{"id":7886,"date":"2024-09-13T11:29:51","date_gmt":"2024-09-13T08:29:51","guid":{"rendered":"https:\/\/quantum-electronics.ru\/en\/?p=7886"},"modified":"2024-09-13T13:37:39","modified_gmt":"2024-09-13T10:37:39","slug":"single-mode-p2o5-f-sio2-optical-fibres-with-an-optimised-acoustic-profile-influence-of-the-optical-refractive-index-contrast-and-dopant-content-of-the-core-on-maximum-sbs-gain-suppres","status":"publish","type":"post","link":"https:\/\/quantum-electronics.ru\/en\/single-mode-p2o5-f-sio2-optical-fibres-with-an-optimised-acoustic-profile-influence-of-the-optical-refractive-index-contrast-and-dopant-content-of-the-core-on-maximum-sbs-gain-suppres\/","title":{"rendered":"Single-mode P2O5\u2013F\u2013SiO2 optical fibres with an optimised acoustic profile: Influence of the optical refractive index contrast and dopant content of the core on maximum SBS gain suppression"},"content":{"rendered":"<p>S. V. Tsvetkov, M. E. Likhachev<\/p>\n<ul>\n<li>Fiber Optics Research Center of the Russian Academy of Sciences<\/li>\n<\/ul>\n<div class=\"around-button\"><b>Abstract:<\/b> We consider optical fibres with a modified radial profile of the acoustic refractive index. The use of two-component doping of the core in a silica optical fibre makes it possible to simultaneously create different refractive index profiles for electrostriction-induced optical and hypersonic acoustic waves, which can be used to effectively reduce the stimulated Brillouin scattering (SBS) gain. The use of phosphorus oxide (P<sub>2<\/sub>O<sub>5<\/sub>) and fluorine (F) allows one, while maintaining the optical single-mode regime, to realise a high-contrast acoustic refractive index profile (ARIP), in which, under the condition of optimising its shape, a large number of guided acoustic modes can be effectively involved in SBS. It creates a wide multiband SBS gain spectrum and leads to a decrease in the absolute value of its maximum proportional to the number of these acoustic modes. In this paper, for such fibres with a step-index optical refractive index profile, we theoretically investigate a dependence of the absolute SBS gain maximum on the core\/cladding optical refractive index contrast \u0394<i>n<\/i> at the ARIP parameters providing a maximum possible decrease due to multimode acoustics. Real technological limitations on the maximum doping of silica glass simultaneously with P<sub>2<\/sub>O<sub>5<\/sub> and F (in particular, for the modified chemical method of vapour deposition, MCVD) are taken into account. An approximate analytical model of the optimal ARIP (and, accordingly, the radial distributions of P<sub>2<\/sub>O<sub>5<\/sub> and F concentrations) is also presented. The obtained results lead to a conclusion that the deepest SBS gain suppression (up to 15 dB) in P<sub>2<\/sub>O<sub>5<\/sub>\u2013F\u2013SiO<sub>2<\/sub> optical fibres can be achieved at \u0394<i>n<\/i> < 0.0045, while at 0.0045 < \u0394<i>n<\/i> < 0.0075 these limits are objectively limited to 6 dB, and at \u0394<i>n<\/i> > 0.0075 other glass compositions or methods must be used.<\/div>\n<div><\/div>\n<div class=\"around-button\"><b>Keywords:<\/b> <i>single-mode optical fibre, stimulated Brillouin scattering (SBS), acoustic refractive index profile, phosphorus\u2013fluorine\u2013silicate fibre, SBS gain.<\/i><\/div>\n<div class=\"around-button\"><b>Received:<\/b> 21.07.2022<\/div>\n","protected":false},"excerpt":{"rendered":"<p>S. V. Tsvetkov, M. E. Likhachev Fiber Optics Research Center of the Russian Academy of Sciences Abstract: We consider optical fibres with a modified radial profile of the acoustic refractive index. The use of two-component doping of the core in a silica optical fibre makes it possible to simultaneously create different refractive index profiles for\u2026 <span class=\"read-more\"><a href=\"https:\/\/quantum-electronics.ru\/en\/single-mode-p2o5-f-sio2-optical-fibres-with-an-optimised-acoustic-profile-influence-of-the-optical-refractive-index-contrast-and-dopant-content-of-the-core-on-maximum-sbs-gain-suppres\/\">Read More &raquo;<\/a><\/span><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-7886","post","type-post","status-publish","format-standard","hentry","category-stats"],"_links":{"self":[{"href":"https:\/\/quantum-electronics.ru\/en\/wp-json\/wp\/v2\/posts\/7886","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/quantum-electronics.ru\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/quantum-electronics.ru\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/quantum-electronics.ru\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/quantum-electronics.ru\/en\/wp-json\/wp\/v2\/comments?post=7886"}],"version-history":[{"count":0,"href":"https:\/\/quantum-electronics.ru\/en\/wp-json\/wp\/v2\/posts\/7886\/revisions"}],"wp:attachment":[{"href":"https:\/\/quantum-electronics.ru\/en\/wp-json\/wp\/v2\/media?parent=7886"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/quantum-electronics.ru\/en\/wp-json\/wp\/v2\/categories?post=7886"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/quantum-electronics.ru\/en\/wp-json\/wp\/v2\/tags?post=7886"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}