{"id":1371,"date":"2021-08-10T09:09:35","date_gmt":"2021-08-10T09:09:35","guid":{"rendered":"https:\/\/blog.amt.in\/?p=1371"},"modified":"2021-08-10T09:09:35","modified_gmt":"2021-08-10T09:09:35","slug":"introduction-to-optical-computing","status":"publish","type":"post","link":"https:\/\/blog.amt.in\/index.php\/2021\/08\/10\/introduction-to-optical-computing\/","title":{"rendered":"Introduction to Optical Computing"},"content":{"rendered":"

Optical\u00c2\u00a0or\u00c2\u00a0photonic computing\u00c2\u00a0uses\u00c2\u00a0photons\u00c2\u00a0produced by\u00c2\u00a0lasers\u00c2\u00a0or\u00c2\u00a0diodes\u00c2\u00a0for computation. For decades, photons have promised to allow a higher\u00c2\u00a0bandwidth\u00c2\u00a0than the\u00c2\u00a0electrons\u00c2\u00a0used in conventional computers.<\/p>\n

Most research projects focus on replacing current computer components with optical equivalents, resulting in an optical\u00c2\u00a0digital computer\u00c2\u00a0system processing\u00c2\u00a0binary data. This approach appears to offer the best short-term prospects for commercial optical computing, since optical components could be integrated into traditional computers to produce an optical-electronic hybrid. However,\u00c2\u00a0optoelectronic\u00c2\u00a0devices lose 30% of their energy converting electronic energy into photons and back; this conversion also slows the transmission of messages. All-optical computers eliminate the need for optical-electrical-optical (OEO) conversions, thus lessening the need for electrical power.<\/p>\n

The fundamental building block of modern electronic computers is the\u00c2\u00a0transistor. To replace electronic components with optical ones, an equivalent\u00c2\u00a0optical transistor\u00c2\u00a0is required. This is achieved using materials with a\u00c2\u00a0non-linear refractive index. In particular, materials exist\u00c2\u00a0where the intensity of incoming light affects the intensity of the light transmitted through the material in a similar manner to the current response of a bipolar transistor. Such an optical transistor\u00c2\u00a0can be used to create optical\u00c2\u00a0logic gates,\u00c2\u00a0which in turn are assembled into the higher level components of the computer’s\u00c2\u00a0CPU. These will be nonlinear optical crystals used to manipulate light beams into controlling other light beams.<\/p>\n

A significant challenge to optical computing is that computation is a\u00c2\u00a0nonlinear\u00c2\u00a0process in which multiple signals must interact. Light, which is an\u00c2\u00a0electromagnetic wave, can only interact with another electromagnetic wave in the presence of electrons in a material,\u00c2\u00a0and the strength of this interaction is much weaker for electromagnetic waves, such as light, than for the electronic signals in a conventional computer. This may result in the processing elements for an optical computer requiring more power and larger dimensions than those for a conventional electronic computer using transistors.<\/p>\n

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A further misconception is that since light can travel much faster than the\u00c2\u00a0drift velocity\u00c2\u00a0of electrons, and at frequencies measured in\u00c2\u00a0THz, optical transistors should be capable of extremely high frequencies. However, any electromagnetic wave must obey the\u00c2\u00a0transform limit, and therefore the rate at which an optical transistor can respond to a signal is still limited by its\u00c2\u00a0spectral bandwidth. However, in\u00c2\u00a0fiber optic communications, practical limits such as\u00c2\u00a0dispersion\u00c2\u00a0often constrain\u00c2\u00a0channels\u00c2\u00a0to bandwidths of 10s of GHz, only slightly better than many silicon transistors. Obtaining dramatically faster operation than electronic transistors would therefore require practical methods of transmitting\u00c2\u00a0ultra-short pulses\u00c2\u00a0down highly dispersive wave-guides.<\/div>\n
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Resonators\u00c2\u00a0are especially useful in photonic logic, since they allow a build-up of energy from\u00c2\u00a0constructive interference, thus enhancing optical nonlinear effects.<\/p>\n

Other approaches currently being investigated include photonic logic at a\u00c2\u00a0molecular level, using\u00c2\u00a0photo-luminescent\u00c2\u00a0chemicals. In a recent demonstration, Witlicki et al. performed logical operations using molecules and\u00c2\u00a0SERS.<\/p>\n

The above is a brief about Optical Computing. Watch this space for more updates on the latest trends in Technology<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

Optical\u00c2\u00a0or\u00c2\u00a0photonic computing\u00c2\u00a0uses\u00c2\u00a0photons\u00c2\u00a0produced by\u00c2\u00a0lasers\u00c2\u00a0or\u00c2\u00a0diodes\u00c2\u00a0for computation. For<\/p>\n","protected":false},"author":1,"featured_media":1373,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[185,186,7],"tags":[188,187,18],"class_list":["post-1371","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-optical-computing","category-photons","category-techtrends","tag-optical-computing","tag-photons","tag-technology"],"_links":{"self":[{"href":"https:\/\/blog.amt.in\/index.php\/wp-json\/wp\/v2\/posts\/1371","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.amt.in\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.amt.in\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.amt.in\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.amt.in\/index.php\/wp-json\/wp\/v2\/comments?post=1371"}],"version-history":[{"count":1,"href":"https:\/\/blog.amt.in\/index.php\/wp-json\/wp\/v2\/posts\/1371\/revisions"}],"predecessor-version":[{"id":1372,"href":"https:\/\/blog.amt.in\/index.php\/wp-json\/wp\/v2\/posts\/1371\/revisions\/1372"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.amt.in\/index.php\/wp-json\/wp\/v2\/media\/1373"}],"wp:attachment":[{"href":"https:\/\/blog.amt.in\/index.php\/wp-json\/wp\/v2\/media?parent=1371"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.amt.in\/index.php\/wp-json\/wp\/v2\/categories?post=1371"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.amt.in\/index.php\/wp-json\/wp\/v2\/tags?post=1371"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}