.63. The Optical Society, 2015

 

S. Ashrafi, etal. “Experimental Measurements of Multipath-Induced Intra- and Inter-Channel Crosstalk Effects in a Millimeter-Wave Communications Link using Orbital-Angular-Momentum Multiplexing,” ICC 2015, London, UK, 2014

 

S. Ashrafi, etal. “400-Gbit/s Free-Space Optical Communications Link Over 120-meter Using Multiplexing of 4 Collocated Orbital-Angular-Momentum Beams,” OSA Technical Digest, paper M2F.1. The Optical Society, 2015

 

S. Ashrafi, etal. “Experimental Demonstration of Two-Mode 16-Gbit/s Free-Space mm-Wave Communications Link Using Thin Metamaterial Plates to Generate Orbital Angular Momentum Beams,” Optica, Vol. 1, No. 6, December 2014

 

S. Ashrafi, etal. “Demonstration of an Obstruction-Tolerant Millimeter-Wave Free-Space Communications Link of Two 1-Gbaud 16-QAM Channels using Bessel Beams Containing Orbital Angular Momentum,” Third International Conference on Optical Angular Momentum (ICOAM), 4 - 7 August 2015, New York USA 

 

S. Ashrafi, etal. “Patch Antenna Array for the Generation of Millimeter-wave Hermite-Gaussian Beams,” IEEE Antennas and Wireless Propagation Letters, Volume 15, 2016

 

S. Ashrafi, etal. “Physical Phase plate for the Generation of a Millimeter-Wave Hermite-Gaussian Beam,” IEEE Antennas and Wireless Propagation Letters, LAWP 2016 1947-1950

 

S. Ashrafi, etal. “Orbital and Angular Momentum Multiplexed Free Space Optical Communication Link Using Transmitter Lenses,” Applied Optics, 10 March 2016, Vol. 55, No. 8

 

S. Ashrafi, etal. “Experimental Characterization of a 400 GBit/s Orbital Angular Momentum Multiplexed Free Space Optical Link Over 120 m,” Optics Letters, 1 February 2016

 

S. Ashrafi, etal. “Tunable Generation and Angular Steering of a Millimeter-Wave Orbital-Angular-Momentum Beam using Differential Time Delays in a Circular Antenna Array,” IEEE ICC 2016 - Wireless Communications Symposium

 

S. Ashrafi, etal. “A Dual-Channel 60GHz Communications Link Using Patch Antenna Arrays to Generate Data Carrying OAM Beams,” IEEE ICC 2016 – Wireless Communications Symposium

 

S. Ashrafi, etal. “Demonstration of OAM-based MIMO FSO link using spatial diversity and MIMO equalization for turbulence mitigation,” Optical Fiber Conf. 2016: OSA 2016,
IEEE Aug. 11, 2016

 

S. Ashrafi, etal. “Dividing and Multiplying the Mode Order for OAM Beams,” Ecoc 2015 – ID: 0716

 

S. Ashrafi, etal. “Exploiting the Unique Intensity Gradient of an OAM Beam for Accurate Receiver Alignment Monitoring in Free-Space Communication Link,” Ecoc 2015 – ID: 066

 

S. Ashrafi, etal. “CMA Equalization for a 2 Gb/s OAM Multiplexed Optical Underwater Link through Thermally Induced Refractive Index Inhomogeneity,” CLEO:2016, OSA 2016

 

S. Ashrafi, etal. “4 Gbit/s Underwater Optical Transmission Using OAM Multiplexing and Directly Modulated Green Laser,” OSA 2016

 

S. Ashrafi, etal. “Demonstration of Using Passive Integrated Phase Masks to Generate OAM Beams in a Communications Link,” CIEO: 2016, OSA 2016

 

S. Ashrafi, etal. “Future Missions Studies - Combining Schatten’s Solar Activity,” NASA, Goddard Space Flight Center, November 1991

 

S. Ashrafi, etal. “Vortex Beams and Optical Activity of Sucrose,” March 2017, Complex Light & Optical Forces XI, Proc. of SPIE Vol. 10120

 

S. Ashrafi, etal. “Multipath Effects in Millimeter Wave Wireless Communication using Orbital Angular Momentum Multiplexing,” Scientific Reports, 6:33482-DOI:10.1038/srep33482, September 2016

 

S. Ashrafi, etal. “Experimental demonstration of 16 Gbit/s millimeter-wave communications using MIMO processing of 2 OAM Modes of Each of 2 Transmitter/Receiver Antenna Apertures,” Globecom 2014 - Wireless Communications Symposium

 

S. Ashrafi, etal. “Demonstration of Tunable Steering and Multiplexing of Two 28 GHz Data Carrying Orbital Angular Momentum Beams Using Antenna Array,” Scientific Reports, 6:37078-DOI: 10.1038-srep37078 November 11, 2016

 

S. Ashrafi, etal. “Power Loss Mitigation of Orbital Angular Momentum-Multiplexed Free-Space Optical Links using Nonzero Radial Index Laguerre-Gaussian Beams,” Journal of the Optical Society of America, Vol. 34, No. 1, January 2017

 

S. Ashrafi, etal. “Division and multiplication of the state order for data-carrying orbital angular momentum beams,” APL Photonics 1, 090802, December 2016

 

S. Ashrafi, etal. “Orbital angular momentum multiplexed free space optical communication link using transmitter lenses,” Applied Optics, March 2016, Vol. 55, No. 8
 

S. Ashrafi, etal. “Orbital angular momentum based reconfigurable optical switching and routing,” October 2016, Vol. 4, No. 5, October 2016

 

S. Ashrafi, etal. “Design challenges and guidelines for free-space optical communication links using OAM multiplexing of multiple beams,” Journal of Optics, IOP Publishing, J. Opt. 18, June 14, 2016

 

S. Ashrafi, etal. “Localization from the unique intensity gradient of an orbital-angular momentum beam,” Optics Letters, Vol. 42, No. 3, February 2, 2017

 

S. Ashrafi, etal. “Hybrid Generation and Analysis of Complex Vector OAM beams,” Applied Optics, March 2017

 

S. Ashrafi, etal. “Complex Light - review the fundamental physics and the burgeoning applications of complex light beams,” Bristol UK: IOP Publishing-Book 2017

 

S. Ashrafi, etal. “Spatial light structuring using a combination of multiple orthogonal angular momentum beams with complex coefficients,” Optics Letters, Volume 42, No. 5, March 2017

 

S. Ashrafi, etal. “Theoretical Justification of Modified Maxwell’s Equations for Applications in Impulse Radar,” First Los Alamos Symposium on Ultra-Wideband Radar March 1990

 

S. Ashrafi, etal. “Recent advances in high-capacity free-space optical and radio-frequency communications using orbital angular momentum multiplexing,” Royal Society Publishing, Phil. Trans. R. Soc. A375:20150439, October 13, 2016
 

S. Ashrafi, etal. “32 Gbps/60 GHz millimeter wave wireless communication using orbital angular momentum and polarization multiplexing,” IEEE, ICC 2016 Wireless Symposium
 

S. Ashrafi, etal. “Free space optical communications link using orbital angular momentum multiplexing combined with MIMO-based spatial multiplexing,” Optic Letters, Vol. 40, Vo. 18 September 4, 2015
 

S. Ashrafi, etal. “Physical phase plate for the generation of a millimeter-wave Hermite-Gaussian Beam,” IEEE 2016

 

S. Ashrafi, etal. “Atmospheric turbulence mitigation in an OAM-based MIMO free-space optical link using spatial diversity combined with MIMO equalization,” Optic Letters, Vol 41, No. 11/ June 1, 2016

 

S. Ashrafi, etal. “Design fabrication, and demonstration of a dielectric vortex waveguide in the sub-terahertz region,” Applied Optics, Vol. 56, No. 25 / September 1, 2017

 

S. Ashrafi, etal. “Experimental demonstration of a 200-Gbit/s free-space optical link by multiplexing Laguerre-Gaussian beams with different radial indices,” Optics Letters, Vol. 41, No. 15 / August 1, 2016

 

S. Ashrafi, etal. “Future mission studies: Forecasting solar flux directly from its chaotic time series,” Flight Dynamics Division-Code 550, December 1991

 

S. Ashrafi, etal. “Future Mission Studies: Preliminary Comparisons of Solar Flux Models,” NASA, December 1991

 

S. Ashrafi, etal. “Hybrid generation and analysis of vector vortex beams,” Applied Optics, Vol. 56, No. 8 / March 10, 2017

 

S. Ashrafi, etal. “Mode division multiplexing of multiple Bessel-Gaussian beams carrying orbital angular momentum for obstruction tolerant free-space optical and millimeter wave communication links,” Scientific Reports, Published March 1, 2016

 

S. Ashrafi, etal. “Nonlinear techniques for forecasting solar activity directly from its time series,” NASA, Flight Mechanics/Estimation Theory Symposium Goddard Space Flight Center, Maryland, May 5-7, 1992

 

S. Ashrafi, etal. “Orbital angular momentum-based space division multiplexing for high capacity underwater optical communications,” Scientific Reports, Published September 12, 2016

 

S. Ashrafi, etal. “Orbital angular momentum beam generated beams passive dielectric phase masks and their performance in a communication link,” Optics Letters, Vol. 42, No. 14 / July 15, 2017

 

S. Ashrafi, etal. “Orbital angular momentum multiplexing using low-cost VCSELs for Datacenter Application,” Frontiers in Optics, Laser Science, 2016 OSA 2016

 

 

S. Ashrafi, etal. “A dual channel 60 GHz communications link using patch antenna arrays to generate data carrying orbital angular momentum beams,” IEEE ICC 2016 - Wireless Communications Symposium
 

S. Ashrafi, etal. “Spatial Phase and Amplitude Structuring of Beams Using a Combination of Multiple Orthogonal Spatial Functions with Complex Coefficients,” Physics/Optics, submitted May 28, 2016
 

S. Ashrafi, “Studies of channeling radiation and coherent bremsstrahlung. Thesis - The Catholic University of America, 1989, Published date 1989
 

S. Ashrafi, etal. “Performance metrics for a free-space communication link based on multiplexing of multiple orbital angular momentum beams with higher order radial indices,” CLEO:2015, OSA 2015
 

S. Ashrafi, etal. “Stability of Ince-Gaussian beams in elliptical core few-mode fiber,” 

Optical Letters- Manuscript ID: 324722, May 29, 2018

 

S. Ashrafi, etal. “High Capacity Point-to-Point Wireless Communications,” IEEE GLOBECOM WS-06, 2019

 

S. Ashrafi, L. Campbell “Multi-Photon, Multi-Dimensional Hyper-Entanglement using Higher-Order Radix qudits with Applications to Quantum Computing, QKD and Quantum Teleportation,”

, physics.optics, May 2020

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