The present invention relates to concentration measurements of various organic and non-organic materials, and more particularly, to concentration measurements of organic and non-organic materials using the orbital angular momentum of waves passed through a sample of the material.
Concentration measurements of organic and non-organic materials within human tissue is an increasingly important aspect of healthcare for individuals. The development of non-invasive measurement techniques for monitoring biological and metabolic agents within human tissue is an important aspect of diagnosis therapy of various human diseases and may play a key role in the proper management of diseases.
One example of a biological agent that may be monitored for within human tissue is glucose. Glucose (C6H12O6) is a monosaccharide sugar and is one of the most important carbohydrate nutrient sources. Glucose is fundamental to almost all biological processes and is required for the production of ATP adenosine triphosphate and other essential cellular components. The normal range of glucose concentration within human blood is 70-160 mg/dl depending on the time of the last meal, the extent of physical tolerance and other factors. Freely circulating glucose molecules stimulate the release of insulin from the pancreas. Insulin helps glucose molecules to penetrate the cell wall by binding two specific receptors within cell membranes which are normally impermeable to glucose.
One disease associated with issues related to glucose concentrations is diabetes. Diabetes is a disorder caused by the decreased production of insulin, or by a decreased ability to utilize insulin and transport the glucose across cell membranes. As a result, a high potentially dangerous concentration of glucose can accumulate within the blood (hyperglycemia) during the disease. Therefore, it is of great importance to maintain blood glucose concentration within a normal range in order to prevent possible severe physiological complications.
One significant role of physiological glucose monitoring is the diagnosis and management of several metabolic diseases, such as diabetes mellitus (or simply diabetes). There are a number of invasive and non-invasive techniques presently used for glucose monitoring. The problem with existing non-invasive glucose monitoring techniques is that a clinically acceptable process has not yet been determined. Standard techniques from the analysis of blood currently involve an individual puncturing a finger and subsequent analysis of collected blood samples from the finger. In recent decades, non-invasive blood glucose monitoring has become an increasingly important topic of investigation in the realm of biomedical engineering. In particular, the introduction of optical approaches have caused some advances within the field. Advances in optics have led to a focused interest in optical imaging technologies and the development of non-invasive imaging systems. The application of optical methods to monitoring in cancer diagnostics and treatment is also a growing field due to the simplicity and low risk of optical detection methods.
Many optical techniques for sensing different tissue metabolites and glucose in living tissue have been in development over the last 50 years. These methods have been based upon florescent, near infrared and mid-infrared spectroscopy, Raman spectroscopy, photoacoustics, optical coherence tomography and other techniques. However, none of these techniques that have been tried have proved completely satisfactory.
Another organic component lending itself to optical material concentration sensing involves is human skin. The defense mechanisms of human skin are based on the action of antioxidant substances such as carotenoids, vitamins and enzymes. Beta carotene and lycopene represent more than 70% of the carotenoids in the human organism. The topical or systematic application of beta carotene and lycopene is a general strategy for improving the defense system of the human body. The evaluation and optimization of this treatment requires the measurement of the b-carotene and lycopene concentrations in human tissue, especially in the human skin as the barrier to the environment.
Thus, an improved non-invasive technique enabling the detection of concentrations of various materials within a human body or other types of samples would have a number of applications within the medical field.
The present invention, as disclosed and describe herein, in one aspect thereof, comprises an apparatus for measuring the concentration of a material within a sample. Signal generation circuitry generates a first signal having at least one orbital angular momentum applied thereto and applies the first signal to the sample. A detector for receives the first signal after it passes through the sample and determines the concentration of the material within the sample based on a detected value of orbital angular momentum with the first signal received from the sample.
For a more complete understanding, reference is now made to the following description taken in conjunction with the accompanying Drawings in which:
a-9c illustrate the differences between signals having different orbital angular momentum applied thereto;
a-14d illustrate various holograms for use in applying an orbital angular momentum to a plane wave signal;
Referring now to the drawings, wherein like reference numbers are used herein to designate like elements throughout, the various views and embodiments of system and method for making concentration measurements within a sample material using orbital angular momentum are illustrated and described, and other possible embodiments are described. The figures are not necessarily drawn to scale, and in some instances the drawings have been exaggerated and/or simplified in places for illustrative purposes only. One of ordinary skill in the art will appreciate the many possible applications and variations based on the following examples of possible embodiments.
Referring now to the drawings, and more particularly to
Referring now also to ω and a linear momentum of ±
k which is directed along the light beam axis 204 perpendicular to the wavefront. Independent of the frequency, each photon 202 within the light beam has a spin angular momentum 206 of ±
aligned parallel or antiparallel to the direction of light beam propagation. Alignment of all of the photons 202 spins gives rise to a circularly polarized light beam. In addition to the circular polarization, the light beams also may carry an orbital angular momentum 208 which does not depend on the circular polarization and thus is not related to photon spin.
Lasers are widely used in optical experiments as the source of well-behaved light beams of a defined frequency. A laser may be used for providing the light beam 104 as described with respect to
For example, beams that have l intertwined helical fronts are also solutions of the wave equation. The structure of these complicated beams is difficult to visualize, but their form is familiar from the l=3 fusilli pasta. Most importantly, the wavefront has a Poynting vector and a wave vector that spirals around the light beam axis direction of propagation as illustrated in
A Poynting vector has an azimuthal component on the wave front and a non-zero resultant when integrated over the beam cross-section. The spin angular momentum of circularly polarized light may be interpreted in a similar way. A beam with a circularly polarized planer wave front, even though it has no orbital angular momentum, has an azimuthal component of the Poynting vector proportional to the radial intensity gradient. This integrates over the cross-section of the light beam to a finite value. When the beam is linearly polarized, there is no azimuthal component to the Poynting vector and thus no spin angular momentum.
Thus, the momentum of each photon 202 within the light beam 104 has an azimuthal component. A detailed calculation of the momentum involves all of the electric fields and magnetic fields within the light beam, particularly those electric and magnetic fields in the direction of propagation of the beam. For points within the beam, the ratio between the azimuthal components and the z components of the momentum is found to be l/kr. The linear momentum of each photon 202 within the light beam 104 is given by k, so if we take the cross product of the azimuthal component within a radius vector, r, we obtain an orbital momentum for a photon 202 of l
. Note also that the azimuthal component of the wave vectors is l/r and independent of the wavelength.
Referring now to ) per photon.
Using the orbital angular momentum state of the transmitted energy signals, physical information can be embedded within the electromagnetic radiation transmitted by the signals. The Maxwell-Heaviside equations can be represented as:
where ∇ is the del operator, E is the electric field intensity and B is the magnetic flux density. Using these equations, we can derive 23 symmetries/conserve quantities from Maxwell's original equations. However, there are only ten well-known conserve quantities and only a few of these are commercially used. Historically if Maxwell's equations where kept in their original quaternion forms, it would have been easier to see the symmetries/conserved quantities, but when they were modified to their present vectorial form by Heaviside, it became more difficult to see such inherent symmetries in Maxwell's equations.
The conserved quantities and the electromagnetic field can be represented according to the conservation of system energy and the conservation of system linear momentum. Time symmetry, i.e. the conservation of system energy can be represented using Poynting's theorem according to the equations:
The space symmetry, i.e., the conservation of system linear momentum representing the electromagnetic Doppler shift can be represented by the equations:
The conservation of system center of energy is represented by the equation:
Similarly, the conservation of system angular momentum, which gives rise to the azimuthal Doppler shift is represented by the equation:
For radiation beams in free space, the EM field angular momentum Jem can be separated into two parts:
Jem=ε0∫V′d3x′(E×A)+ε0∫V′d3x′Ei[(x′−x0)×∇]Ai
For each singular Fourier mode in real valued representation:
The first part is the EM spin angular momentum Sem, its classical manifestation is wave polarization. And the second part is the EM orbital angular momentum Lem its classical manifestation is wave helicity. In general, both EM linear momentum Pem, and EM angular momentum Jem=Lem+Sem are radiated all the way to the far field.
By using Poynting theorem, the optical vorticity of the signals may be determined according to the optical velocity equation:
where S is the Poynting vector
S=¼(E×H*+E*×H),
and U is the energy density
U=¼(ε|E|2+μ0|H|2),
with E and H comprising the electric field and the magnetic field, respectively, and ε and μ0 being the permittivity and the permeability of the medium, respectively. The optical vorticity V may then be determined by the curl of the optical velocity according to the equation:
Referring now to
In the plane wave situation, illustrated in
Within a circular polarization as illustrated at 706, the signal vectors 712 are 90 degrees to each other but have the same magnitude. This causes the signal to propagate as illustrated at 706 and provide the circular polarization 714 illustrated in
The situation in
a-9c illustrate the differences in signals having a different helicity (i.e., orbital angular momentum applied thereto). The differing helicities would be indicative of differing concentration of materials within a sample that a beam was being passed through. By determining the particular orbital angular momentum signature associated with a signal, the concentration amounts of the material could be determined. Each of the spiraling Poynting vectors associated with a signal 902, 904 and 906 provides a different-shaped signal. Signal 902 has an orbital angular momentum of +1, signal 904 has an orbital angular momentum of +3 and signal 906 has an orbital angular momentum of −4. Each signal has a distinct orbital angular momentum and associated Poynting vector enabling the signal to be indicative of a particular concentration of material that is associated with the detected orbital angular momentum. This allows determinations of concentrations of various types of materials to be determined from a signal since the orbital angular momentums are separately detectable and provide a unique indication of the concentration of the particular material that has affected the orbital angular momentum of the signal transmitted through the sample material.
Referring now to
A series of output waves 1112 from the sample material 1110 exit the sample and have a particular orbital angular momentum imparted thereto as a result of the concentration of the particular material under study within the sample material 1110. The output waves 1112 are applied to a matching module 1114 that includes a mapping aperture for amplifying a particular orbital angular momentum generated by the specific material under study. The matching module 1114 will amplify the orbital angular momentums associated with the particular concentration of material that is detected by the apparatus. The amplified OAM waves 1116 are provided to a detector 1118. The detector 1118 detects OAM waves relating to the concentration of a material within the sample and provides this concentration information to a user interface/processor 1120. The user interface/processor 1120 interprets the concentration information and provides relevant concentration indication to an individual or a recording device.
Referring now to
The OAM generation module 1106 processes the incoming plane wave 1104 and imparts a known orbital angular momentum onto the plane waves 1104 provided from the emitter 1102. The OAM generation module 1106 generates twisted or helical electromagnetic, optic, acoustic or other types of particle waves from the plane waves of the emitter 702. A helical wave 1108 is not aligned with the direction of propagation of the wave but has a procession around direction of propagation as shown in
The fixed orbital angular momentum generator 1302 may in one embodiment comprise a holographic image for applying the fixed orbital angular momentum to the plane wave 1104 in order to generate the OAM twisted wave 904. Various types of holographic images may be generated in order to create the desired orbital angular momentum twist to an optical signal that is being applied to the orbital angular momentum generator 1102. Various examples of these holographic images are illustrated in
Most commercial lasers emit an HG00 (Hermite-Gaussian) mode 1502 (
The cylindrical symmetric solution upl (r,φ,z) which describes Laguerre-Gaussian beams, is given by the equation:
Where zR is the Rayleigh range, w(z) is the radius of the beam, LP is the Laguerre polynomial, C is a constant, and the beam waist is at z=0.
In its simplest form, a computer generated hologram is produced from the calculated interference pattern that results when the desired beam intersects the beam of a conventional laser at a small angle. The calculated pattern is transferred to a high resolution holographic film. When the developed hologram is placed in the original laser beam, a diffraction pattern results. The first order of which has a desired amplitude and phase distribution. This is one manner for implementing the OAM generation module 1106. A number of examples of holographic images for use within a OAM generation module are illustrated with respect to
There are various levels of sophistication in hologram design. Holograms that comprise only black and white areas with no grayscale are referred to as binary holograms. Within binary holograms, the relative intensities of the two interfering beams play no role and the transmission of the hologram is set to be zero for a calculated phase difference between zero and π, or unity for a phase difference between π and 2π. A limitation of binary holograms is that very little of the incident power ends up in the first order diffracted spot, although this can be partly overcome by blazing the grating. When mode purity is of particular importance, it is also possible to create more sophisticated holograms where the contrast of the pattern is varied as a function of radius such that the diffracted beam has the required radial profile.
A plane wave shining through the holographic images 1402 will have a predetermined orbital angular momentum shift applied thereto after passing through the holographic image 1402. OAM generator 1302 is fixed in the sense that a same image is used and applied to the beam being passed through the holographic image. Since the holographic image 1402 does not change, the same orbital angular momentum is always applied to the beam being passed through the holographic image 1402. While
In another example of a holographic image illustrated in
Referring now to
This may be achieved in any number of fashions. In one embodiment, illustrated in
Referring now to
Referring now to is the beams orbital angular momentum per photon within the output signal. For each l, the left column 1902 is the light beam's instantaneous phase. The center column 1904 comprises the angular intensity profiles and the right column 1906 illustrates what occurs when such a beam interferes with a plane wave and produces a spiral intensity pattern. This is illustrated for orbital angular momentums of −1, 0, 1, 2 and 3 within the various rows of
Referring now to
Referring now to
Referring now to
The sample 1110 may include detectable items such as organic compounds including carbohydrates, lipids (cylcerol and fatty acids), nucleic acids (C,H,O,N,P) (RNA and DNA) or various types of proteins such as polyour of amino NH2 and carboxyl COOH or aminos such as tryptophan, tyrosine and phenylalanine Various chains within the samples 1110 may also be detected such as monomers, isomers and polymers. Enzymes such as ATP and ADP within the samples may be detected. Substances produced or released by glands of the body may be in the sample and detected. These include items released by the exocrine glands via tube/ducts, endocrine glands released directly into blood samples or hormones. Various types of glands that may have their secretions detected within a sample 1110 include the hypothalamus, pineal and pituitary glands, the parathyroid and thyroid and thymus, the adrenal and pancreas glands of the torso and the hormones released by the ovaries or testes of a male or female.
The sample 1110 may also be used for detecting various types of biochemical markers within the blood and urine of an individual such as melanocytes and keratinocytes. The sample 1110 may include various parts of the body to detect defense substances therein. For example, with respect to the skin, the sample 1110 may be used to detect carotenoids, vitamins, enzymes, b-carotene and lycopene. With respect to the eye pigment, the melanin/eumelanin, dihydroxyindole or carboxylic may be detected. The system may also detect various types of materials within the body's biosynthetic pathways within the sample 1110 including hemoglobin, myoglobin, cytochromes, and porphyrin molecules such as protoporphyrin, coporphyrin, uroporphyrin and nematoporphyrin. The sample 1110 may also contain various bacterias to be detected such as propion bacterium, acnes. Also various types of dental plaque bacteria may be detected such as porphyromonos gingivitis, prevotella intremedi and prevotella nigrescens. The sample 1110 may also be used for the detection of glucose in insulin within a blood sample 1110.
The orbital angular momentum within the beams provided within the sample 1110 may be transferred from light to matter molecules depending upon the rotation of the matter molecules. When a circularly polarized laser beam with a helical wave front traps a molecule in an angular ring of light around the beam axis, one can observe the transfer of both orbital and spin angular momentum. The trapping is a form of optical tweezing accomplished without mechanical constraints by the ring's intensity gradient. The orbital angular momentum transferred to the molecule makes it orbit around the beam axis as illustrated at 2302 of
The output OAM wave 1112 from the sample 1110 will have an orbital angular momentum associated therewith that is different from the orbital angular momentum provided on the input OAM wave 1108. The difference in the output OAM wave 1112 will depend upon the material contained within the sample 1110 and the concentration of these materials within the sample 1110. Differing materials of differing concentration will have unique orbital angular momentums associated therewith. Thus, by analyzing the particular orbital angular momentum signature associated with the output OAM wave 1112, determinations may be made as to the materials present within the sample 1110 and the concentration of these materials within the sample may also be determined.
Referring now to
Referring now to
Referring now to
This overall process can be more particularly illustrated in
Δφ=φ1−φ−1=f(l,L,C)
Where l is orbital angular momentum number, L is the path length of the sample and C is the concentration of the material being detected.
Thus, since the length of the sample L is known and the orbital angular momentum may be determined using the process described herein, these two pieces of information may be able to calculate a concentration of the material within the provided sample.
The above equation may be utilized within the user interface more particularly illustrated in
Referring now to
Alternatively, when information is compiled from multiple devices 3002 within the public cloud 3006, this information may be provided directly to the public cloud 3006 from the individual devices 3002 or through the private clouds 3004 of the associated network devices 3002. Utilizing this information within the public cloud 3006 large databases may be established within servers 3008 associated with the public cloud 3006 to enable large scale analysis of various health related issues associated with the information processed from each of the individual devices 3002. This information may be used for analyzing public health issues.
Thus, the user interface 1120 in addition to including the algorithm 2912 for determining concentration information 2904 will include a wireless interface 2906 enabling the collected information to be wirelessly transmitted over the public or private cloud as described with respect to
Referring now to
In this manner concentrations of various types of material as describe herein may be determined utilizing the orbital angular momentum signatures of the samples under study and the detection of these materials or their concentrations within the sample determine as described.
It will be appreciated by those skilled in the art having the benefit of this disclosure that this system and method for making concentration measurements within a sample material using orbital angular momentum provides a non-invasive manner for detecting material concentration. It should be understood that the drawings and detailed description herein are to be regarded in an illustrative rather than a restrictive manner, and are not intended to be limiting to the particular forms and examples disclosed. On the contrary, included are any further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments apparent to those of ordinary skill in the art, without departing from the spirit and scope hereof, as defined by the following claims. Thus, it is intended that the following claims be interpreted to embrace all such further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments.
This application claims benefit of U.S. Provisional Application No. 61/951,834, filed Mar. 12, 2014, entitled CONCENTRATION MEASUREMENTS USING PHOTON ORBITAL ANGULAR MOMENTUM, the specification of which is incorporated by reference herein in its entirety.
Number | Name | Date | Kind |
---|---|---|---|
3459466 | Giordmaine | Aug 1969 | A |
3614722 | Jones | Oct 1971 | A |
4379409 | Primbsch et al. | Apr 1983 | A |
4503336 | Hutchin et al. | Mar 1985 | A |
4736463 | Chavez | Apr 1988 | A |
4862115 | Lee et al. | Aug 1989 | A |
5051754 | Newberg | Sep 1991 | A |
5220163 | Toughlian et al. | Jun 1993 | A |
5222071 | Pezeshki et al. | Jun 1993 | A |
5272484 | Labaar | Dec 1993 | A |
5543805 | Thaniyavarn | Aug 1996 | A |
5555530 | Meehan | Sep 1996 | A |
6337659 | Kim | Jan 2002 | B1 |
6992829 | Jennings et al. | Jan 2006 | B1 |
7577165 | Barrett | Aug 2009 | B1 |
7729572 | Pepper et al. | Jun 2010 | B1 |
7792431 | Jennings et al. | Sep 2010 | B2 |
8432884 | Ashrafi | Apr 2013 | B1 |
8503546 | Ashrafi | Aug 2013 | B1 |
8559823 | Izadpanah et al. | Oct 2013 | B2 |
8811366 | Ashrafi | Aug 2014 | B2 |
9077577 | Ashrafi | Jul 2015 | B1 |
20020164806 | Collins | Nov 2002 | A1 |
20040196465 | Arnold et al. | Oct 2004 | A1 |
20050254826 | Jennings et al. | Nov 2005 | A1 |
20050259914 | Padgett et al. | Nov 2005 | A1 |
20060126183 | Hasman | Jun 2006 | A1 |
20080037004 | Shamir et al. | Feb 2008 | A1 |
20100013696 | Schmitt et al. | Jan 2010 | A1 |
20100317959 | Elgort et al. | Dec 2010 | A1 |
20100327866 | Albu et al. | Dec 2010 | A1 |
20120207470 | Djordjevic et al. | Aug 2012 | A1 |
20130027774 | Bovino et al. | Jan 2013 | A1 |
20140353475 | Meyers et al. | Dec 2014 | A1 |
20140355624 | Li et al. | Dec 2014 | A1 |
20150098697 | Marom et al. | Apr 2015 | A1 |
Number | Date | Country |
---|---|---|
WO 2011028109 | Mar 2011 | WO |
WO 2012172471 | Dec 2012 | WO |
WO 2013179023 | Dec 2013 | WO |
WO 2013186648 | Dec 2013 | WO |
Entry |
---|
Darla et al., “Optical twisters: beams having twists in both phase and amplitude,” 2010, Complex Light and Optical Forces IV, edited by Galvez et al., Proc. of SPIE vol. 7613, pp. 761304-1 to 761304-8. |
Zhang et al., “High-dimensional orbital angular momentum entanglement concentration based on Laguerre-Gaussian mode selection,” 2013, Laser Physics Letters, 10, 5 pages. |
PCT: International Search Report and Written Opinion of PCT/US2015/019177 (related application), Jun. 25, 2015, 8 pgs. |
Solyman Ashrafi, Channeling Radiation of Electrons in Crystal Lattices, Essays on Classical and Quantum Dynamics, Gordon and Breach Science Publishers, 1991. |
Solyman Ashrafi, Solar Flux Forecasting Using Mutual Information with an Optimal Delay, Advances in the Astronautical Sciences, American Astronautical Society, vol. 84 Part II, 1993. |
Solyman Ashrafi, PCS system design issues in the presence of microwave OFS, Electromagnetic Wave Interactions, Series on Stability, Vibration and Control of Systems, World Scientific, Jan. 1996. |
Solyman Ashrafi, Performance Metrics and Design Parameters for an FSO Communications Link Based on Multiplexing of Multiple Orbital-Angular-Momentum Beams, Globecom2014 OWC Workshop, 2014. |
Solyman Ashrafi, Optical Communications Using Orbital Angular Momentum Beams, Adv. Opt. Photon. 7, 66-106, Advances in Optics and Photonic, 2015. |
Solyman Ashrafi, Performance Enhancement of an Orbital-Angular-Momentum-Based Free-Space Optical Communication Link through Beam Divergence Controlling, OSA Technical Digest (online), paper M2F.6. The Optical Society, 2015. |
Solyman Ashrafi, 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 (online), paper JTh2A.63. The Optical Society, 2014. |
Solyman Ashrafi, 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, Apr. 2015. |
Solyman Ashrafi, Performance Metrics and Design Considerations for a Free-Space Optical Orbital-Angular-Momentum-Multiplexed Communication Link, The Optical Society, vol. 2, No. 4, Apr. 2015. |
Solyman Ashrafi, Demonstration of Distance Emulation for an Orbital-Angular-Momentum Beam. OSA Technical Digest (online), paper STh1F.6. The Optical Society, 2015. |
Solyman Ashrafi, Free-Space Optical Communications Using Orbital-Angular-Momentum Multiplexing Combined with MIMO-Based Spatial Multiplexing. Optics Letters, vol. 40, No. 18, Sep. 4, 2015. |
Solyman Ashrafi, 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 (online), paper SW1M.6. The Optical Society, 2015. |
Solyman Ashrafi, 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 (online), paper SW4M.5. The Optical Society, 2015. |
Solyman Ashrafi, 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. |
Solyman Ashrafi, 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 (online), paper JTh2A.63. The Optical Society, 2015. |
Solyman Ashrafi, 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. |
Solyman Ashrafi, Performance Metrics for a Free-Space Communication Link Based on Multiplexing of Multiple Orbital Angular Momentum Beams with Higher Order Radial Indice. OSA Technical Digest (online), paper JTh2A.62. The Optical Society, 2015. |
Solyman Ashrafi, 400-Gbit/s Free-Space Optical Communications Link Over 120-meter Using Multiplexing of 4 Collocated Orbital-Angular-Momentum Beams. OSA Technical Digest (online), paper M2F.1. The Optical Society, 2015. |
Solyman Ashrafi, 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, Dec. 2014. |
Solyman Ashrafi, 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), Aug. 4-7, 2015, New York USA. |
Wang et al: “Terabit free-space data transmission employing orbital angular momentum multiplexing”, Nature Photonics, vol. 6, Jul. 2012, pp. 488-496. |
Solyman Ashrafi, An Information Theoretic Framework to Increase Spectral Efficiency, IEEE Transaction on Information Theory, vol. XX, No. Y, Oct. 2014, Dallas, Texas. |
H. Yao et al, Patch Antenna Array for the Generation of Millimeter-wave Hermite-Gaussian Beams, IEEE Antennas and Wireless Propagation Letters, (pending publication). |
Yongxiong Ren et al, Experimental Investigation of Data Transmission Over a Graded-index Multimode Fiber Using the Basis of Orbital Angular Momentum Modes (pending publication). |
M. Nouri et al., Perturbations of Laguerre-Gaussian Beams by Chiral Molecules (pending publication). |
Solyman Ashrafi, Acoustically induced stresses in elastic cylinders and their visualization, The Journal of the Acoustical Society of America 82(4):1378-1385, Sep. 1987. |
Solyman Ashrafi, Splitting of channeling-radiation peaks in strained-layer superlattices, Journal of the Optical Society of America B 8(12), Nov. 1991. |
Number | Date | Country | |
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20150260650 A1 | Sep 2015 | US |
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61951834 | Mar 2014 | US |