{"id":40,"date":"2021-09-23T01:14:05","date_gmt":"2021-09-23T01:14:05","guid":{"rendered":"https:\/\/live-optics-wp.pantheonsite.io\/chalifoux\/?page_id=40"},"modified":"2021-10-04T16:52:47","modified_gmt":"2021-10-04T16:52:47","slug":"laser-stress-figuring","status":"publish","type":"page","link":"https:\/\/wp.optics.arizona.edu\/chalifoux\/research\/laser-stress-figuring\/","title":{"rendered":"Laser stress figuring"},"content":{"rendered":"\n<p style=\"font-size:18px\">Controlling low spatial frequency height errors during fabrication of thin substrates is difficult due to their low stiffness. Furthermore, many reflective coatings exhibit difficult-to-predict stress that bends these compliant substrates after material-removal processes have already figured them. Stress-based figuring, on the other hand, can accurately correct figure errors with magnitudes of tens of micrometers, even after coatings have been applied.<\/p>\n\n\n\n<p style=\"font-size:18px\">Focusing an ultrashort pulsed (USP) laser into transparent materials results in nonlinear absorption and subsequent extreme heating and cooling to generate stress. We are developing a process to control this stress within glass mirror substrates to correct figure errors.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"256\" src=\"https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-content\/uploads\/sites\/95\/2021\/10\/Laser-stress-figuring-cartoon-1024x256.png\" alt=\"\" class=\"wp-image-114\" srcset=\"https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-content\/uploads\/sites\/95\/2021\/10\/Laser-stress-figuring-cartoon-1024x256.png 1024w, https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-content\/uploads\/sites\/95\/2021\/10\/Laser-stress-figuring-cartoon-300x75.png 300w, https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-content\/uploads\/sites\/95\/2021\/10\/Laser-stress-figuring-cartoon-768x192.png 768w, https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-content\/uploads\/sites\/95\/2021\/10\/Laser-stress-figuring-cartoon-1536x384.png 1536w, https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-content\/uploads\/sites\/95\/2021\/10\/Laser-stress-figuring-cartoon-2048x512.png 2048w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption>Laser stress figuring concept. We generate controllable stress with USP lasers to bend the substrate without affecting mid spatial frequency (MSF) errors or coatings.<\/figcaption><\/figure><\/div>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-content\/uploads\/sites\/95\/2021\/10\/DSC_0499-2-1024x576.jpg\" alt=\"\" class=\"wp-image-113\" width=\"580\" height=\"326\" srcset=\"https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-content\/uploads\/sites\/95\/2021\/10\/DSC_0499-2-1024x576.jpg 1024w, https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-content\/uploads\/sites\/95\/2021\/10\/DSC_0499-2-300x169.jpg 300w, https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-content\/uploads\/sites\/95\/2021\/10\/DSC_0499-2-768x432.jpg 768w, https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-content\/uploads\/sites\/95\/2021\/10\/DSC_0499-2-1536x864.jpg 1536w, https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-content\/uploads\/sites\/95\/2021\/10\/DSC_0499-2-2048x1152.jpg 2048w\" sizes=\"auto, (max-width: 580px) 100vw, 580px\" \/><figcaption> A 100 mm diameter fused silica mirror ready just after laser stress figuring<\/figcaption><\/figure><\/div>\n\n\n\n<p style=\"font-size:18px\">Controlling three components of in-plane stress is necessary for full-aperture accurate figure correction. We have developed procedures and software to implement this. Our recent results show consistent reductions from 3.6 \u03bcm RMS figure error (first 6 orders of Zernike polynomials) to &lt;0.05 \u03bcm RMS in 2-3 correction cycles. We are working to improve this further.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Publications<\/h2>\n\n\n\n<p>B. D. Chalifoux, I. J. Arnold, K. A. Laverty, \u201cFigure correction of glass mirrors using ultrafast lasers to generate controllable stress,\u201d OSA Optical Design and Fabrication Congress, OW4B.2 (2021).<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Controlling low spatial frequency height errors during fabrication of thin substrates is difficult due to their low stiffness. Furthermore, many reflective coatings exhibit difficult-to-predict stress that bends these compliant substrates after material-removal processes have already figured them. Stress-based figuring, on the other hand, can accurately correct figure errors with magnitudes of tens of micrometers, even after coatings have been applied.<\/p>\n","protected":false},"author":141,"featured_media":0,"parent":8,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-40","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-json\/wp\/v2\/pages\/40","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-json\/wp\/v2\/users\/141"}],"replies":[{"embeddable":true,"href":"https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-json\/wp\/v2\/comments?post=40"}],"version-history":[{"count":7,"href":"https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-json\/wp\/v2\/pages\/40\/revisions"}],"predecessor-version":[{"id":133,"href":"https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-json\/wp\/v2\/pages\/40\/revisions\/133"}],"up":[{"embeddable":true,"href":"https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-json\/wp\/v2\/pages\/8"}],"wp:attachment":[{"href":"https:\/\/wp.optics.arizona.edu\/chalifoux\/wp-json\/wp\/v2\/media?parent=40"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}