{"id":337,"date":"2025-08-27T20:11:19","date_gmt":"2025-08-27T11:11:19","guid":{"rendered":"https:\/\/www.hulinks.co.jp\/en\/?page_id=337"},"modified":"2025-10-29T16:07:59","modified_gmt":"2025-10-29T07:07:59","slug":"cold-mirror","status":"publish","type":"page","link":"https:\/\/www.hulinks.co.jp\/en\/tfcalc\/examples\/list-of-coating-design\/cold-mirror\/","title":{"rendered":"Cold Mirror"},"content":{"rendered":"\n<h1 class=\"wp-block-heading is-style-nostyle\">List of coating design exapmles<\/h1>\n\n\n\n<h2 class=\"wp-block-heading is-style-bottomline\">Cold Mirror<\/h2>\n\n\n\n<p>A cold mirror reflects short wavelengths and transmits long wavelengths. The are many applications for this type of coating. In this example, we require that the coating consist of layers of SiO2 and TiO2 on a glass substrate and have the following performance at normal incidence:<\/p>\n\n\n\n<p>&gt; 90% reflectance for 380-750 nm<\/p>\n\n\n\n<p>&lt; 10% reflectance for 800-1000 nm<\/p>\n\n\n\n<p>In TFCalc it is very easy to enter these requirements using continuous targets. We will use TFCalc\u2019s needle\/tunneling optimization to design the coating from \u201cscratch\u201d. That is, we will begin the design process with a single thin layer of TiO2 and allow TFCalc to increase the thickness and number of layers in the design. TFCalc finds a design in a few minutes. After we remove two thin layers and reoptimize the design, an acceptable 21-layer design is found:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"477\" height=\"271\" src=\"https:\/\/www.hulinks.co.jp\/en\/wp-content\/uploads\/sites\/2\/software\/tfcalc\/tf_cold_1.gif\" alt=\"\" class=\"wp-image-338\" \/><\/figure><\/div>\n\n\n<div style=\"height:10px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p>The prime difficulty with this type of coating is the design of the reflector. After an acceptable reflector has been designed, it is usually easy to extend the transmitting region. For instance, the plot below shows the 21-layer design extended to 2000 nm.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"468\" height=\"271\" src=\"https:\/\/www.hulinks.co.jp\/en\/wp-content\/uploads\/sites\/2\/software\/tfcalc\/tf_cold_2.gif\" alt=\"\" class=\"wp-image-339\" \/><\/figure><\/div>\n\n\n<div style=\"height:10px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p>Here are the designs, starting with the layer closest to the substrate, and with thicknesses given in nm:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>TIO2      44.21     33.76\nSIO2     102.57    124.04\nTIO2      43.97     28.39\nSIO2      73.13     66.36\nTIO2      42.56     51.05\nSIO2      82.52     86.41\nTIO2      48.92     51.97\nSIO2      87.18     88.77\nTIO2      46.48     39.55\nSIO2      66.56     70.41\nTIO2      36.16     36.85\nSIO2     162.54    162.37\nTIO2      53.07     53.15\nSIO2      97.19    102.08\nTIO2      79.13     81.48\nSIO2     102.19     99.64\nTIO2      67.77     61.86\nSIO2     128.87    137.38\nTIO2      53.24     51.30\nSIO2     158.61    191.13\nTIO2      34.40     19.03<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>List of coating design exapmles Cold Mirror A cold mirror reflects short wavelengths and transmits long wavelengths. The are many applications for this type of coating. In this example, we require that the coating consist of layers of SiO2 and TiO2 on a glass substrate and have the following performance at normal incidence: &gt; 90%&#8230;<\/p>\n","protected":false},"author":15,"featured_media":0,"parent":258,"menu_order":27,"comment_status":"closed","ping_status":"closed","template":"liquid.php","meta":{"footnotes":""},"tags":[],"class_list":["post-337","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.hulinks.co.jp\/en\/wp-json\/wp\/v2\/pages\/337","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hulinks.co.jp\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.hulinks.co.jp\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.hulinks.co.jp\/en\/wp-json\/wp\/v2\/users\/15"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hulinks.co.jp\/en\/wp-json\/wp\/v2\/comments?post=337"}],"version-history":[{"count":3,"href":"https:\/\/www.hulinks.co.jp\/en\/wp-json\/wp\/v2\/pages\/337\/revisions"}],"predecessor-version":[{"id":689,"href":"https:\/\/www.hulinks.co.jp\/en\/wp-json\/wp\/v2\/pages\/337\/revisions\/689"}],"up":[{"embeddable":true,"href":"https:\/\/www.hulinks.co.jp\/en\/wp-json\/wp\/v2\/pages\/258"}],"wp:attachment":[{"href":"https:\/\/www.hulinks.co.jp\/en\/wp-json\/wp\/v2\/media?parent=337"}],"wp:term":[{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.hulinks.co.jp\/en\/wp-json\/wp\/v2\/tags?post=337"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}