{"id":2908,"date":"2025-06-16T16:13:44","date_gmt":"2025-06-16T14:13:44","guid":{"rendered":"https:\/\/nanophotonics.fizyka.umk.pl\/?page_id=2908"},"modified":"2025-06-16T16:15:20","modified_gmt":"2025-06-16T14:15:20","slug":"near-field-microscopy-and-tim0enhanced-techniques","status":"publish","type":"page","link":"https:\/\/nanophotonics.fizyka.umk.pl\/?page_id=2908&lang=en","title":{"rendered":"Near-field microscopy and tip-enhanced techniques"},"content":{"rendered":"\n<div id=\"wp-block-themeisle-blocks-advanced-columns-409da980\" class=\"wp-block-themeisle-blocks-advanced-columns has-1-columns has-desktop-equal-layout has-tablet-equal-layout has-mobile-equal-layout has-vertical-unset has-default-gap\"><div class=\"wp-block-themeisle-blocks-advanced-columns-overlay\"><\/div><div class=\"innerblocks-wrap\">\n<div id=\"wp-block-themeisle-blocks-advanced-column-a8307f1e\" class=\"wp-block-themeisle-blocks-advanced-column\">\n<p><\/p>\n\n\n\n<p class=\"has-normal-font-size\"><strong>Tip-enhanced near-field optical microscopy<\/strong><br>The technique we use relies on the locally enhanced optical fields close to a laser illuminated, sharp metal tip. The sample is raster scanned below the tip which can act as a highly confined excitation source providing a considerable signal enhancement and spectroscopic images at very high spatial resolution.<\/p>\n<\/div>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:33.33%\"><div class=\"wp-block-image\">\n<figure class=\"alignright size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"1024\" src=\"https:\/\/nanophotonics.fizyka.umk.pl\/wp-content\/uploads\/2024\/09\/Designer.jpeg\" alt=\"Tip-enhanced spectroscopy\" class=\"wp-image-2496\" style=\"width:314px;height:314px\" srcset=\"https:\/\/nanophotonics.fizyka.umk.pl\/wp-content\/uploads\/2024\/09\/Designer.jpeg 1024w, https:\/\/nanophotonics.fizyka.umk.pl\/wp-content\/uploads\/2024\/09\/Designer-300x300.jpeg 300w, https:\/\/nanophotonics.fizyka.umk.pl\/wp-content\/uploads\/2024\/09\/Designer-150x150.jpeg 150w, https:\/\/nanophotonics.fizyka.umk.pl\/wp-content\/uploads\/2024\/09\/Designer-768x768.jpeg 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure><\/div><\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:66.66%\">\n<p class=\"has-text-align-left has-small-font-size\">Our experimental setup is based on an inverted optical microscope with an x, y scan stage for raster scanning a transparent sample. The excitation is provided by a HeNe laser operating at 632.8 nm that is reflected by a dichroic beam splitter and focused by a high numerical aperture objective (1.4 NA) on the sample surface.<\/p>\n\n\n\n<p class=\"has-small-font-size\">A sharp gold tip is positioned near the focus of the beam and maintained above the sample surface at a distance of ~1-2 nm by means of a sensitive shear-force feedback mechanism. The gold tips with a radius of 10-15 nm are produced by electrochemical etching.<\/p>\n\n\n\n<p class=\"has-small-font-size\">Both Raman scattered light and luminescence are collected with the same objective, transmitted by the beam splitter and separated by a long pass filter. The signal is then detected either by a combination of a spectrograph and a charged coupled device (CCD) or by avalanche photodiodes (APDs).<\/p>\n\n\n\n<p class=\"has-small-font-size\">Tip-enhanced near-field microscopy allows for optical imaging with a spatial resolution below 20 nm and spectroscopy on a nanometer scale.<\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Our experimental setup is based on an inverted optical microscope with an x, y scan stage for raster scanning a transparent sample. The excitation is provided by a HeNe laser operating at 632.8 nm that is reflected by a dichroic beam splitter and focused by a high numerical aperture objective (1.4 NA) on the sample&hellip;&nbsp;<a href=\"https:\/\/nanophotonics.fizyka.umk.pl\/?page_id=2908&#038;lang=en\" rel=\"bookmark\">Read More &raquo;<span class=\"screen-reader-text\">Near-field microscopy and tip-enhanced techniques<\/span><\/a><\/p>\n","protected":false},"author":71,"featured_media":0,"parent":0,"menu_order":5,"comment_status":"closed","ping_status":"closed","template":"","meta":{"neve_meta_sidebar":"full-width","neve_meta_container":"","neve_meta_enable_content_width":"on","neve_meta_content_width":100,"neve_meta_title_alignment":"","neve_meta_author_avatar":"","neve_post_elements_order":"","neve_meta_disable_header":"","neve_meta_disable_footer":"","neve_meta_disable_title":"on","_themeisle_gutenberg_block_has_review":false,"footnotes":""},"class_list":["post-2908","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/nanophotonics.fizyka.umk.pl\/index.php?rest_route=\/wp\/v2\/pages\/2908","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nanophotonics.fizyka.umk.pl\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/nanophotonics.fizyka.umk.pl\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/nanophotonics.fizyka.umk.pl\/index.php?rest_route=\/wp\/v2\/users\/71"}],"replies":[{"embeddable":true,"href":"https:\/\/nanophotonics.fizyka.umk.pl\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2908"}],"version-history":[{"count":2,"href":"https:\/\/nanophotonics.fizyka.umk.pl\/index.php?rest_route=\/wp\/v2\/pages\/2908\/revisions"}],"predecessor-version":[{"id":2911,"href":"https:\/\/nanophotonics.fizyka.umk.pl\/index.php?rest_route=\/wp\/v2\/pages\/2908\/revisions\/2911"}],"wp:attachment":[{"href":"https:\/\/nanophotonics.fizyka.umk.pl\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2908"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}