{"id":82,"date":"2013-08-30T21:50:29","date_gmt":"2013-08-30T21:50:29","guid":{"rendered":"http:\/\/dev.blogs.soton.ac.uk\/thz\/?page_id=82"},"modified":"2013-08-30T21:50:29","modified_gmt":"2013-08-30T21:50:29","slug":"novel-thz-emitters","status":"publish","type":"page","link":"https:\/\/blog.soton.ac.uk\/thz\/research\/novel-thz-emitters\/","title":{"rendered":"Novel THz emitters"},"content":{"rendered":"<div dir=\"ltr\">\n<p>The photo-Dember (PD) effect is a THz emission mechanism based on ultrafast carrier transport. THz radiation is produced by illumination of a semiconductor surface by an ultrafast near infrared laser with energy above the bandgap (usually Ti:S). The strong absorption of light near the surface creates a large carrier gradient of electrons and holes, which initiates a diffusion current. Because of the different mobilities, electrons and holes spatially separate on a picosecond time scale.<\/p>\n<p>In the THz laboratories group we simulated the diffusion of the carriers in combination with a theoretical analysis of the emission of a dipole under a metal sheet. We have developed an emitter that works based on diffusion currents and the suppression of dipoles under a semi-infinite metallic sheet [1, 2]. We have experimentally demonstrated the emitters using semiconductor (GaAs) substrates. This mechanism indicates a novel method of generating THz radiation that is based on the diffusion current created by ultrafast radiation but also uses the inhibition of radiation due to a metal surface. This concept gives rise to design proposals for a series of emitters, which would give similar performance to a Photo-conductive antenna, which is currently the standard THz emitter. This work is funded by EPSRC for the development of a high power THz spectrometer based on PD emitters and THz lasers.<\/p>\n<ol>\n<li>G. Klatt, et al, \u201cTerahertz emission from lateral photo-Dember currents,\u201d Opt. Express 18, 4939\u20134947 (2010).<\/li>\n<li>M. E. Barnes, et al., &#8220;Terahertz emission by diffusion of carriers and metal-mask dipole inhibition of radiation,&#8221; Opt. Express\u00a020, 8898-8906 (2012)<\/li>\n<\/ol>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>The photo-Dember (PD) effect is a THz emission mechanism based on ultrafast carrier transport. THz radiation is produced by illumination of a semiconductor surface by an ultrafast near infrared laser with energy above the bandgap (usually Ti:S). The strong absorption of light near the surface creates a large carrier gradient of electrons and holes, which &hellip; <\/p>\n<p><a class=\"more-link block-button\" href=\"https:\/\/blog.soton.ac.uk\/thz\/research\/novel-thz-emitters\/\">Continue reading &raquo;<\/a><\/p>\n","protected":false},"author":84132,"featured_media":0,"parent":23,"menu_order":0,"comment_status":"open","ping_status":"open","template":"","meta":{"footnotes":""},"class_list":["post-82","page","type-page","status-publish","hentry","nodate"],"_links":{"self":[{"href":"https:\/\/blog.soton.ac.uk\/thz\/wp-json\/wp\/v2\/pages\/82","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.soton.ac.uk\/thz\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/blog.soton.ac.uk\/thz\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/blog.soton.ac.uk\/thz\/wp-json\/wp\/v2\/users\/84132"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.soton.ac.uk\/thz\/wp-json\/wp\/v2\/comments?post=82"}],"version-history":[{"count":0,"href":"https:\/\/blog.soton.ac.uk\/thz\/wp-json\/wp\/v2\/pages\/82\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/blog.soton.ac.uk\/thz\/wp-json\/wp\/v2\/pages\/23"}],"wp:attachment":[{"href":"https:\/\/blog.soton.ac.uk\/thz\/wp-json\/wp\/v2\/media?parent=82"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}