{"id":6920,"date":"2015-12-07T06:54:45","date_gmt":"2015-12-07T06:54:45","guid":{"rendered":"http:\/\/revoscience.com\/en\/?p=6920"},"modified":"2015-12-07T06:54:45","modified_gmt":"2015-12-07T06:54:45","slug":"steering-the-flow-of-light","status":"publish","type":"post","link":"https:\/\/www.revoscience.com\/en\/steering-the-flow-of-light\/","title":{"rendered":"Steering the flow of light"},"content":{"rendered":"<p style=\"text-align: justify;\"><span style=\"color: #000000;\"><em><strong style=\"color: #000000;\">Tiny particles with varied shapes scatter light in useful and unusual ways.<\/strong><\/em><\/span><\/p>\n<figure id=\"attachment_6921\" aria-describedby=\"caption-attachment-6921\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"http:\/\/revoscience.com\/en\/wp-content\/uploads\/2015\/12\/3182.jpg\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-6921\" src=\"http:\/\/revoscience.com\/en\/wp-content\/uploads\/2015\/12\/3182.jpg\" alt=\"The strength and direction of light scattering can be controlled by carefully selecting a nanostructure\u2019s shape and refractive index. \u00a9 A*STAR Data Storage Institute\" width=\"300\" height=\"259\" title=\"\"><\/a><figcaption id=\"caption-attachment-6921\" class=\"wp-caption-text\">The strength and direction of light scattering can be controlled by carefully selecting a nanostructure\u2019s shape and refractive index. \u00a9 A*STAR Data Storage Institute<\/figcaption><\/figure>\n<p style=\"text-align: justify;\"><span style=\"font-weight: normal; color: #000000;\">A study into the way nanoparticles scatter light could lead to simpler and smaller optical nanoantennas with improved directivity and efficiency \u2014 crucial components for the next generation of advanced photonic devices.\u00a0<\/span><br style=\"font-weight: normal; color: #000000;\" \/><br style=\"font-weight: normal; color: #000000;\" \/><span style=\"font-weight: normal; color: #000000;\">Boris Luk\u2019yanchuk and co-workers from the Agency for Science, Technology and Research (A*STAR) Data Storage Institute, Singapore, together with a collaborator in St. Petersburg University, Russia, undertook a detailed numerical investigation of the light scattering characteristics of dielectric nanoparticles of different shapes with high refractive indexes (larger than 2). They focused particularly on nanoscale spheres and spheroids.\u00a0<\/span><br style=\"font-weight: normal; color: #000000;\" \/><br style=\"font-weight: normal; color: #000000;\" \/><span style=\"font-weight: normal; color: #000000;\">By carefully selecting the nanoparticle\u2019s shape and refractive index, the team discovered they could use the interference between the particle\u2019s electric and magnetic dipole resonances to control and optimize the strength and direction of its light scattering.\u00a0<\/span><br style=\"font-weight: normal; color: #000000;\" \/><br style=\"font-weight: normal; color: #000000;\" \/><span style=\"font-weight: normal; color: #000000;\">For example, they found that for a spheroid particle with a refractive index of 3.5, scattering in the forward direction can be maximized if the spheroid\u2019s major axis is just over twice the length of its minor axis.\u00a0<\/span><br style=\"font-weight: normal; color: #000000;\" \/><br style=\"font-weight: normal; color: #000000;\" \/><span style=\"font-weight: normal; color: #000000;\">Steering the flow of light by manipulating the nanoparticle\u2019s aspect ratio is potentially useful in many applications, for example to maximize the light captured by a solar cell or to make artificially-engineered metasurfaces that can cause light to flow in interesting and unusual ways.\u00a0<\/span><br style=\"font-weight: normal; color: #000000;\" \/><br style=\"font-weight: normal; color: #000000;\" \/><\/p>\n<p style=\"text-align: justify;\">[pullquote]By carefully selecting the nanoparticle\u2019s shape and refractive index, the team discovered they could use the interference between the particle\u2019s electric and magnetic dipole resonances to control and optimize the strength and direction of its light scattering.\u00a0[\/pullquote]<\/p>\n<p style=\"text-align: justify;\"><span style=\"font-weight: normal; color: #000000;\">\u201cDielectric particles with optimized shapes which behave as very efficient directional antennas can be used in sensing devices, transmission lines, metasurfaces with numerous uses and in many other devices such as negative refractive index lenses, optical cloaking devices or nanolasers,\u201d explained Luk\u2019yanchuk, the lead researcher in the study.\u00a0<\/span><br style=\"font-weight: normal; color: #000000;\" \/><br style=\"font-weight: normal; color: #000000;\" \/><span style=\"font-weight: normal; color: #000000;\">\u201cThe fascinating properties of dielectric materials with high refractive indexes are related to their ability to have both electric and magnetic dipoles. It makes it possible to produce different interference phenomena in their scattering, like Fano resonances for example. We are trying to use these effects to produce different types of nanoscale devices and metasurfaces.\u201d\u00a0<\/span><br style=\"font-weight: normal; color: #000000;\" \/><br style=\"font-weight: normal; color: #000000;\" \/><span style=\"font-weight: normal; color: #000000;\">According to Luk\u2019yanchuk, the physics of this scattering is valid and scalable across the electromagnetic spectrum and thus their approach could be applied not only at optical and infrared frequencies, but at microwave frequencies as well, provided that suitable transparent particles with a sufficiently high refractive index are used.\u00a0<\/span><br style=\"font-weight: normal; color: #000000;\" \/><br style=\"font-weight: normal; color: #000000;\" \/><span style=\"font-weight: normal; color: #000000;\">\u201cAt optical frequencies, for example, there are many suitable materials like titanium dioxide, silicon, germanium, gallium arsenide and other group IV and III-V semiconductors,\u201d commented Luk\u2019yanchuk. \u201cThe possible limitation would be frequencies higher than the visible range, like the ultraviolet, where no high-index transparent dielectrics are readily available.\u201d<\/span><br style=\"font-weight: normal; color: #000000;\" \/><br style=\"font-weight: normal; color: #000000;\" \/><span style=\"font-weight: normal; color: #000000;\">The A*STAR-affiliated researchers contributing to this research are from the Data Storage Institute.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>A study into the way nanoparticles scatter light could lead to simpler and smaller optical nanoantennas with improved directivity and efficiency \u2014 crucial components for the next generation of advanced photonic devices. <\/p>\n","protected":false},"author":6,"featured_media":6921,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17],"tags":[],"class_list":["post-6920","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research"],"featured_image_urls":{"full":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/12\/3182.jpg",300,259,false],"thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/12\/3182-150x150.jpg",150,150,true],"medium":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/12\/3182.jpg",300,259,false],"medium_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/12\/3182.jpg",300,259,false],"large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/12\/3182.jpg",300,259,false],"1536x1536":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/12\/3182.jpg",300,259,false],"2048x2048":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/12\/3182.jpg",300,259,false],"ultp_layout_landscape_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/12\/3182.jpg",300,259,false],"ultp_layout_landscape":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/12\/3182.jpg",300,259,false],"ultp_layout_portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/12\/3182.jpg",300,259,false],"ultp_layout_square":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/12\/3182.jpg",300,259,false],"newspaper-x-single-post":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/12\/3182.jpg",300,259,false],"newspaper-x-recent-post-big":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/12\/3182.jpg",300,259,false],"newspaper-x-recent-post-list-image":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/12\/3182.jpg",75,65,false],"web-stories-poster-portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/12\/3182.jpg",300,259,false],"web-stories-publisher-logo":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/12\/3182.jpg",96,83,false],"web-stories-thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/12\/3182.jpg",150,130,false]},"author_info":{"info":["Amrita Tuladhar"]},"category_info":"<a href=\"https:\/\/www.revoscience.com\/en\/category\/news\/research\/\" rel=\"category tag\">Research<\/a>","tag_info":"Research","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/6920","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/comments?post=6920"}],"version-history":[{"count":0,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/6920\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media\/6921"}],"wp:attachment":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media?parent=6920"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/categories?post=6920"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/tags?post=6920"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}