scholarly journals Frequency Division Multiplexing of Terahertz Waves Realized by Diffractive Optical Elements

2021 ◽  
Vol 11 (14) ◽  
pp. 6246
Author(s):  
Paweł Komorowski ◽  
Patrycja Czerwińska ◽  
Mateusz Kaluza ◽  
Mateusz Surma ◽  
Przemysław Zagrajek ◽  
...  
Keyword(s):  
Frequency Division Multiplexing ◽  
Diffractive Optical Elements ◽  
Frequency Division ◽  
Terahertz Waves ◽  
Optical Elements ◽  
Telecommunication Systems ◽  
Wide Range ◽  
The Future ◽  
Wireless Telecommunication ◽  
Finite Distance

Recently, one of the most commonly discussed applications of terahertz radiation is wireless telecommunication. It is believed that the future 6G systems will utilize this frequency range. Although the exact technology of future telecommunication systems is not yet known, it is certain that methods for increasing their bandwidth should be investigated in advance. In this paper, we present the diffractive optical elements for the frequency division multiplexing of terahertz waves. The structures have been designed as a combination of a binary phase grating and a converging diffractive lens. The grating allows for differentiating the frequencies, while the lens assures separation and focusing at the finite distance. Designed structures have been manufactured from polyamide PA12 using the SLS 3D printer and verified experimentally. Simulations and experimental results are shown for different focal lengths. Moreover, parallel data transmission is shown for two channels of different carrier frequencies propagating in the same optical path. The designed structure allowed for detecting both signals independently without observable crosstalk. The proposed diffractive elements can work in a wide range of terahertz and sub-terahertz frequencies, depending on the design assumptions. Therefore, they can be considered as an appealing solution, regardless of the band finally used by the future telecommunication systems.

scholarly journals Resonant diffraction gratings with polarization-dependent efficiencies

2020 ◽  
Vol 238 ◽  
pp. 05002
Author(s):  
Julian Wüster ◽  
Patrick Feßer ◽  
Arne Behrens ◽  
Stefan Sinzinger
Keyword(s):  
Manufacturing Process ◽  
Degree Of Freedom ◽  
Experimental Results ◽  
Optical Systems ◽  
Subwavelength Structures ◽  
Diffractive Optical Elements ◽  
Optical Elements ◽  
Additional Degree ◽  
Subwavelength Grating ◽  
Wide Range

Subwavelength-structures with different fill factors in the lateral dimensions result in unique phase shifts for the different polarization states of transmitted light. By using this additional degree of freedom for diffractive optical elements, we yield additional functionalities for compact optical systems with DOEs. As a fully operable example we present a binary subwavelength-grating which acts as a polarizing beamsplitter for TE- and TM-polarization over a wide range of incidence angles. We show our design approach, the manufacturing process with Soft-UV-Nanoimprint-Technology, as well as experimental results. We will also lay out possibilities for the design and application of multilevel polarization-functionalized gratings.

scholarly journals Optimization of THz diffractive optical elements thickness

2018 ◽  
Vol 10 (4) ◽  
pp. 115 ◽  
Author(s):  
Mateusz Surma ◽  
Izabela Ducin ◽  
Maciej Sypek ◽  
Przemyslaw Zagrajek ◽  
Agnieszka Siemion
Keyword(s):  
Materials Science ◽  
Phase Distribution ◽  
Extreme Ultraviolet ◽  
Fresnel Lens ◽  
Optical Devices ◽  
Terahertz Wave ◽  
Diffractive Optical Elements ◽  
Terahertz Waves ◽  
Optical Elements ◽  
Absorbing Materials

Diffractive optical elements (DOEs) are strictly related to the design wavelength due to the fact that they must introduce particular phase delay of the wavefront propagating through the structure. Mostly the attenuation of the material is not taken into account. In this article we propose to optimize thickness of the DOE by reducing introduced phase retardation but also attenuation. The efficiency of DOEs is determined by the method of coding phase distribution and can be easily measured by using diffraction orders of corresponding diffraction grating. Here, we analyze binary phase diffraction gratings with assumed attenuation. Full Text: PDF ReferencesJ.-L. Coutaz, Optoélectronique térahertz (Les Ulis CEDEX A, France, EDP Sciences 2012). DirectLink D. Headland, Y. Monnai, D. Abbott, C. Fumeaux,and W. Withayachumnankul, "Tutorial: Terahertz beamforming, from concepts to realizations", APL Photonics 3, 5 (2018). CrossRef S. F. Busch, M. Weidenbach, M. Frey, F. Schäfer, T. Probst, nd M. Koch, "A 3D-Printable Polymer-Metal Soft-Magnetic Functional Composite—Development and Characterization", Journal of Infrared, Millimeter, and Terahertz Waves 35, 12 (2014) CrossRef A. Siemion, P. Kostrowiecki-Lopata, A. Pindur, P. Zagrajek, M. Sypek, "Paper on Designing Costless THz Paper Optics", Advances in Materials Science and Engineering 2016, 9615698 (2016). CrossRef A. Siemion, A. Siemion, M. Makowski, J. Suszek, J. Bomba, A. Czerwinski, F. Garet, J.-L. Coutaz, and M. Sypek, "Diffractive paper lens for terahertz optics", Opt. Lett. 37, 4320–4322 (2012). CrossRef J.-L. Coutaz, F. Garet, E. Bonnet, A. V. Tishchenko, O. Parriaux, and M. Nazarov, "Grating Diffraction Effects in the THz Domain", Acta Phys. Pol. A 107, 26-37 (2005). CrossRef M. S. Heimbeck, P. J. Reardon, J. Callahan, and H. O. Everitt, "Transmissive quasi-optical Ronchi phase grating for terahertz frequencies", Opt. Lett. 35, 21 (2010). CrossRef D. Li, S. Shu, F. Li, G. Ma, Y. Dai, and H. Ma, "Anomalous transmission of terahertz wave through one-dimensional lamellar metallic grating", Opt. Commun. 284, 10-11 (2011). CrossRef X. Li, and S. F. Yu, "Diffraction Characteristics of Concentric Circular Metal Grating Operating at Terahertz Regime", IEEE Journal of Quantum Electronics 46, 6 (2010). CrossRef B. Nöhammer, C. David, J. Gobrecht, and H. P. Herzig, "Optimized staircase profiles for diffractive optical devices made from absorbing materials", Opt. Lett. 28(13), 1087-1089 (2003). CrossRef V. Deuter, M. Grochowicz, S. Brose, J. Biller, S. Danylyuk, T. Taubner, D. Grutzmacher, and L. Juschkin, "Holographic masks for computational proximity lithography with EUV radiation", International Conference on Extreme Ultraviolet Lithography 2018 10809, 108091A (2018). CrossRef J. W. Goodman, Introduction to Fourier optics (Greenwood Village, USA, Roberts & Company Publishers 2005). DirectLink W. B. Veldkamp, "Optimized staircase profiles for diffractive optical devices made from absorbing materials", Appl. Opt. 21(17), 3209-3212W (1982). CrossRef W. B. Veldkamp, and C. J. Kastner, "Beam profile shaping for laser radars that use detector arrays", Appl. Opt. 21(2), 345-356 (1982). CrossRef https://www.mcortechnologies.com/de/3d-drucker/mcor-iris/ DirectLinkM. Sypek, M. Makowski, E. Hérault, A. Siemion, A. Siemion, J. Suszek, F. Garet, and J.-L. Coutaz, "Highly efficient broadband double-sided Fresnel lens for THz range", Opt. Lett. 37, 12 (2012). CrossRef

scholarly journals Upgrading Physical Layer of Multi-Carrier OGFDM Waveform for Improving Wireless Channel Capacity of 5G Mobile Networks and Beyond

Information ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 35
Author(s):  
Mohammad R. Kadhum
Keyword(s):  
Channel Capacity ◽  
Transmission Rate ◽  
Wireless Channel ◽  
Mobile Technologies ◽  
Frequency Division Multiplexing ◽  
Interference Avoidance ◽  
Frequency Division ◽  
Bit Rate ◽  
Bit Loading ◽  
The Future

On the brink of sophisticated generations of mobile starting with the fifth-generation (5G) and moving on to the future mobile technologies, the necessity for developing the wireless telecommunications waveform is extremely required. The main reason beyond this is to support the future digital lifestyle that tends principally to maximize wireless channel capacity and number of connected users. In this paper, the upgraded design of the multi-carrier orthogonal generalized frequency division multiplexing (OGFDM) that aims to enlarge the number of mobile subscribers yet sustaining each one with a high transmission capacity is presented, explored, and evaluated. The expanded multi-carrier OGFDM can improve the performance of the future wireless network that targets equally the broad sharing operation (scalability) and elevated transmission rate. From a spectrum perspective, the upgraded OGFDM can manipulate the side effect of the increased number of network subscribers on the transmission bit-rate for each frequency subcarrier. This primarily can be achieved by utilizing the developed OGFDM features, like acceleration ability, filter orthogonality, interference avoidance, subcarrier scalability, and flexible bit loading. Consequently, the introduced OGFDM can supply lower latency, better BW efficiency, higher robustness, wider sharing, and more resilient bit loading than the current waveform. To highlight the main advantages of the proposed OGFDM, the system performance is compared with the initial design of the multicarrier OGFDM side by side with the 5G waveform generalized frequency division multiplexing (GFDM). The experimented results show that by moving from both the conventional OGFDM and GFDM with 4 GHz to the advanced OGFDM with 6 GHz, the gained channel capacity is improved. Because of the efficient use of Hilbert filters and improved rate of sampling acceleration, the upgraded system can gain about 3 dB and 1.5 dB increments in relative to the OGFDM and GFDM respectively. This, as a result, can maximize mainly the overall channel capacity of the enhanced OGFDM, which in turn can raise the bit-rate of each user in the mobile network. In addition, by employing the OGFDM with the dual oversampling, the achieved channel capacity in worst transmission condition is increased to around six and twelve times relative to the OGFDM and GFDM with the normal oversampling. Furthermore, applying the promoted OGFDM with the adaptive modulation comes up with maximizing the overall channel capacity up to around 1.66 dB and 3.32 dB compared to the initial OGFDM and GFDM respectively. A MATLAB simulation is applied to evaluate the transmission performance in terms of the channel capacity and the bit error rate (BER) in an electrical back-to-back wireless transmission system.

scholarly journals ADVANTAGES OF OPTICAL ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING IN COMMUNICATIONS SYSTEMS

2016 ◽  
Vol 2 ◽  
pp. 27-33
Author(s):  
Ali Abdourahamane
Keyword(s):  
Optical Communication ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Optical Signal ◽  
Optical Systems ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Communications Systems ◽  
Wide Range ◽  
Optical Communication Systems

The role of the optical transmitter is to generate the optical signal, impose the information bearing signal, and launch the modulated signal into the optical fiber. The semiconductor light sources are commonly used in state-of-the-art optical communication systems. Optical communication systems has become one of the important systems after the advent of telephone, internet, radio networks in the second half of the 20th century. The development of optical communication was caused primarily by the rapidly rising demand for Internet connectivity. Orthogonal frequency-division multiplexing (OFDM) belongs to a wide class of multicarrier modulation. Orthogonal frequency-division multiplexing has succeeded in a wide range of applications in the wireless communication domain from video/audio digital broadcasting to wireless local area networks (LANs). Although their very low loss compared to that of the wireless counterpart, optical systems still need renovation for spans commonly less than150 Km. In this paper advantages of optical orthogonal frequency division multiplexing in communications systems will explained.

Study and Simulation Analysis of OFDM System Based on Simulink

2013 ◽  
Vol 706-708 ◽  
pp. 1967-1970
Author(s):  
Tong Qiang Li ◽  
Li Gang Xu
Keyword(s):  
Simulation Model ◽  
Communication System ◽  
Orthogonal Frequency Division Multiplexing ◽  
Simulation Analysis ◽  
Performance Characteristics ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Ofdm System ◽  
The Future ◽  
Simulation Results

Orthogonal Frequency Division Multiplexing(OFDM) is going to become the most important technique in the future communication system. The paper presents the principle of OFDM,establishes a simulation model of OFDM communication system based on simulink.By utilizing the system,we briefly analyse the simulation results and conclude the the performance characteristics of OFDM system.

scholarly journals PROFESSOR S.V. KARPEEV IS 60 YEARS OLD

2016 ◽  
Author(s):  
Eduard I. Kolomiets ◽  
Keyword(s):  
Image Processing ◽  
Diffractive Optical Elements ◽  
Optical Elements ◽  
Russian Academy Of Sciences ◽  
Wide Range ◽  
Mathematical Sciences ◽  
Academy Of Sciences

The article presents a summary of scientific and pedagogical activity of a leading researcher of the Institute of Image Processing Systems of Russian Academy of Sciences, Doctor of Physical and Mathematical Sciences, Professor Sergey Vladimirovich Karpeev, a well known expert in the field of computer optics. The celebrant`s contribution to the development of methods of research of diffractive optical elements and the use of computer optics methods to solve a wide range of problems is being analyzed in the article.

scholarly journals Neural-network based approach to optimize THz computer generated holograms

2021 ◽  
Vol 13 (4) ◽  
pp. 88
Author(s):  
Mateusz Surma ◽  
Mateusz Kaluza ◽  
Patrycja Czerwińska ◽  
Paweł Komorowski ◽  
Agnieszka Siemion
Keyword(s):  
Neural Network ◽  
Optical Element ◽  
Computational Design ◽  
Additive Manufacture ◽  
Diffractive Optical Elements ◽  
Terahertz Waves ◽  
Neural Network Approach ◽  
Optical Elements ◽  
Industrial Sectors ◽  
Terahertz Technology

Terahertz (THz) optics often encounters the problem of small f number values (elements have relatively small diameters comparing to focal lengths). The need to redirect the THz beam out of the optical axis or form particular intensity distributions resulted in the application of iterative holographic methods to design THz diffractive elements. Elements working on-axis do not encounter significant improvement while using iterative holographic methods, however, for more complicated distributions the difference becomes meaningful. Here, we propose a totally different approach to design THz holograms, utilizing a neural network based algorithm, suitable also for complicated distributions. Full Text: PDF ReferencesY. Tao, A. Fitzgerald and V. Wallace, "Non-Contact, Non-Destructive Testing in Various Industrial Sectors with Terahertz Technology", Sensors, 20(3), 712 (2020). CrossRef J. O'Hara, S. Ekin, W. Choi and I. Song, "A Perspective on Terahertz Next-Generation Wireless Communications", Technologies, 7(2), 43 (2019). CrossRef L. Yu et al., "The medical application of terahertz technology in non-invasive detection of cells and tissues: opportunities and challenges", RSC Advances, 9(17), 9354 (2019). CrossRef A. Siemion, "The Magic of Optics—An Overview of Recent Advanced Terahertz Diffractive Optical Elements", Sensors, 21(1), 100 (2020). CrossRef A. Siemion, "Terahertz Diffractive Optics—Smart Control over Radiation", J. Infrared Millim. Terahertz Waves, 40(5), 477 (2019). CrossRef M. Surma, I. Ducin, P. Zagrajek and A. Siemion, "Sub-Terahertz Computer Generated Hologram with Two Image Planes", Appl. Sci., 9(4), 659 (2019). CrossRef S. Banerji and B.Sensale-Rodriguez, "A Computational Design Framework for Efficient, Fabrication Error-Tolerant, Planar THz Diffractive Optical Elements", Sci. Rep., 9(1), 5801 (2019). CrossRef J. Sun and F. Hu, "Three-dimensional printing technologies for terahertz applications: A review", Int. J. RF. Microw. C. E., 30(1) (2020). CrossRef E. Castro-Camus, M. Koch and A. I. Hernandez-Serrano, "Additive manufacture of photonic components for the terahertz band", J. Appl. Phys., 127(21), 210901 (2020). CrossRef https://community.wolfram.com/groups/-/m/t/2028026?p_%20479%20p_auth=blBtLb5d DirectLink P. Komorowski, et al., "Three-focal-spot terahertz diffractive optical element-iterative design and neural network approach", Opt. Express, 29(7), 11243-11253 (2021) CrossRef M. Sypek, "Light propagation in the Fresnel region. New numerical approach", Opt. Commun., 116(1-3), 43 (1995). CrossRef

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