FREE-SPACE PROPAGATION OF TERAHERTZ LASER VORTEX BEAMS

Subject and Purpose. Currently, numerous ideas and different methods have been in growth for generating vortex beams — areas of the circular motion of the electromagnetic wave energy flow around the so-called phase singularity points caused by a violation of the wave front topological structure. The...

Full description

Saved in:
Bibliographic Details
Date:2024
Main Authors: Degtyarev, A. V., Dubinin, M. M., Maslov, V. A., Muntean, K. I., Svistunov, O. O.
Format: Article
Language:Ukrainian
Published: Видавничий дім «Академперіодика» 2024
Subjects:
Online Access:http://rpra-journal.org.ua/index.php/ra/article/view/1442
Tags: Add Tag
No Tags, Be the first to tag this record!
Journal Title:Radio physics and radio astronomy

Institution

Radio physics and radio astronomy
id rpra-journalorgua-article-1442
record_format ojs
institution Radio physics and radio astronomy
baseUrl_str
datestamp_date 2024-07-01T12:16:48Z
collection OJS
language Ukrainian
topic terahertz laser
waveguide resonator
spiral phase plate
vortex beams
polarization
radiation propagation
spellingShingle terahertz laser
waveguide resonator
spiral phase plate
vortex beams
polarization
radiation propagation
Degtyarev, A. V.
Dubinin, M. M.
Maslov, V. A.
Muntean, K. I.
Svistunov, O. O.
FREE-SPACE PROPAGATION OF TERAHERTZ LASER VORTEX BEAMS
topic_facet terahertz laser
waveguide resonator
spiral phase plate
vortex beams
polarization
radiation propagation
терагерцовий лазер
хвилевідний резонатор
спіральна фазова пластинка
вихрові пучки
поляризація
поширення випромінювання
format Article
author Degtyarev, A. V.
Dubinin, M. M.
Maslov, V. A.
Muntean, K. I.
Svistunov, O. O.
author_facet Degtyarev, A. V.
Dubinin, M. M.
Maslov, V. A.
Muntean, K. I.
Svistunov, O. O.
author_sort Degtyarev, A. V.
title FREE-SPACE PROPAGATION OF TERAHERTZ LASER VORTEX BEAMS
title_short FREE-SPACE PROPAGATION OF TERAHERTZ LASER VORTEX BEAMS
title_full FREE-SPACE PROPAGATION OF TERAHERTZ LASER VORTEX BEAMS
title_fullStr FREE-SPACE PROPAGATION OF TERAHERTZ LASER VORTEX BEAMS
title_full_unstemmed FREE-SPACE PROPAGATION OF TERAHERTZ LASER VORTEX BEAMS
title_sort free-space propagation of terahertz laser vortex beams
title_alt ПОШИРЕННЯ ТЕРАГЕРЦОВИХ ВИХРОВИХ ЛАЗЕРНИХ ПУЧКІВ У ВІЛЬНОМУ ПРОСТОРІ
description Subject and Purpose. Currently, numerous ideas and different methods have been in growth for generating vortex beams — areas of the circular motion of the electromagnetic wave energy flow around the so-called phase singularity points caused by a violation of the wave front topological structure. The purpose of this work is to obtain analytical expressions describing the nonparaxial diffraction of wave modes of the waveguide resonator of a terahertz laser during the wave mode interaction with a spiral phase plate. The resulting vortex beams are examined for their physical features in free space propagation.Methods and Methodology. The Rayleigh-Sommerfeld vector theory is adopted to consider the propagation of vortex laser beams generated by wave modes of the quasi-optical waveguide cavity when interacting with a spiral phase plate in different diffraction zones.Results. For the first time, analytical expressions have been obtained to describe the nonparaxial diffraction of wave modes of the waveguide resonator of a terahertz laser, when resonator modes interact with a spiral phase plate at different topological charges, n. The physical features of the resulting vortex beams were studied in their free space propagation. It has been shown that a spiral phase plate modifies the structure of the linearly polarized EH₁₁ mode so that the original (n=0) intensity profile with the maximum energy at the center turns at n=1 and 2 into a ring-like donut shape with an energy hole in the center. The azimuthally polarized TE₀₁ mode has originally (n=0) a ring-shaped intensity. At n=1, this configuration changes to have the maximum intensity in the center. At n=2, it becomes annular again. In the process, the spherical phase front of the beam of the linearly polarized EH₁₁ mode becomes spiral and have one singularity point on the axis, whereas the phase structure of the azimuthally polarized TE₀₁ mode gains a region with two phase singularity points off the axis.Conclusions. The results of the study can effectively facilitate information transfer in high-speed THz communication systems. They can provide a real platform to perform tasks related to tomography, exploring properties of materials, detecting astrophysical sources, which makes them very promising in modern technologies.Keywords: terahertz laser; waveguide resonator; spiral phase plate; vortex beams; polarization; radiation propagationManuscript submitted 11.12.2023Radio phys. radio astron. 2024, 29(2): 127-136REFERENCES1. Headland, D., Monnai, Y., Abbott, D., Christophe, F., and Withawat, W., 2018. Tutorial: Terahertz beamforming, from concepts to realizations. APL. Photonics, 3(5), pp. 051101. DOI: https://doi.org/10.1063/1.50110632. Forbes, A., 2023. Advances in orbital angular momentum lasers. J. Light. Technol., 41(7), pp. 2079—2086. DOI: https://doi.org/10.1109/JLT.2022.32205093. Wang, H., Song, Q., Cai, Y., Lin, Q., Lu, X., Shangguan, H., Ai, Y., and Xu, Y., 2020. Recent advances in generation of terahertz vortex beams and their applications. Chin. Phys. B., 29(9), pp. 097404. DOI: https://doi.org/10.1088/1674-1056/aba2df4. Petrov, N.V., Sokolenko, B., Kulya, M.S., Gorodetsky, A., and Chernykh, A.V., 2022. Design of broadband terahertz vector and vortex beams: I. Review of materials and components. Light: Adv. Manuf., 3(4), pp. 640—652. DOI: https://doi.org/10.37188/lam.2022.0435. Nagatsuma, T., Ducournau, G., and Renaud, C.C., 2016. Advances in terahertz communications accelerated by photonics. Nat. Photonics., 10(6), pp. 371—379. DOI: https://doi.org/10.1038/nphoton.2016.65 6. Chen, S., C., Feng, Z., Li, J., Tan, W., Du, L., H., Cai, J., and Zhu, L.G., 2020. Ghost spintronic THz-emitter-array microscope. Light Sci. Appl., 9(1), 99. DOI: https://doi.org/10.1038/s41377-020-0338-47. Nobahar, D., Khorram, S., 2022. Terahertz vortex beam propagation through a magnetized plasma-ferrite structure. Opt. Laser Technol., 146, 107522. DOI: https://doi.org/10.1016/j.optlastec.2021.1075228. Hibberd, M.T., Healy, A.L., Lake, D.S., Georgiadis, V., Smith, E.J., Finlay, O.J., and Jamison, S.P, 2019. Acceleration of relativistic beams using laser generated terahertz pulses. Nat. Photonics, 14(12), pp. 755—759. DOI: https://doi.org/10.1038/s41566-020-0674-19. Klug, A., Nape, I., and Forbes, A., 2021. The orbital angular momentum of a turbulent atmosphere and its impact on propagating structured light fields. New J. Phys., 23(9), 093012. DOI: https://doi.org/10.1088/1367-2630/ac1fca10. Pinnock, S.W., Roh, S., Biesner, T., Pronin, A.V., and Dressel, M., 2022. Generation of THz vortex beams and interferometric determination of their topological charge. IEEETrans. Terahertz Sci. Technol., 13(1), pp. 44—49. DOI: https://doi.org/10.1109/TTHZ.2022.322136911. Rubano, A., Cardano, F., Piccirillo, B., and Marrucci, L., 2019. Q-plate technology: a progress review [Invited]. J. Opt. Soc. Am. B., 36(5), pp. D70—D87. DOI: https://doi.org/10.1364/JOSAB.36.000D7012. Imai, R., Kanda, N., Higuchi, T., Konishi, K., and Kuwata-Gonokami, M., 2014. Generation of broadband terahertz vortex beams. Opt. Lett., 39(13), pp. 3714—3717. DOI: https://doi.org/10.1364/OL.39.00371413. Yang, Y., Ye, X., Niu, L., Wang, K., Yang, Z., and Liu, J., 2020. Generating terahertz perfect optical vortex beams by diffractive elements. Opt. Express, 28(2), pp. 1417—1425. DOI: https://doi.org/10.1364/OE.38007614. Zhang, K., Wang, Y., Burokur, S.N., and Wu, Q., 2022. Generating dual-polarized vortex beam by detour phase: from phase gradient metasurfaces to metagratings. IEEE Trans. Microw. Theory Techn., 70(1), pp. 200—209. DOI: https://doi.org/10.1109/TMTT.2021.307525115. Zhang, X.D., Su, Y.H., Ni, J.C., Wang, Z.Y., Wang, Y.L., Wang, C.W., and Chu, J.R., 2017. Optical superimposed vortex beams generated by integrated holographic plates with blazed grating. Appl. Phys. Lett., 111(6), 061901. DOI: https://doi.org/10.1063/1.499759016. Ge, S.J., Shen, Z.X., Chen, P., Liang, X., Wang, X.K., Hu, W., and Lu, Y.Q., 2017. Generating, separating and polarizing terahertz vortex beams via liquid crystals with gradient-rotation directors. Crystals, 7(10), 314. DOI: https://doi.org/10.3390/cryst710031417. Guan, S., Cheng, J., and Chang, S., 2022. Recent progress of terahertz spatial light modulators: materials, principles and applications. Micromachines, 13(10), 1637. DOI: https://doi.org/10.3390/mi1310163718. Al Dhaybi, A., Degert, J., Brasselet, E., Abraham, E., and Freysz, E.A., 2019. Terahertz vortex beam generation by infrared vector beam rectification. J. Opt. Soc. Am. B., 36(1), pp. 12—18. DOI: https://doi.org/10.1364/JOSAB.36.00001219. Miyamoto, K., Sano, K., Miyakawa, T., Niinomi, H., Toyoda, K., Vallés, A., and Omatsu, T., 2019. Generation of high-quality terahertz OAM mode based on soft-aperture difference frequency generation. Opt. Express, 27(22), pp. 31840—31849. DOI: https://doi.org/10.1364/OE.27.03184020. Sobhani, H., and Dadar, E., 2019. Terahertz vortex generation methods in rippled and vortex plasmas. J. Opt. Soc. Am. A., 36(7), pp. 1187—1196. DOI: https://doi.org/10.1364/JOSAA.36.00118721. Chevalier, P., Amirzhan, A., Wang, F., Piccardo, M., Johnson, S.G., Capasso, F., and Everitt, H.O., 2019. Widely tunable compact terahertz gas laser. Science, 366(6467), pp. 856—860. DOI: https://doi.org/10.1126/science.aay868322. Farhoomand, J., and Pickett, H.M., 1987. Stable 1.25 watts CW far infrared laser radiation at the 119 μm methanol line. Int. J. Infrared Millim. Waves, 8(5), pp 41—447. DOI: https://doi.org/10.1007/BF0101325723. Marcatilі, E.A.J., and Schmeltzer, R.A., 1964, Hollow metallic and dielectric waveguides for long distance optical transmission and lasers. Bell Syst. Tech. J., 43(4), pp. 1783—1809. DOI: https://doi.org/10.1002/j.1538-7305.1964.tb04108.x24. Beijersbergen, M.W., Coerwinkel, R.P.C., Kristensen, M., and Woerdman, J.P., 1994. Helical-wavefront laser beams produced with a spiral phase plate. Opt. Commun., 112(5—6), pp. 321—327. DOI: https://doi.org/10.1016/0030-4018(94)90638-625. Kotlyar, V.V., and Kovalev, A.A., 2010. Nonparaxial propagation of a Gaussian optical vortex with initial radial polarization. J. Opt. Soc. Am. A., 27(3), pp. 372—380. DOI: https://doi.org/10.1364/JOSAA.27.00037226. Gu, B., and Cui, Y., 2012. Nonparaxial and paraxial focusing of azimuthal-variant vector beams. Opt. Express, 20(16), pp. 17684— 17694. DOI: https://doi.org/10.1364/OE.20.01768427. Zhang, Y., Wang, L., and Zheng, C., 2005. Vector propagation of radially polarized Gaussian beams diffracted by an axicon. J. Opt. Soc. Am. A., 22(11), pp. 2542—2546. DOI: https://doi.org/10.1364/JOSAA.22.00254228. Lu, B., and Duan, K., 2003. Nonparaxial propagation of vectorial Gaussian beams diffracted at a circular aperture. Opt. Lett., 28(24), pp. 2440—2442. DOI: https://doi.org/10.1364/OL.28.00244029. Jia, X., Wang, Y., and Li, B., 2010. Nonparaxial analyses of radially polarized beams diffracted at a circular aperture. Opt. Express, 18(7), pp. 7064—7075. DOI: https://doi.org/10.1364/OE.18.00706430. Cui, X., Wang, C., and Jia, X., 2019. Nonparaxial propagation of vector vortex beams diffracted by a circular aperture. J. Opt. Soc. Am. A, 36(1), pp. 115—123. DOI: https://doi.org/10.1364/JOSAA.36.00011531. Nye, J.F., and Berry, M.V., 1974. Dislocations in wave trains. Proc. R. Soc. London. Ser. A., 336(1605), pp. 165—190. DOI: https://doi.org/10.1098/rspa.1974.001232. Gurin, O.V., Degtyarev, A.V., Dubinin, N.N., Legenkiy, M.N., Maslov, V.A., Muntean, K.I., Ryabykh, V.N., and Senyuta, V.S., 2021. Formation of beams with nonuniform polarisation of radiation in a cw waveguide terahertz laser. Quantum Electron., 51(4), pp. 338—342. DOI: https://doi.org/10.1070/QEL1751133. Gurin, O.V., Degtyarev, А.V., Dubinin, M.M., Maslov, V.A., Muntean, K.I., Ryabykh, V.N., and Senyuta, V.S., 2020. Focusing of modes with an inhomogeneous spatial polarization of the dielectric resonator of a terahertz laser. Telecommunications and Radio Engineering, 79(2), pp. 105—116. DOI: https://doi.org/10.1615/TelecomRadEng.v79.i2.3034. Guo, J., Zheng, S., Zhou, K., and Feng, G., 2021. Measurement of real phase distribution of a vortex beam propagating in free space based on an improved heterodyne interferometer. Appl. Phys. Lett., 119(2), 023504. DOI: https://doi.org/10.1063/5.0054755
publisher Видавничий дім «Академперіодика»
publishDate 2024
url http://rpra-journal.org.ua/index.php/ra/article/view/1442
work_keys_str_mv AT degtyarevav freespacepropagationofterahertzlaservortexbeams
AT dubininmm freespacepropagationofterahertzlaservortexbeams
AT maslovva freespacepropagationofterahertzlaservortexbeams
AT munteanki freespacepropagationofterahertzlaservortexbeams
AT svistunovoo freespacepropagationofterahertzlaservortexbeams
AT degtyarevav poširennâteragercovihvihrovihlazernihpučkívuvílʹnomuprostorí
AT dubininmm poširennâteragercovihvihrovihlazernihpučkívuvílʹnomuprostorí
AT maslovva poširennâteragercovihvihrovihlazernihpučkívuvílʹnomuprostorí
AT munteanki poširennâteragercovihvihrovihlazernihpučkívuvílʹnomuprostorí
AT svistunovoo poširennâteragercovihvihrovihlazernihpučkívuvílʹnomuprostorí
first_indexed 2025-12-02T15:27:24Z
last_indexed 2025-12-02T15:27:24Z
_version_ 1851757479415775232
spelling rpra-journalorgua-article-14422024-07-01T12:16:48Z FREE-SPACE PROPAGATION OF TERAHERTZ LASER VORTEX BEAMS ПОШИРЕННЯ ТЕРАГЕРЦОВИХ ВИХРОВИХ ЛАЗЕРНИХ ПУЧКІВ У ВІЛЬНОМУ ПРОСТОРІ Degtyarev, A. V. Dubinin, M. M. Maslov, V. A. Muntean, K. I. Svistunov, O. O. terahertz laser; waveguide resonator; spiral phase plate; vortex beams; polarization; radiation propagation терагерцовий лазер; хвилевідний резонатор; спіральна фазова пластинка; вихрові пучки; поляризація; поширення випромінювання Subject and Purpose. Currently, numerous ideas and different methods have been in growth for generating vortex beams — areas of the circular motion of the electromagnetic wave energy flow around the so-called phase singularity points caused by a violation of the wave front topological structure. The purpose of this work is to obtain analytical expressions describing the nonparaxial diffraction of wave modes of the waveguide resonator of a terahertz laser during the wave mode interaction with a spiral phase plate. The resulting vortex beams are examined for their physical features in free space propagation.Methods and Methodology. The Rayleigh-Sommerfeld vector theory is adopted to consider the propagation of vortex laser beams generated by wave modes of the quasi-optical waveguide cavity when interacting with a spiral phase plate in different diffraction zones.Results. For the first time, analytical expressions have been obtained to describe the nonparaxial diffraction of wave modes of the waveguide resonator of a terahertz laser, when resonator modes interact with a spiral phase plate at different topological charges, n. The physical features of the resulting vortex beams were studied in their free space propagation. It has been shown that a spiral phase plate modifies the structure of the linearly polarized EH₁₁ mode so that the original (n=0) intensity profile with the maximum energy at the center turns at n=1 and 2 into a ring-like donut shape with an energy hole in the center. The azimuthally polarized TE₀₁ mode has originally (n=0) a ring-shaped intensity. At n=1, this configuration changes to have the maximum intensity in the center. At n=2, it becomes annular again. In the process, the spherical phase front of the beam of the linearly polarized EH₁₁ mode becomes spiral and have one singularity point on the axis, whereas the phase structure of the azimuthally polarized TE₀₁ mode gains a region with two phase singularity points off the axis.Conclusions. The results of the study can effectively facilitate information transfer in high-speed THz communication systems. They can provide a real platform to perform tasks related to tomography, exploring properties of materials, detecting astrophysical sources, which makes them very promising in modern technologies.Keywords: terahertz laser; waveguide resonator; spiral phase plate; vortex beams; polarization; radiation propagationManuscript submitted 11.12.2023Radio phys. radio astron. 2024, 29(2): 127-136REFERENCES1. Headland, D., Monnai, Y., Abbott, D., Christophe, F., and Withawat, W., 2018. Tutorial: Terahertz beamforming, from concepts to realizations. APL. Photonics, 3(5), pp. 051101. DOI: https://doi.org/10.1063/1.50110632. Forbes, A., 2023. Advances in orbital angular momentum lasers. J. Light. Technol., 41(7), pp. 2079—2086. DOI: https://doi.org/10.1109/JLT.2022.32205093. Wang, H., Song, Q., Cai, Y., Lin, Q., Lu, X., Shangguan, H., Ai, Y., and Xu, Y., 2020. Recent advances in generation of terahertz vortex beams and their applications. Chin. Phys. B., 29(9), pp. 097404. DOI: https://doi.org/10.1088/1674-1056/aba2df4. Petrov, N.V., Sokolenko, B., Kulya, M.S., Gorodetsky, A., and Chernykh, A.V., 2022. Design of broadband terahertz vector and vortex beams: I. Review of materials and components. Light: Adv. Manuf., 3(4), pp. 640—652. DOI: https://doi.org/10.37188/lam.2022.0435. Nagatsuma, T., Ducournau, G., and Renaud, C.C., 2016. Advances in terahertz communications accelerated by photonics. Nat. Photonics., 10(6), pp. 371—379. DOI: https://doi.org/10.1038/nphoton.2016.65 6. Chen, S., C., Feng, Z., Li, J., Tan, W., Du, L., H., Cai, J., and Zhu, L.G., 2020. Ghost spintronic THz-emitter-array microscope. Light Sci. Appl., 9(1), 99. DOI: https://doi.org/10.1038/s41377-020-0338-47. Nobahar, D., Khorram, S., 2022. Terahertz vortex beam propagation through a magnetized plasma-ferrite structure. Opt. Laser Technol., 146, 107522. DOI: https://doi.org/10.1016/j.optlastec.2021.1075228. Hibberd, M.T., Healy, A.L., Lake, D.S., Georgiadis, V., Smith, E.J., Finlay, O.J., and Jamison, S.P, 2019. Acceleration of relativistic beams using laser generated terahertz pulses. Nat. Photonics, 14(12), pp. 755—759. DOI: https://doi.org/10.1038/s41566-020-0674-19. Klug, A., Nape, I., and Forbes, A., 2021. The orbital angular momentum of a turbulent atmosphere and its impact on propagating structured light fields. New J. Phys., 23(9), 093012. DOI: https://doi.org/10.1088/1367-2630/ac1fca10. Pinnock, S.W., Roh, S., Biesner, T., Pronin, A.V., and Dressel, M., 2022. Generation of THz vortex beams and interferometric determination of their topological charge. IEEETrans. Terahertz Sci. Technol., 13(1), pp. 44—49. DOI: https://doi.org/10.1109/TTHZ.2022.322136911. Rubano, A., Cardano, F., Piccirillo, B., and Marrucci, L., 2019. Q-plate technology: a progress review [Invited]. J. Opt. Soc. Am. B., 36(5), pp. D70—D87. DOI: https://doi.org/10.1364/JOSAB.36.000D7012. Imai, R., Kanda, N., Higuchi, T., Konishi, K., and Kuwata-Gonokami, M., 2014. Generation of broadband terahertz vortex beams. Opt. Lett., 39(13), pp. 3714—3717. DOI: https://doi.org/10.1364/OL.39.00371413. Yang, Y., Ye, X., Niu, L., Wang, K., Yang, Z., and Liu, J., 2020. Generating terahertz perfect optical vortex beams by diffractive elements. Opt. Express, 28(2), pp. 1417—1425. DOI: https://doi.org/10.1364/OE.38007614. Zhang, K., Wang, Y., Burokur, S.N., and Wu, Q., 2022. Generating dual-polarized vortex beam by detour phase: from phase gradient metasurfaces to metagratings. IEEE Trans. Microw. Theory Techn., 70(1), pp. 200—209. DOI: https://doi.org/10.1109/TMTT.2021.307525115. Zhang, X.D., Su, Y.H., Ni, J.C., Wang, Z.Y., Wang, Y.L., Wang, C.W., and Chu, J.R., 2017. Optical superimposed vortex beams generated by integrated holographic plates with blazed grating. Appl. Phys. Lett., 111(6), 061901. DOI: https://doi.org/10.1063/1.499759016. Ge, S.J., Shen, Z.X., Chen, P., Liang, X., Wang, X.K., Hu, W., and Lu, Y.Q., 2017. Generating, separating and polarizing terahertz vortex beams via liquid crystals with gradient-rotation directors. Crystals, 7(10), 314. DOI: https://doi.org/10.3390/cryst710031417. Guan, S., Cheng, J., and Chang, S., 2022. Recent progress of terahertz spatial light modulators: materials, principles and applications. Micromachines, 13(10), 1637. DOI: https://doi.org/10.3390/mi1310163718. Al Dhaybi, A., Degert, J., Brasselet, E., Abraham, E., and Freysz, E.A., 2019. Terahertz vortex beam generation by infrared vector beam rectification. J. Opt. Soc. Am. B., 36(1), pp. 12—18. DOI: https://doi.org/10.1364/JOSAB.36.00001219. Miyamoto, K., Sano, K., Miyakawa, T., Niinomi, H., Toyoda, K., Vallés, A., and Omatsu, T., 2019. Generation of high-quality terahertz OAM mode based on soft-aperture difference frequency generation. Opt. Express, 27(22), pp. 31840—31849. DOI: https://doi.org/10.1364/OE.27.03184020. Sobhani, H., and Dadar, E., 2019. Terahertz vortex generation methods in rippled and vortex plasmas. J. Opt. Soc. Am. A., 36(7), pp. 1187—1196. DOI: https://doi.org/10.1364/JOSAA.36.00118721. Chevalier, P., Amirzhan, A., Wang, F., Piccardo, M., Johnson, S.G., Capasso, F., and Everitt, H.O., 2019. Widely tunable compact terahertz gas laser. Science, 366(6467), pp. 856—860. DOI: https://doi.org/10.1126/science.aay868322. Farhoomand, J., and Pickett, H.M., 1987. Stable 1.25 watts CW far infrared laser radiation at the 119 μm methanol line. Int. J. Infrared Millim. Waves, 8(5), pp 41—447. DOI: https://doi.org/10.1007/BF0101325723. Marcatilі, E.A.J., and Schmeltzer, R.A., 1964, Hollow metallic and dielectric waveguides for long distance optical transmission and lasers. Bell Syst. Tech. J., 43(4), pp. 1783—1809. DOI: https://doi.org/10.1002/j.1538-7305.1964.tb04108.x24. Beijersbergen, M.W., Coerwinkel, R.P.C., Kristensen, M., and Woerdman, J.P., 1994. Helical-wavefront laser beams produced with a spiral phase plate. Opt. Commun., 112(5—6), pp. 321—327. DOI: https://doi.org/10.1016/0030-4018(94)90638-625. Kotlyar, V.V., and Kovalev, A.A., 2010. Nonparaxial propagation of a Gaussian optical vortex with initial radial polarization. J. Opt. Soc. Am. A., 27(3), pp. 372—380. DOI: https://doi.org/10.1364/JOSAA.27.00037226. Gu, B., and Cui, Y., 2012. Nonparaxial and paraxial focusing of azimuthal-variant vector beams. Opt. Express, 20(16), pp. 17684— 17694. DOI: https://doi.org/10.1364/OE.20.01768427. Zhang, Y., Wang, L., and Zheng, C., 2005. Vector propagation of radially polarized Gaussian beams diffracted by an axicon. J. Opt. Soc. Am. A., 22(11), pp. 2542—2546. DOI: https://doi.org/10.1364/JOSAA.22.00254228. Lu, B., and Duan, K., 2003. Nonparaxial propagation of vectorial Gaussian beams diffracted at a circular aperture. Opt. Lett., 28(24), pp. 2440—2442. DOI: https://doi.org/10.1364/OL.28.00244029. Jia, X., Wang, Y., and Li, B., 2010. Nonparaxial analyses of radially polarized beams diffracted at a circular aperture. Opt. Express, 18(7), pp. 7064—7075. DOI: https://doi.org/10.1364/OE.18.00706430. Cui, X., Wang, C., and Jia, X., 2019. Nonparaxial propagation of vector vortex beams diffracted by a circular aperture. J. Opt. Soc. Am. A, 36(1), pp. 115—123. DOI: https://doi.org/10.1364/JOSAA.36.00011531. Nye, J.F., and Berry, M.V., 1974. Dislocations in wave trains. Proc. R. Soc. London. Ser. A., 336(1605), pp. 165—190. DOI: https://doi.org/10.1098/rspa.1974.001232. Gurin, O.V., Degtyarev, A.V., Dubinin, N.N., Legenkiy, M.N., Maslov, V.A., Muntean, K.I., Ryabykh, V.N., and Senyuta, V.S., 2021. Formation of beams with nonuniform polarisation of radiation in a cw waveguide terahertz laser. Quantum Electron., 51(4), pp. 338—342. DOI: https://doi.org/10.1070/QEL1751133. Gurin, O.V., Degtyarev, А.V., Dubinin, M.M., Maslov, V.A., Muntean, K.I., Ryabykh, V.N., and Senyuta, V.S., 2020. Focusing of modes with an inhomogeneous spatial polarization of the dielectric resonator of a terahertz laser. Telecommunications and Radio Engineering, 79(2), pp. 105—116. DOI: https://doi.org/10.1615/TelecomRadEng.v79.i2.3034. Guo, J., Zheng, S., Zhou, K., and Feng, G., 2021. Measurement of real phase distribution of a vortex beam propagating in free space based on an improved heterodyne interferometer. Appl. Phys. Lett., 119(2), 023504. DOI: https://doi.org/10.1063/5.0054755 Предмет і мета роботи. На цей час набули поширення ідеї розробки методів формування вихрових пучків — областей кругового руху потоку енергії в електромагнітній хвилі навколо так званих точок фазових сингулярностей, обумовле- них порушенням топологічної структури хвильового фронту. Мета цієї роботи — отримання аналітичних виразів для опису непараксіальної дифракції мод діелектричного хвилевідного резонатора терагерцового лазера у процесі їх взаємодії зі спіральною фазовою пластинкою та вивчення фізичних особливостей отриманих вихрових пучків при їх поширенні у вільному просторі.Методи та методологія. Для вивчення поширення вихрових лазерних пучків, збуджуваних модами діелектричного хвилевідного квазіоптичного резонатора при їх взаємодії зі спіральною фазовою пластинкою в різних зонах дифракції, була застосована векторна теорія Релея–Зоммерфельда.Результати. Уперше отримано аналітичні вирази для опису непараксіальної дифракції мод діелектричного хвилевідного резонатора терагерцового лазера у процесі їх взаємодії зі спіральною фазовою пластинкою з довільним топологічним зарядом (n). Вивчені фізичні особливості отриманих вихрових пучків при їх поширенні у вільному просторі. Показано, що спіральна фазова пластина для лінійно поляризованої ЕH₁₁-моди з структури із максимумом інтенсивності в центрі (n=0) формує кільцеву (n=1, 2) структуру. Для азимутально поляризованої TE₀₁-моди кільцева (n=0) структура перетворюється на структуру із максимумом інтенсивності в центрі (n=1), а надалі знову в кільцеву (n=2). За таких умов фазовий фронт променя лінійно поляризованої ЕH₁₁-моди перетворюється зі сферичного в спіральний з однією точкою сингулярності на осі, тоді як для фазової структури азимутально поляризованої TE₀₁-моди з’являється область з двома точками фазової сингулярності поза віссю.Висновки. Результати дослідження можуть забезпечити ефективний метод передачі інформації у високошвидкісних системах ТГц-зв’язку та виконання завдань, пов’язаних з томографією, із дослідженням властивостей матеріалів, знаходженням астрофізичних джерел, що робить їх дуже перспективними в сучасних технологіях.Ключові  слова: терагерцовий  лазер;  хвилевідний  резонатор;  спіральна  фазова  пластинка;  вихрові  пучки;  поляризація; поширення випромінюванняСтаття надійшла до редакції 11.12.2023Radio phys. radio astron. 2024, 29(2): 127-136БІБЛІОГРАФІЧНИЙ СПИСОК    1. Headland D., Monnai Y., Abbott D., Christophe F., and Withawat W. Tutorial: Terahertz beamforming, from concepts to realizations. APL. Photonics. 2018. Vol. 3, Iss. 5. P. 051101. DOI: 10.1063/1.5011063    2. Forbes A. Advances in orbital angular momentum lasers. J. Light. Technol. 2023. Vol. 41, Iss. 7. P. 2079—2086. DOI: 10.1109/ JLT.2022.3220509.    3. Wang H., Song Q., Cai Y., Lin Q., Lu X., Shangguan H., Ai Y., and Xu Y. Recent advances in generation of terahertz vortex beams and their applications. Chin. Phys. B. 2020. Vol. 29, Iss. 9. P. 097404. DOI: 10.1088/1674-1056/aba2df    4. Petrov N.V., Sokolenko B., Kulya M.S., Gorodetsky A., and Chernykh A.V. Design of broadband terahertz vector and vortex beams: I. Review of materials and components. Light: Adv. Manuf. 2022. Vol. 3, Iss. 4. P. 640—652. DOI: 10.37188/lam.2022.043    5. Nagatsuma T., Ducournau G., and Renaud C.C. Advances in terahertz communications accelerated by photonics. Nat. Photonics.2016. Vol. 10, Iss. 6. P. 371—379. DOI: 10.1038/nphoton.2016.65    6. Chen S.C., Feng, Z., Li J., Tan W., Du L.H., Cai J., and Zhu L.G. Ghost spintronic THz-emitter-array microscope. Light Sci. Appl. 2020. Vol. 9, Iss. 1. P. 99. DOI: 10.1038/s41377-020-0338-4    7. Nobahar D., Khorram S. Terahertz vortex beam propagation through a magnetized plasma-ferrite structure. Opt. Laser Technol.2022. Vol. 146. P. 107522. DOI: 10.1016/j.optlastec.2021.107522    8. Hibberd M.T., Healy A.L., Lake D.S., Georgiadis V., Smith E.J., Finlay O. J., and Jamison S.P. Acceleration of relativistic beams using laser generated terahertz pulses. Nat. Photonics. 2019. Vol. 14, Iss. 12. P. 755—759. DOI: 10.1038/s41566-020-0674-1    9. Klug A., Nape I., and Forbes A. The orbital angular momentum of a turbulent atmosphere and its impact on propagating structured light fields. New J. Phys. 2021. Vol. 23, Iss. 9. P. 093012. DOI: 10.1088/1367-2630/ac1fca    10. Pinnock S.W., Roh S., Biesner T., Pronin A.V., and Dressel M. Generation of THz vortex beams and interferometric determination of their topological charge. IEEE Trans. Terahertz Sci. Technol. 2022. Vol. 13, Iss. 1. P. 44—49. DOI: 10.1109/TTHZ.2022.3221369    11. Rubano A., Cardano F., Piccirillo B., and Marrucci L. 2019. Q-plate technology: a progress review [Invited]. J. Opt. Soc. Am. B.2019. Vol. 36, Iss. 5. P. D70—D87. DOI: 10.1364/JOSAB.36.000D70    12. Imai R., Kanda N., Higuchi T., Konishi K., and Kuwata-Gonokami M. Generation of broadband terahertz vortex beams. Opt. Lett.2014. Vol. 39, Iss. 13. P. 3714—3717. DOI: 10.1364/OL.39.003714    13. Yang Y., Ye X., Niu L., Wang K., Yang Z., and Liu J. Generating terahertz perfect optical vortex beams by diffractive elements. Opt. Express. 2020. Vol. 28, Iss. 2. P. 1417—1425. DOI: 10.1364/OE.380076    14. Zhang K., Wang Y., Burokur S.N., and Wu Q. Generating dual-polarized vortex beam  by  detour  phase:  from  phase gradient metasurfaces to metagratings. IEEE Trans. Microw. Theory Techn. 2022. Vol. 70, Iss. 1. P. 200—209. DOI: 10.1109/ TMTT.2021.3075251    15. Zhang X.D., Su Y.H., Ni J.C., Wang Z.Y., Wang Y.L., Wang C.W., and Chu, J.R. Optical superimposed vortex beams generated by integrated holographic plates with blazed grating. Appl. Phys. Lett. 2017. Vol. 111, Iss. 6. P. 061901. DOI: 10.1063/1.4997590    16. Ge S.J., Shen Z.X., Chen P., Liang X., Wang X.K., Hu W., and Lu Y.Q. Generating, separating and polarizing terahertz vortex beams via liquid crystals with gradient-rotation directors. Crystals. 2017. Vol. 7, Iss. 10. 314. DOI: 10.3390/cryst7100314    17. Guan S., Cheng J., and Chang S. Recent progress of terahertz spatial light modulators: materials, principles and applications.Micromachines. 2022. Vol. 13, Iss. 10. 1637. DOI: 10.3390/mi13101637    18. Al Dhaybi A., Degert J., Brasselet E., Abraham E., and Freysz E.A. Terahertz vortex beam generation by infrared vector beam rectification. J. Opt. Soc. Am. B. 2019. Vol. 36, Iss. 1. P. 12—18. DOI: 10.1364/JOSAB.36.000012    19. Miyamoto K., Sano K., Miyakawa T., Niinomi H., Toyoda K., Vallés A., and Omatsu T. Generation of high-quality terahertz OAM mode based on soft-aperture difference frequency generation. Opt. Express. 2019. Vol. 27, Iss. 22. P. 31840—31849. DOI: 10.1364/ OE.27.031840    20. Sobhani H., and Dadar E. Terahertz vortex generation methods in rippled and vortex plasmas. J. Opt. Soc. Am. A. 2019. Vol. 36, Iss. 7. P. 1187—1196. DOI: 10.1364/JOSAA.36.001187    21. Chevalier P., Amirzhan A., Wang F., Piccardo M., Johnson S.G., Capasso F., and Everitt H.O. Widely tunable compact terahertz gas laser. Science. 2019. Vol. 366, Iss. 6467. P. 856—860. DOI: 10.1126/science.aay8683    22. Farhoomand J., and Pickett H.M. Stable 1.25 watts CW far infrared laser radiation at the 119 μm methanol line. Int. J. Infrared Millim. Waves. 1987. Vol. 8, Iss. 5. P. 441—447. DOI: 10.1007/BF01013257    23. Marcatilі E.A.J., and Schmeltzer R.A. Hollow metallic and dielectric waveguides for long distance optical transmission and lasers.Bell Syst. Tech. J. 1964. Vol. 43, Iss. 4. P. 1783—1809. DOI: 10.1002/j.1538-7305.1964.tb04108.x    24. Beijersbergen M.W., Coerwinkel R.P.C., Kristensen M., and Woerdman J.P. Helical-wavefront laser beams produced with a spiral phase plate. Opt. Commun. 1994. Vol. 112, Iss. 5—6. P. 321—327. DOI: 10.1016/0030-4018(94)90638-6    25. Kotlyar V.V., and Kovalev A.A. Nonparaxial propagation of a Gaussian optical vortex with initial radial polarization, J. Opt. Soc. Am. A. 2010. Vol. 27, Iss. 3. P. 372—380. DOI: 10.1364/JOSAA.27.000372    26. Gu B., and Cui Y. Nonparaxial and paraxial focusing of azimuthal-variant vector beams. Opt. Express. 2012. Vol. 20, Iss. 16. P. 17684—17694. DOI: 10.1364/OE.20.017684    27. Zhang Y., Wang L., and Zheng C. Vector propagation of radially polarized Gaussian beams diffracted by an axicon. J. Opt. Soc. Am. A. 2005. Vol. 22, Iss. 11. P. 2542—2546. DOI: 10.1364/JOSAA.22.002542    28. Lu B., and Duan K., Nonparaxial propagation of vectorial Gaussian beams diffracted at a circular aperture. Opt. Lett. 2003. Vol. 28, Iss. 24. P. 2440—2442. DOI: 10.1364/OL.28.002440    29. Jia X., Wang Y., and Li B., Nonparaxial analyses of radially polarized beams diffracted at a circular aperture, Opt. Express. 2010. Vol. 18, Iss. 7. P. 7064—7075. DOI: 10.1364/OE.18.007064    30. Cui X., Wang C., and Jia X., Nonparaxial propagation of vector vortex beams diffracted by a circular aperture, J. Opt. Soc. Am. A. 2019. Vol. 36, Iss. 1. P. 115—123. DOI: 10.1364/JOSAA.36.000115    31. Nye J.F., and Berry M.V. Dislocations in wave trains. Proc. R. Soc. London. Ser. A. 1974. Vol. 336, Iss. 1605. P. 165—190. DOI: 10.1098/rspa.1974.0012    32. Gurin O.V., Degtyarev A.V., Dubinin N.N., Legenkiy M.N., Maslov V.A., Muntean K.I., Ryabykh V.N., and Senyuta V.S. Formation of beams with nonuniform polarisation of radiation in a cw waveguide terahertz laser. Quantum Electron. 2021. Vol. 51, Iss. 4. P. 338—342. DOI: 10.1070/QEL17511    33. Gurin O.V., Degtyarev А.V., Dubinin M.M., Maslov V.A., Muntean K.I., Ryabykh V.N., and Senyuta V.S. Focusing of modes with an inhomogeneous spatial polarization of the dielectric resonator of a terahertz laser. Telecommunications and Radio Engineering. 2020. Vol. 79, Iss. 2. P. 105—116. DOI: 10.1615/TelecomRadEng.v79.i2.30    34. Guo J., Zheng S., Zhou K., and Feng G. Measurement of real phase distribution of a vortex beam propagating in free space based on an improved heterodyne interferometer. Appl. Phys. Lett. 2021. Vol. 119, Iss. 2. 023504. DOI: 10.1063/5.0054755 Видавничий дім «Академперіодика» 2024-06-24 Article Article application/pdf http://rpra-journal.org.ua/index.php/ra/article/view/1442 10.15407/rpra29.02.127 РАДИОФИЗИКА И РАДИОАСТРОНОМИЯ; Vol 29, No 2 (2024); 127 RADIO PHYSICS AND RADIO ASTRONOMY; Vol 29, No 2 (2024); 127 РАДІОФІЗИКА І РАДІОАСТРОНОМІЯ; Vol 29, No 2 (2024); 127 2415-7007 1027-9636 10.15407/rpra29.02 uk http://rpra-journal.org.ua/index.php/ra/article/view/1442/pdf Copyright (c) 2024 RADIO PHYSICS AND RADIO ASTRONOMY