{"id":138997,"date":"2023-04-21T11:30:19","date_gmt":"2023-04-21T15:30:19","guid":{"rendered":"http:\/\/www.bu.edu\/eng\/?p=138997"},"modified":"2023-08-18T11:50:53","modified_gmt":"2023-08-18T15:50:53","slug":"the-skys-the-limit","status":"publish","type":"post","link":"https:\/\/www.bu.edu\/eng\/2023\/04\/21\/the-skys-the-limit\/","title":{"rendered":"The Sky&#8217;s the Limit"},"content":{"rendered":"<h3><strong>Ramachandran Team\u2019s Light Transmission Discovery Published by <em>Science<\/em><\/strong><\/h3>\n<p><strong>By A.J. Kleber<\/strong><\/p>\n<p>It\u2019s undeniable that the amount of data people are generating in digital spaces is constantly, exponentially growing. We tend to think of information as ephemeral, hovering insubstantially in \u201cthe cloud,\u201d but in reality there are physical limits to how our data is stored and transmitted, and this continual increase in content is beginning to pose a challenge to the optical fibers that form the infrastructure through which it travels.<\/p>\n<p>The information is sent in the form of beams of light, which can be maintained and relayed over globe-spanning distances using a phenomenon called \u201ctotal internal reflection,\u201d which allows light to bounce off the walls of an optical fiber \u201clight pipe\u201d with minimal loss. However, the capacity of a given optical fiber is limited\u2014a limit our expanding data generation threatens to exceed. Fresh solutions are needed, which is where Distinguished Professor of Engineering <a href=\"https:\/\/www.bu.edu\/eng\/profile\/siddharth-ramachandran\/\" target=\"_blank\" rel=\"noopener noreferrer\">Siddharth Ramachandran<\/a> (<a href=\"https:\/\/www.bu.edu\/eng\/ece\" target=\"_blank\" rel=\"noopener noreferrer\">ECE<\/a>, Physics, <a href=\"https:\/\/www.bu.edu\/eng\/mse\" target=\"_blank\" rel=\"noopener noreferrer\">MSE<\/a>) and ECE PhD candidate Zelin Ma come in.<\/p>\n<figure id=\"attachment_139002\" aria-describedby=\"caption-attachment-139002\" style=\"width: 268px\" class=\"wp-caption alignleft\"><img loading=\"lazy\" src=\"\/eng\/files\/2023\/04\/22-1332-ENGFACULTY-015-424x636.jpg\" alt=\"\" class=\"wp-image-139002 \" width=\"258\" height=\"387\" srcset=\"https:\/\/www.bu.edu\/eng\/files\/2023\/04\/22-1332-ENGFACULTY-015-424x636.jpg 424w, https:\/\/www.bu.edu\/eng\/files\/2023\/04\/22-1332-ENGFACULTY-015-683x1024.jpg 683w, https:\/\/www.bu.edu\/eng\/files\/2023\/04\/22-1332-ENGFACULTY-015-768x1151.jpg 768w, https:\/\/www.bu.edu\/eng\/files\/2023\/04\/22-1332-ENGFACULTY-015-1025x1536.jpg 1025w, https:\/\/www.bu.edu\/eng\/files\/2023\/04\/22-1332-ENGFACULTY-015-1366x2048.jpg 1366w, https:\/\/www.bu.edu\/eng\/files\/2023\/04\/22-1332-ENGFACULTY-015-scaled.jpg 1708w\" sizes=\"(max-width: 258px) 100vw, 258px\" \/><figcaption id=\"caption-attachment-139002\" class=\"wp-caption-text\"><em>Siddharth Ramachandran (ECE, Physics, MSE)<\/em><\/figcaption><\/figure>\n<p>In <a href=\"https:\/\/www.science.org\/doi\/10.1126\/science.add1874\" target=\"_blank\" rel=\"noopener noreferrer\">a new paper<\/a> published in <em><u><a href=\"https:\/\/www.science.org\/\" target=\"_blank\" rel=\"noopener noreferrer\">Science,<\/a><\/u><\/em> Ma and Ramachandran, along with industry collaborator Poul Kristensen of OFS Optics, demonstrate their groundbreaking solution\u2014one which not only cracks the problem of the upcoming capacity crunch, but may also yield a more energy-efficient means of signal transmission than traditional methods.<\/p>\n<p>One existing approach to alleviating capacity crunch involves configuring an optical fiber to support several separate data channels. Light travels down these channels in spatially distinct patterns, each of which carries as much data as a single standard fiber. Ramachandran and his team had <a href=\"https:\/\/www.science.org\/doi\/10.1126\/science.1237861\" target=\"_blank\" rel=\"noopener noreferrer\">previously<\/a> played a pivotal role in the development of this concept, akin to expanding the number of lanes in a highway to allow for increased traffic. Unfortunately, this tends to lead to \u201ccrashes\u201d\u2014information leaking between channels. This leakage corrupts every channel, thereby rendering information transmitted in all channels irretrievable&#8211;making this method a stopgap at best, not an effective solution.<\/p>\n<p>Instead of thinking in terms of cars and roads, Ramachandran suggests a more celestial framework.<\/p>\n<p>\u201cHigh-topological charge light beams\u201d behave differently from the standard beams used in optical communications today; rather than moving in a straight line, they twist as they travel, generating a \u201ccentrifugal barrier\u201d similar to those created by the rotation of binary stars. Just as centrifugal barriers keep such stars from crashing into one another, they can also operate to keep these unusual light beams contained within an optical fiber over significant distances. That is, these twisted beams do not need total internal reflection, previously thought to be necessary for transmitting light, to remain confined to the optical fiber. Unlike total internal reflection, this effect is also significantly more robust, allowing for many more data channels, without that pesky leakage problem.<\/p>\n<p>Ramachandran\u2019s team has successfully demonstrated this new method by packing as many as 50 data channels into a single kilometer-long optical fiber; 25 times the capacity of conventional fibers. They theorize that this improvement is only the beginning\u2014and if their approach is as scalable as they suspect, it could have a truly global impact.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Researchers\u2019 new method for scaling up data capacity in optical fibers echoes astronomical phenomena\u2014with significant implications for tomorrow\u2019s internet.<\/p>\n","protected":false},"author":2662,"featured_media":138999,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[236,977,240,907,1056,1],"tags":[760],"_links":{"self":[{"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/posts\/138997"}],"collection":[{"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/users\/2662"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/comments?post=138997"}],"version-history":[{"count":5,"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/posts\/138997\/revisions"}],"predecessor-version":[{"id":139005,"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/posts\/138997\/revisions\/139005"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/media\/138999"}],"wp:attachment":[{"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/media?parent=138997"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/categories?post=138997"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/tags?post=138997"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}