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Tudor R, Bulzan GA, Kusko M, Kusko C, Avramescu V, Vasilache D, Gavrila R. Multilevel Spiral Axicon for High-Order Bessel-Gauss Beams Generation. Nanomaterials (Basel) 2023; 13:579. [PMID: 36770540 PMCID: PMC9920465 DOI: 10.3390/nano13030579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/20/2023] [Accepted: 01/28/2023] [Indexed: 06/18/2023]
Abstract
This paper presents an efficient method to generate high-order Bessel-Gauss beams carrying orbital angular momentum (OAM) by using a thin and compact optical element such as a multilevel spiral axicon. This approach represents an excellent alternative for diffraction-free OAM beam generation instead of complex methods based on a doublet formed by a physical spiral phase plate and zero-order axicon, phase holograms loaded on spatial light modulators (SLMs), or the interferometric method. Here, we present the fabrication process for axicons with 16 and 32 levels, characterized by high mode conversion efficiency and good transmission for visible light (λ = 633 nm wavelength). The Bessel vortex states generated with the proposed diffractive optical elements (DOEs) can be exploited as a very useful resource for optical and quantum communication in free-space channels or in optical fibers.
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Affiliation(s)
- Rebeca Tudor
- National Institute for Research and Development in Microtechnologies IMT, 077190 Bucharest, Romania
| | - George Andrei Bulzan
- National Institute for Research and Development in Microtechnologies IMT, 077190 Bucharest, Romania
- Faculty of Physics, University of Bucharest, 405 Atomistilor Street, 077125 Magurele, Romania
| | - Mihai Kusko
- National Institute for Research and Development in Microtechnologies IMT, 077190 Bucharest, Romania
| | - Cristian Kusko
- National Institute for Research and Development in Microtechnologies IMT, 077190 Bucharest, Romania
| | - Viorel Avramescu
- National Institute for Research and Development in Microtechnologies IMT, 077190 Bucharest, Romania
| | - Dan Vasilache
- National Institute for Research and Development in Microtechnologies IMT, 077190 Bucharest, Romania
| | - Raluca Gavrila
- National Institute for Research and Development in Microtechnologies IMT, 077190 Bucharest, Romania
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Sachdeva S, Kaur S, Arora R, Sindhwani M, Arora K, Cho W, Joshi GP, Doo IC. Ultra-High Capacity Optical Satellite Communication System Using PDM-256-QAM and Optical Angular Momentum Beams. Sensors (Basel) 2023; 23:786. [PMID: 36679583 PMCID: PMC9865998 DOI: 10.3390/s23020786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/06/2023] [Accepted: 01/07/2023] [Indexed: 06/17/2023]
Abstract
Twisted light beams such as optical angular momentum (OAM) with numerous possible orthogonal states have drawn the prodigious contemplation of researchers. OAM multiplexing is a futuristic multi-access technique that has not been scrutinized for optical satellite communication (OSC) systems thus far, and it opens up a new window for ultra-high-capacity systems. This paper presents the 4.8 Tbps (5 wavelengths × 3 OAM beams × 320 Gbps) ultra-high capacity OSC system by incorporating polarization division multiplexed (PDM) 256-Quadrature amplitude modulation (256-QAM) and OAM beams. To realize OAM multiplexing, Laguerre Gaussian (LG) transverse mode profiles such as LG00, LG140, and LG400 were used in the proposed study. The effects of the receiver's digital signal processing (DSP) module were also investigated, and performance improvement was observed using DSP for its potential to compensate for the effects of dispersion, phase errors, and nonlinear effects using the blind phase search (BPS), Viterbi phase estimation (VPE), and the constant modulus algorithm (CMA). The results revealed that the proposed OAM-OSC system successfully covered the 22,000 km OSC link distance and, out of three OAM beams, fundamental mode LG00 offered excellent performance. Further, a detailed comparison of the proposed system and reported state-of-the-art schemes was performed.
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Affiliation(s)
- Shippu Sachdeva
- School of Electronics and Electrical Engineering, Lovely Professional University, Phagwara 144411, India
| | - Simarpreet Kaur
- Department of Electronics and Communication, Chandigarh University, Mohali 140413, India
| | - Romisha Arora
- Department of Electronics and Communication, Manav Rachna International Institute of Research and Studies, Faridabad 121004, India
| | - Manoj Sindhwani
- School of Electronics and Electrical Engineering, Lovely Professional University, Phagwara 144411, India
| | - Krishan Arora
- School of Electronics and Electrical Engineering, Lovely Professional University, Phagwara 144411, India
| | - Woong Cho
- Department of Software Convergence, Daegu Catholic University, Gyeongsan 38430, Republic of Korea
| | - Gyanendra Prasad Joshi
- Department of Computer Science and Engineering, Sejong University, Seoul 05006, Republic of Korea
| | - Ill Chul Doo
- Artificial Intelligence Education, Hankuk University of Foreign Studies, Dongdaemun-gu, Seoul 02450, Republic of Korea
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Stellinga D, Pietrzyk ME, Glackin JME, Wang Y, Bansal AK, Turnbull GA, Dholakia K, Samuel IDW, Krauss TF. An Organic Vortex Laser. ACS Nano 2018; 12:2389-2394. [PMID: 29298373 DOI: 10.1021/acsnano.7b07703] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Optical vortex beams are at the heart of a number of novel research directions, both as carriers of information and for the investigation of optical activity and chiral molecules. Optical vortex beams are beams of light with a helical wavefront and associated orbital angular momentum. They are typically generated using bulk optics methods or by a passive element such as a forked grating or a metasurface to imprint the required phase distribution onto an incident beam. Since many applications benefit from further miniaturization, a more integrated yet scalable method is highly desirable. Here, we demonstrate the generation of an azimuthally polarized vortex beam directly by an organic semiconductor laser that meets these requirements. The organic vortex laser uses a spiral grating as a feedback element that gives control over phase, handedness, and degree of helicity of the emitted beam. We demonstrate vortex beams up to an azimuthal index l = 3 that can be readily multiplexed into an array configuration.
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Affiliation(s)
- Daan Stellinga
- Department of Physics , University of York , Heslington, York , YO10 5DD , U.K
| | - Monika E Pietrzyk
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy , University of St Andrews , North Haugh, St Andrews , KY16 9SS , U.K
| | - James M E Glackin
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy , University of St Andrews , North Haugh, St Andrews , KY16 9SS , U.K
| | - Yue Wang
- Department of Physics , University of York , Heslington, York , YO10 5DD , U.K
| | - Ashu K Bansal
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy , University of St Andrews , North Haugh, St Andrews , KY16 9SS , U.K
| | - Graham A Turnbull
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy , University of St Andrews , North Haugh, St Andrews , KY16 9SS , U.K
| | - Kishan Dholakia
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy , University of St Andrews , North Haugh, St Andrews , KY16 9SS , U.K
| | - Ifor D W Samuel
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy , University of St Andrews , North Haugh, St Andrews , KY16 9SS , U.K
| | - Thomas F Krauss
- Department of Physics , University of York , Heslington, York , YO10 5DD , U.K
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Abstract
Mammalian fertilization is a complex process that involves gamete recognition, penetration, and fusion. Biochemical studies that identified the role of acrosome components during sperm-ova interaction especially the zona pellucida (ZP) provided major advances in sperm cell biology. Acrosin (a typical serine protease) functions during fertilization in several significant ways which include: a) activation of acrosome components, b) secondary binding with the ZP, and c) hydrolysis of the ZP. However, studies using knockout (KO) acrosin-deficient mice cast doubt on the traditional role of acrosin in fertilization. The KO acrosin-deficient mice exhibit normal fecundity except for delayed fertilization. Despite the doubt cast on the traditional role of acrosin by the KO acrosin-deficient mouse studies, acrosin still remains a major protease involved in multiple processes of fertilization. In this review, we assess the functional profile of acrosin and briefly summarize recent findings on proteases involved in fertilization. We propose a refined scheme for the functional role of acrosin in fertilization. We particularly emphasize the role of acrosin in acrosome exocytosis and activation of other acrosome components based on advanced technology like structural X-ray analysis.
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Affiliation(s)
- Hai-Tao Mao
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
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