{"id":2840,"date":"2026-08-19T05:42:14","date_gmt":"2026-08-19T05:42:14","guid":{"rendered":"https:\/\/www.sapphire-windows.com\/?p=2840"},"modified":"2026-08-19T05:42:26","modified_gmt":"2026-08-19T05:42:26","slug":"rectangular-sapphire-windows-corner-radius-edge-stress-flatness-and-mounting-design","status":"publish","type":"post","link":"https:\/\/www.sapphire-windows.com\/ar\/rectangular-sapphire-windows-corner-radius-edge-stress-flatness-and-mounting-design\/","title":{"rendered":"Rectangular Sapphire Windows: Corner Radius, Edge Stress, Flatness and Mounting Design"},"content":{"rendered":"<p class=\"wp-block-paragraph\"><a href=\"https:\/\/www.sapphire-windows.com\/ar\/product-category\/%d9%86%d9%88%d8%a7%d9%81%d8%b0-%d9%85%d9%86-%d8%a7%d9%84%d9%8a%d8%a7%d9%82%d9%88%d8%aa\/\">Rectangular sapphire windows <\/a>are widely used in optical sensors, industrial inspection systems, semiconductor equipment, laser systems, high-pressure instruments and harsh-environment viewing assemblies.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Compared with circular sapphire windows, rectangular windows can make better use of available installation space and provide a larger usable field of view. However, their geometry also creates several additional engineering challenges.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The most important are:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Corner stress concentration<\/li>\n\n\n\n<li>Corner radius selection<\/li>\n\n\n\n<li>\u062a\u0634\u0642\u0642 \u0627\u0644\u062d\u0648\u0627\u0641<\/li>\n\n\n\n<li>Unsupported span<\/li>\n\n\n\n<li>\u0633\u0645\u0643 \u0627\u0644\u0646\u0627\u0641\u0630\u0629<\/li>\n\n\n\n<li>\u0627\u0644\u062a\u0633\u0637\u064a\u062d<\/li>\n\n\n\n<li>\u0627\u0644\u062a\u0648\u0627\u0632\u064a<\/li>\n\n\n\n<li>Mounting-seat accuracy<\/li>\n\n\n\n<li>Clamping stress<\/li>\n\n\n\n<li>Thermal expansion mismatch<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">A rectangular sapphire window should therefore not simply be treated as a circular window with four sides removed.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Its mechanical design, optical specifications and mounting method should be evaluated together.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img fetchpriority=\"high\" decoding=\"async\" width=\"1024\" height=\"768\" src=\"https:\/\/www.sapphire-windows.com\/wp-content\/uploads\/2026\/08\/Rectangular-Sapphire-Windows-1024x768.png\" alt=\"\" class=\"wp-image-2841\" srcset=\"https:\/\/www.sapphire-windows.com\/wp-content\/uploads\/2026\/08\/Rectangular-Sapphire-Windows-1024x768.png 1024w, https:\/\/www.sapphire-windows.com\/wp-content\/uploads\/2026\/08\/Rectangular-Sapphire-Windows-300x225.png 300w, https:\/\/www.sapphire-windows.com\/wp-content\/uploads\/2026\/08\/Rectangular-Sapphire-Windows-768x576.png 768w, https:\/\/www.sapphire-windows.com\/wp-content\/uploads\/2026\/08\/Rectangular-Sapphire-Windows-16x12.png 16w, https:\/\/www.sapphire-windows.com\/wp-content\/uploads\/2026\/08\/Rectangular-Sapphire-Windows-600x450.png 600w, https:\/\/www.sapphire-windows.com\/wp-content\/uploads\/2026\/08\/Rectangular-Sapphire-Windows.png 1448w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">1. Why Use a Rectangular Sapphire Window?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Rectangular and square sapphire windows are commonly selected when the optical opening or equipment housing is not circular.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u062a\u0634\u0645\u0644 \u0627\u0644\u062a\u0637\u0628\u064a\u0642\u0627\u062a \u0627\u0644\u0646\u0645\u0648\u0630\u062c\u064a\u0629 \u0645\u0627 \u064a\u0644\u064a:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Camera protection windows<\/li>\n\n\n\n<li>\u0623\u0646\u0638\u0645\u0629 \u0627\u0644\u0631\u0624\u064a\u0629 \u0627\u0644\u0635\u0646\u0627\u0639\u064a\u0629<\/li>\n\n\n\n<li>\u0627\u0644\u0645\u0633\u062a\u0634\u0639\u0631\u0627\u062a \u0627\u0644\u0636\u0648\u0626\u064a\u0629<\/li>\n\n\n\n<li>\u0645\u0639\u062f\u0627\u062a \u0627\u0644\u0644\u064a\u0632\u0631<\/li>\n\n\n\n<li>\u063a\u0631\u0641 \u062a\u0641\u0631\u064a\u063a \u0627\u0644\u0647\u0648\u0627\u0621<\/li>\n\n\n\n<li>\u0645\u0639\u062f\u0627\u062a \u0645\u0639\u0627\u0644\u062c\u0629 \u0623\u0634\u0628\u0627\u0647 \u0627\u0644\u0645\u0648\u0635\u0644\u0627\u062a<\/li>\n\n\n\n<li>Furnace observation windows<\/li>\n\n\n\n<li>High-pressure viewing systems<\/li>\n\n\n\n<li>Aerospace optical assemblies<\/li>\n\n\n\n<li>Harsh-environment displays<\/li>\n\n\n\n<li>\u0627\u0644\u0623\u062f\u0648\u0627\u062a \u0627\u0644\u0639\u0644\u0645\u064a\u0629<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">A rectangular window can provide a larger clear aperture within a limited enclosure.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For example, if an optical sensor requires a wide horizontal field of view, a rectangular sapphire window may use the available space more efficiently than a circular component.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">However, this advantage comes with a mechanical tradeoff.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A rectangular plate does not distribute stress as uniformly as a circular plate.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">2. Why Are the Corners Important?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">The corners are one of the most critical areas of a rectangular sapphire window.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Sharp internal or external geometric transitions tend to increase local stress.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This becomes particularly important because sapphire is a hard but brittle single-crystal material.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Unlike many metals, sapphire cannot relieve local stress through significant plastic deformation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If a small machining flaw exists near a highly stressed corner, the combination of:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>defect + tensile stress<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">can increase the probability of crack initiation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For this reason, rectangular sapphire windows are often manufactured with controlled corner radii rather than perfectly sharp corners.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">3. Corner Radius and Stress Concentration<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Consider two rectangular sapphire windows with identical overall dimensions and thickness.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Design A<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">50 \u00d7 30 \u00d7 3 mm<br>Corner radius: R0.2 mm<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Design B<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">50 \u00d7 30 \u00d7 3 mm<br>Corner radius: R3 mm<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Although their overall size is almost identical, their mechanical behavior may differ.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The larger corner radius provides a smoother geometric transition and can reduce local stress concentration.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This does not mean that every rectangular window should use the largest possible radius.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Corner radius must also match:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Housing geometry<\/li>\n\n\n\n<li>\u0627\u0644\u0641\u062a\u062d\u0629 \u0627\u0644\u0635\u0627\u0641\u064a\u0629<\/li>\n\n\n\n<li>Optical field of view<\/li>\n\n\n\n<li>Sealing structure<\/li>\n\n\n\n<li>Available mounting space<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Therefore, corner radius is normally an engineering compromise between mechanical reliability and usable optical area.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">4. Do Not Specify \u201cSharp Corners\u201d Unless They Are Truly Necessary<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Engineering drawings sometimes specify rectangular sapphire windows with extremely small corner radii because the designer wants to maximize clear aperture.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This can create manufacturing and reliability problems.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Sapphire is typically shaped using diamond grinding and precision machining.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Producing an extremely sharp corner can increase the difficulty of:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Grinding<\/li>\n\n\n\n<li>Polishing<\/li>\n\n\n\n<li>Edge finishing<\/li>\n\n\n\n<li>Handling<\/li>\n\n\n\n<li>Inspection<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">It can also make the corner more vulnerable to chipping.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If a truly sharp corner is not required by the assembly, allowing a reasonable radius can improve manufacturability and reduce damage risk.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A better RFQ may specify:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>4 \u00d7 R1.0 mm<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">rather than simply:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Corners sharp<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">unless the optical or mechanical design genuinely requires sharp geometry.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">5. Corner Radius Is Different From Edge Chamfer<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">These two specifications should not be confused.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Corner Radius<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The radius viewed from the front surface of the rectangular window.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Example:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>R2 mm at four corners<\/strong><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Edge Chamfer<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The bevel applied around the thickness direction of the component.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Example:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>0.3 \u00d7 45\u00b0 chamfer<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A rectangular sapphire window may therefore simultaneously have:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Four R2 mm plan-view corners<\/li>\n\n\n\n<li>A 0.3 mm edge chamfer around its perimeter<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Both parameters influence manufacturing and handling performance.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">6. Edge Stress Is Often More Important Than the Center<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Under mechanical loading, the highest stress region depends on:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Window geometry<\/li>\n\n\n\n<li>Support structure<\/li>\n\n\n\n<li>Pressure<\/li>\n\n\n\n<li>\u0627\u0644\u0633\u064f\u0645\u0643<\/li>\n\n\n\n<li>\u0627\u0644\u0641\u062a\u062d\u0629 \u0627\u0644\u0635\u0627\u0641\u064a\u0629<\/li>\n\n\n\n<li>Mounting conditions<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">For rectangular windows, edges and corners deserve particular attention.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Potential edge-related defects include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Chips<\/li>\n\n\n\n<li>\u0627\u0644\u0634\u0642\u0648\u0642 \u0627\u0644\u062f\u0642\u064a\u0642\u0629<\/li>\n\n\n\n<li>Grinding marks<\/li>\n\n\n\n<li>\u0627\u0644\u0623\u0636\u0631\u0627\u0631 \u062a\u062d\u062a \u0627\u0644\u0633\u0637\u062d\u064a\u0629<\/li>\n\n\n\n<li>Uneven bevels<\/li>\n\n\n\n<li>Local scratches<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">A small defect in a highly stressed area can reduce the practical strength of the finished component.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is why edge quality should be included in the specification for structural or pressure-loaded sapphire windows.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">7. Edge Finish Options for Rectangular Sapphire Windows<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Depending on the application, the perimeter may be supplied with:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Ground Edge<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Suitable for applications where the edge is not optically active.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is normally the most economical option.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Fine-Ground Edge<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Provides improved edge finish and may reduce visible machining damage.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Polished Edge<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Used when:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The edge is optically active<\/li>\n\n\n\n<li>High cosmetic quality is required<\/li>\n\n\n\n<li>Internal reflection behavior matters<\/li>\n\n\n\n<li>The application has strict cleanliness requirements<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Chamfered Edge<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A small chamfer helps remove fragile sharp edges and improves handling.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Rounded Edge<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A controlled radius may be used for specialized mechanical designs.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The correct option depends on the mounting and optical function.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">8. Clear Aperture Should Be Defined Separately<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">For rectangular sapphire windows, the outside dimensions and optical clear aperture should be treated as separate parameters.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Example:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Overall size:<\/strong><br>50 \u00d7 30 mm<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Clear aperture:<\/strong><br>44 \u00d7 24 mm<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This leaves approximately 3 mm around the perimeter for mechanical support.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If the clear aperture is increased to:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">48 \u00d7 28 mm<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">the supported edge becomes much narrower.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That may affect:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Bending stress<\/li>\n\n\n\n<li>Mounting reliability<\/li>\n\n\n\n<li>Seal width<\/li>\n\n\n\n<li>Edge loading<\/li>\n\n\n\n<li>Fracture safety factor<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Therefore, maximizing clear aperture is not always mechanically desirable.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">9. Thickness Depends on Unsupported Span<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">A common mistake is choosing sapphire thickness only from the overall length and width.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The real mechanical loading depends strongly on the unsupported opening.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Consider:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Window A<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Sapphire size: 60 \u00d7 40 mm<br>Opening: 40 \u00d7 20 mm<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Window B<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Sapphire size: 60 \u00d7 40 mm<br>Opening: 56 \u00d7 36 mm<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Although the sapphire dimensions are identical, Window B has a much larger unsupported area.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Its bending stress and deflection may therefore be significantly greater.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For pressure-loaded applications, the supplier or mechanical engineer should evaluate:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Unsupported length<\/li>\n\n\n\n<li>Unsupported width<\/li>\n\n\n\n<li>\u0633\u0645\u0643 \u0627\u0644\u064a\u0627\u0642\u0648\u062a<\/li>\n\n\n\n<li>\u0641\u0631\u0642 \u0627\u0644\u0636\u063a\u0637<\/li>\n\n\n\n<li>Boundary condition<\/li>\n\n\n\n<li>\u062f\u0631\u062c\u0629 \u0627\u0644\u062d\u0631\u0627\u0631\u0629<\/li>\n\n\n\n<li>\u0645\u0639\u0627\u0645\u0644 \u0627\u0644\u0623\u0645\u0627\u0646<\/li>\n<\/ul>\n\n\n\n<h1 class=\"wp-block-heading\">10. Rectangular Windows Behave Differently From Circular Windows<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Circular windows are naturally symmetrical.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When uniformly loaded and evenly supported, stress tends to distribute around the circumference in a relatively predictable way.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Rectangular windows introduce:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Long and short axes<\/li>\n\n\n\n<li>Corners<\/li>\n\n\n\n<li>Different bending distances<\/li>\n\n\n\n<li>Unequal edge conditions<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Therefore, a thickness selected for a circular sapphire window of a similar area should not automatically be copied to a rectangular design.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For high-pressure or safety-critical applications, mechanical calculation or finite element analysis may be appropriate.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">11. Flatness Requirements<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Flatness describes how much the optical surface deviates from an ideal plane.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Typical specifications may be expressed as:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u03bb<\/li>\n\n\n\n<li>\u03bb\/2<\/li>\n\n\n\n<li>\u03bb\/4<\/li>\n\n\n\n<li>\u03bb\/10<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">at a specified reference wavelength.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The required flatness depends heavily on the application.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For a protective camera window, extremely tight flatness may not be necessary.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Precision imaging<\/li>\n\n\n\n<li>\u0627\u0644\u062a\u062f\u0627\u062e\u0644 \u0627\u0644\u0636\u0648\u0626\u064a<\/li>\n\n\n\n<li>\u0623\u0646\u0638\u0645\u0629 \u0627\u0644\u0644\u064a\u0632\u0631<\/li>\n\n\n\n<li>Beam delivery<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">tighter flatness may be important.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">12. Do Not Over-Specify Flatness<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Tighter flatness generally increases manufacturing difficulty and cost.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A buyer should therefore avoid specifying:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u03bb\/10 flatness<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">simply because it appears better than:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u03bb\/4<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If the application only requires a protective optical cover, the tighter specification may provide little practical benefit.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A more economical design specifies only the performance required by the optical system.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">13. Large Rectangular Windows Are More Difficult to Keep Flat<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">As sapphire window dimensions increase while thickness remains constant, controlling flatness generally becomes more challenging.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A thin rectangular plate can be more sensitive to:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Grinding stress<\/li>\n\n\n\n<li>Polishing stress<\/li>\n\n\n\n<li>Handling<\/li>\n\n\n\n<li>Mounting force<\/li>\n\n\n\n<li>Thermal gradients<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">For large windows, engineers may need to balance:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u0627\u0644\u0633\u064f\u0645\u0643<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">against<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Weight + cost + transmission + flatness + mechanical strength<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Increasing thickness may improve mechanical rigidity, but it also increases raw material and machining cost.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">14. Parallelism and Wedge<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Flatness and parallelism are different parameters.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u0627\u0644\u062a\u0633\u0637\u064a\u062d<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Describes the shape of an individual surface.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u0627\u0644\u062a\u0648\u0627\u0632\u064a<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Describes the angular relationship between the two major surfaces.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If the surfaces are not sufficiently parallel, the window effectively behaves like a weak prism.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This can cause:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u0627\u0646\u062d\u0631\u0627\u0641 \u0627\u0644\u0634\u0639\u0627\u0639<\/li>\n\n\n\n<li>Image displacement<\/li>\n\n\n\n<li>Alignment errors<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">For laser systems, parallelism or wedge should therefore be specified according to optical requirements.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">15. Mounting Design Is Critical<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Many sapphire window failures occur not during manufacturing but after installation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A well-manufactured rectangular sapphire window can be damaged by:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Uneven clamping<\/li>\n\n\n\n<li>Distorted housing<\/li>\n\n\n\n<li>Metal burrs<\/li>\n\n\n\n<li>Excessive bolt torque<\/li>\n\n\n\n<li>Point contact<\/li>\n\n\n\n<li>\u0627\u0644\u062a\u0645\u062f\u062f \u0627\u0644\u062d\u0631\u0627\u0631\u064a<\/li>\n\n\n\n<li>Improper gasket geometry<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The mounting system should distribute load as evenly as possible.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">16. Avoid Point Loading at the Corners<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Corners should not carry concentrated mechanical loads.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For example, a retaining frame that contacts only four small areas near the corners can create severe local stress.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A better design generally distributes load over a wider region.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Possible mounting approaches include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Continuous retaining frame<\/li>\n\n\n\n<li>O-ring support<\/li>\n\n\n\n<li>Engineered gasket<\/li>\n\n\n\n<li>Flexible adhesive<\/li>\n\n\n\n<li>Compliant intermediate layer<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The exact method depends on:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Pressure<\/li>\n\n\n\n<li>Vacuum<\/li>\n\n\n\n<li>\u062f\u0631\u062c\u0629 \u0627\u0644\u062d\u0631\u0627\u0631\u0629<\/li>\n\n\n\n<li>Chemical exposure<\/li>\n\n\n\n<li>Optical requirements<\/li>\n<\/ul>\n\n\n\n<h1 class=\"wp-block-heading\">17. O-Ring Mounting<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">O-rings are commonly used when sealing and mechanical compliance are both required.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A properly designed O-ring can:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Provide sealing<\/li>\n\n\n\n<li>Prevent direct metal-to-sapphire contact<\/li>\n\n\n\n<li>Accommodate small dimensional variation<\/li>\n\n\n\n<li>Distribute load<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">However, excessive O-ring compression can also create stress.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Important parameters include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>O-ring diameter<\/li>\n\n\n\n<li>Groove depth<\/li>\n\n\n\n<li>Compression ratio<\/li>\n\n\n\n<li>Material hardness<\/li>\n\n\n\n<li>Temperature capability<\/li>\n\n\n\n<li>\u0627\u0644\u062a\u0648\u0627\u0641\u0642 \u0627\u0644\u0643\u064a\u0645\u064a\u0627\u0626\u064a<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The O-ring groove should therefore be designed as part of the overall mechanical assembly.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">18. Retaining Frames and Clamping<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">A rectangular retaining frame is another common mounting method.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The frame should not force the sapphire to conform to an inaccurate mounting surface.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Avoid situations where:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>One corner contacts first<\/li>\n\n\n\n<li>Housing flatness is poor<\/li>\n\n\n\n<li>Fasteners are tightened unevenly<\/li>\n\n\n\n<li>Metal directly touches a sharp sapphire edge<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">For bolted frames, a controlled tightening sequence may help distribute load more uniformly.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">19. Housing Flatness Matters<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">If the mounting surface is warped, tightening the retaining structure can bend the sapphire.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This may create residual stress before the equipment is even operated.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For precision or heavily loaded assemblies, consider specifying:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Mounting-seat flatness<\/li>\n\n\n\n<li>Frame flatness<\/li>\n\n\n\n<li>\u0627\u0644\u062a\u0648\u0627\u0632\u064a<\/li>\n\n\n\n<li>Surface finish<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The window and housing should be treated as a mechanical system.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">20. Allow for Thermal Expansion<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Sapphire and metal housings expand differently as temperature changes.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This becomes important in:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Furnace equipment<\/li>\n\n\n\n<li>\u063a\u0631\u0641 \u062a\u0641\u0631\u064a\u063a \u0627\u0644\u0647\u0648\u0627\u0621<\/li>\n\n\n\n<li>Semiconductor processing<\/li>\n\n\n\n<li>\u0645\u0633\u062a\u0634\u0639\u0631\u0627\u062a \u062f\u0631\u062c\u0627\u062a \u0627\u0644\u062d\u0631\u0627\u0631\u0629 \u0627\u0644\u0639\u0627\u0644\u064a\u0629<\/li>\n\n\n\n<li>\u0623\u0646\u0638\u0645\u0629 \u0627\u0644\u0644\u064a\u0632\u0631<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">If a sapphire window is tightly constrained by a metal frame, heating can generate additional stress.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The design should therefore provide sufficient compliance for expected thermal movement.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This becomes even more important for large rectangular windows because dimensional changes along the long axis can be greater.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">21. Adhesive-Bonded Rectangular Sapphire Windows<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Adhesives are often used where mechanical clamps are undesirable.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Potential advantages include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Continuous support<\/li>\n\n\n\n<li>Simplified housing<\/li>\n\n\n\n<li>Sealing capability<\/li>\n\n\n\n<li>Reduced metal contact<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">However, adhesive systems must be carefully selected.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Consider:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u062f\u0631\u062c\u0629 \u062d\u0631\u0627\u0631\u0629 \u0627\u0644\u062a\u0634\u063a\u064a\u0644<\/li>\n\n\n\n<li>Cure shrinkage<\/li>\n\n\n\n<li>Elastic modulus<\/li>\n\n\n\n<li>Bond-line thickness<\/li>\n\n\n\n<li>Outgassing<\/li>\n\n\n\n<li>\u0645\u0642\u0627\u0648\u0645\u0629 \u0627\u0644\u0645\u0648\u0627\u062f \u0627\u0644\u0643\u064a\u0645\u064a\u0627\u0626\u064a\u0629<\/li>\n\n\n\n<li>Thermal expansion mismatch<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">For vacuum applications, adhesive outgassing must also be considered.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">22. Surface Quality Requirements<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Typical optical sapphire surface-quality specifications include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>80-50<\/li>\n\n\n\n<li>60-40<\/li>\n\n\n\n<li>40-20<\/li>\n\n\n\n<li>20-10<\/li>\n\n\n\n<li>10-5<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The correct requirement depends on the optical system.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For ordinary protective windows, specifying 10-5 may unnecessarily increase cost.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Higher quality becomes more important for:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u0644\u064a\u0632\u0631 \u0639\u0627\u0644\u064a \u0627\u0644\u0637\u0627\u0642\u0629<\/li>\n\n\n\n<li>Imaging<\/li>\n\n\n\n<li>Inspection optics<\/li>\n\n\n\n<li>\u0627\u0644\u0623\u062f\u0648\u0627\u062a \u0627\u0644\u0639\u0644\u0645\u064a\u0629<\/li>\n\n\n\n<li>Scattering-sensitive systems<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The clear aperture should also be stated together with the surface-quality requirement.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">23. AR Coating Considerations<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Uncoated sapphire surfaces reflect part of the incident light.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For systems requiring higher transmission, an anti-reflection coating may be applied.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Common design ranges include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u0627\u0644\u0623\u0634\u0639\u0629 \u0641\u0648\u0642 \u0627\u0644\u0628\u0646\u0641\u0633\u062c\u064a\u0629<\/li>\n\n\n\n<li>\u0645\u0631\u0626\u064a<\/li>\n\n\n\n<li>Near infrared<\/li>\n\n\n\n<li>Specific laser wavelengths<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u0648\u062a\u0634\u0645\u0644 \u0627\u0644\u0623\u0645\u062b\u0644\u0629 \u0639\u0644\u0649 \u0630\u0644\u0643:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">355 nm<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">532 nm<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">1064 nm<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">or broadband ranges such as:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">400-700 \u0646\u0627\u0646\u0648\u0645\u062a\u0631<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The RFQ should provide the actual operating wavelength rather than simply requesting:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u201cAR coating.\u201d<\/strong><\/p>\n\n\n\n<h1 class=\"wp-block-heading\">24. Typical Rectangular Sapphire Window Specification<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">A practical RFQ could look like this:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Material:<\/strong> Optical-grade single-crystal sapphire<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Shape:<\/strong> \u0645\u0633\u062a\u0637\u064a\u0644 \u0627\u0644\u0634\u0643\u0644<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Size:<\/strong> 50 \u00d7 30 mm<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u0627\u0644\u0633\u064f\u0645\u0643:<\/strong> 3 mm<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Corner radius:<\/strong> 4 \u00d7 R2 mm<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Edge:<\/strong> 0.3 \u00d7 45\u00b0 chamfer<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Surface:<\/strong> Double-side polished<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u062c\u0648\u062f\u0629 \u0627\u0644\u0633\u0637\u062d:<\/strong> 20-10<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Flatness:<\/strong> \u03bb\/4 @ 632.8 nm<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Parallelism:<\/strong> \u2264 3 arc min<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Clear aperture:<\/strong> \u2265 90%<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Coating:<\/strong> AR 400\u2013700 nm<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Quantity:<\/strong> 100 pcs<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is much more useful to a manufacturer than simply specifying:<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">50 \u00d7 30 \u00d7 3 mm sapphire glass.<\/p>\n<\/blockquote>\n\n\n\n<h1 class=\"wp-block-heading\">25. Rectangular Sapphire Window RFQ Checklist<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">When requesting a quotation, provide the following information.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u0627\u0644\u0623\u0628\u0639\u0627\u062f<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Length<\/li>\n\n\n\n<li>Width<\/li>\n\n\n\n<li>\u0627\u0644\u0633\u064f\u0645\u0643<\/li>\n\n\n\n<li>Dimensional tolerance<\/li>\n\n\n\n<li>Corner radius<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u0627\u0644\u062d\u0627\u0641\u0629<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Chamfer<\/li>\n\n\n\n<li>Bevel<\/li>\n\n\n\n<li>Radius<\/li>\n\n\n\n<li>Ground or polished edge<\/li>\n\n\n\n<li>Maximum allowable edge chip<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Optical<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u062c\u0648\u062f\u0629 \u0627\u0644\u0633\u0637\u062d<\/li>\n\n\n\n<li>\u0627\u0644\u062a\u0633\u0637\u064a\u062d<\/li>\n\n\n\n<li>\u0627\u0644\u062a\u0648\u0627\u0632\u064a<\/li>\n\n\n\n<li>\u062e\u0634\u0648\u0646\u0629 \u0627\u0644\u0633\u0637\u062d<\/li>\n\n\n\n<li>\u0627\u0644\u0641\u062a\u062d\u0629 \u0627\u0644\u0635\u0627\u0641\u064a\u0629<\/li>\n\n\n\n<li>Working wavelength<\/li>\n\n\n\n<li>AR coating<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u0627\u0644\u0645\u0648\u0627\u062f<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Sapphire grade<\/li>\n\n\n\n<li>Crystal orientation, if required<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Mechanical<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Unsupported aperture<\/li>\n\n\n\n<li>\u0641\u0631\u0642 \u0627\u0644\u0636\u063a\u0637<\/li>\n\n\n\n<li>\u0637\u0631\u064a\u0642\u0629 \u0627\u0644\u062a\u0631\u0643\u064a\u0628<\/li>\n\n\n\n<li>Housing material<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u0627\u0644\u0628\u064a\u0626\u0629<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u062f\u0631\u062c\u0629 \u062d\u0631\u0627\u0631\u0629 \u0627\u0644\u062a\u0634\u063a\u064a\u0644<\/li>\n\n\n\n<li>Thermal cycling<\/li>\n\n\n\n<li>\u0645\u0633\u062a\u0648\u0649 \u0627\u0644\u0641\u0631\u0627\u063a<\/li>\n\n\n\n<li>Process gas<\/li>\n\n\n\n<li>Chemical exposure<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Commercial<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Prototype quantity<\/li>\n\n\n\n<li>\u0643\u0645\u064a\u0629 \u0627\u0644\u0625\u0646\u062a\u0627\u062c<\/li>\n\n\n\n<li>Annual demand<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Providing these parameters early can significantly reduce design revisions and quotation uncertainty.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">26. Common Design Mistakes<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">Mistake 1: Specifying Perfectly Sharp Corners<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Unless required by the assembly, a small radius usually provides better manufacturability.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Mistake 2: Ignoring Edge Chips<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Edge defects can become critical under mechanical load.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Mistake 3: Maximizing Clear Aperture Without Considering Support<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A larger opening means less supported perimeter.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Mistake 4: Selecting Thickness Only From Outside Dimensions<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Unsupported span is often more important.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Mistake 5: Over-Specifying Flatness<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Tighter optical tolerances increase cost and should be justified by system requirements.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Mistake 6: Clamping the Window Directly Between Hard Metal Surfaces<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">This can create concentrated mounting stress.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Mistake 7: Ignoring Housing Flatness<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A warped mounting surface can bend the sapphire during installation.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">\u0627\u0644\u062e\u0627\u062a\u0645\u0629<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Rectangular sapphire windows provide an excellent combination of optical transparency, hardness, thermal resistance and environmental durability for demanding optical systems.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">However, their geometry requires more careful mechanical design than many simple circular windows.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The most important considerations include:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Corner radius + edge quality + unsupported span + thickness + flatness + mounting stress.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Sharp corners and damaged edges can create stress concentrations.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Excessive clear aperture can reduce mechanical support.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Poor housing flatness or uneven clamping can introduce stress even before the equipment begins operating.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For this reason, the best rectangular sapphire window specification should define not only length, width and thickness, but also:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Corner radius<\/li>\n\n\n\n<li>Edge condition<\/li>\n\n\n\n<li>\u0627\u0644\u0641\u062a\u062d\u0629 \u0627\u0644\u0635\u0627\u0641\u064a\u0629<\/li>\n\n\n\n<li>\u0627\u0644\u062a\u0633\u0637\u064a\u062d<\/li>\n\n\n\n<li>\u0627\u0644\u062a\u0648\u0627\u0632\u064a<\/li>\n\n\n\n<li>\u0637\u0631\u064a\u0642\u0629 \u0627\u0644\u062a\u0631\u0643\u064a\u0628<\/li>\n\n\n\n<li>Pressure<\/li>\n\n\n\n<li>\u062f\u0631\u062c\u0629 \u0627\u0644\u062d\u0631\u0627\u0631\u0629<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Designing the sapphire window together with its housing and operating environment usually provides better reliability than treating the optical component as an isolated plate.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u0627\u0644\u0623\u0633\u0626\u0644\u0629 \u0627\u0644\u0634\u0627\u0626\u0639\u0629<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Why do rectangular sapphire windows usually have rounded corners?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Rounded corners help improve manufacturability and can reduce local stress concentration compared with extremely sharp corners. The correct radius depends on the housing and optical clear-aperture requirements.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">What corner radius should I use for a rectangular sapphire window?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">There is no universal value. The radius should be selected based on window size, thickness, clear aperture, mounting structure and mechanical loading. If the design allows it, avoiding unnecessarily sharp corners generally improves manufacturing robustness.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Does a rectangular sapphire window need a chamfer?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A small chamfer is often useful because it removes fragile sharp edges and reduces handling damage. The required chamfer should be specified on the drawing.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">What determines the required sapphire window thickness?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Important factors include unsupported aperture, length-to-width ratio, pressure differential, mounting condition, temperature and required safety factor. Outside dimensions alone are not sufficient.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Can rectangular sapphire windows be AR coated?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Yes. Sapphire windows can be coated for UV, visible, NIR or specific laser wavelengths. The coating specification should include the actual operating wavelength or wavelength range.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Why can a sapphire window crack after installation?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Possible causes include edge damage, uneven clamping, point loading, housing distortion, excessive gasket compression and thermal expansion mismatch. The mounting system should therefore be evaluated together with the sapphire component.<\/p>","protected":false},"excerpt":{"rendered":"<p>Rectangular sapphire windows are widely used in optical sensors, industrial inspection systems, semiconductor equipment, laser systems, high-pressure instruments and harsh-environment viewing assemblies. Compared with circular sapphire windows, rectangular windows can make better use of available installation space and provide a larger usable field of view. However, their geometry also creates several additional engineering challenges. The [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":2841,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[17],"tags":[165,152,939,1181,1179,1180,164,1038,303,296,940],"class_list":["post-2840","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry-news","tag-custom-sapphire-window","tag-optical-sapphire-window","tag-rectangular-sapphire-window","tag-rectangular-sapphire-windows","tag-sapphire-corner-radius","tag-sapphire-edge-stress","tag-sapphire-optical-window","tag-sapphire-window-flatness","tag-sapphire-window-mounting","tag-sapphire-window-thickness","tag-square-sapphire-window"],"_links":{"self":[{"href":"https:\/\/www.sapphire-windows.com\/ar\/wp-json\/wp\/v2\/posts\/2840","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.sapphire-windows.com\/ar\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.sapphire-windows.com\/ar\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.sapphire-windows.com\/ar\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.sapphire-windows.com\/ar\/wp-json\/wp\/v2\/comments?post=2840"}],"version-history":[{"count":1,"href":"https:\/\/www.sapphire-windows.com\/ar\/wp-json\/wp\/v2\/posts\/2840\/revisions"}],"predecessor-version":[{"id":2842,"href":"https:\/\/www.sapphire-windows.com\/ar\/wp-json\/wp\/v2\/posts\/2840\/revisions\/2842"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.sapphire-windows.com\/ar\/wp-json\/wp\/v2\/media\/2841"}],"wp:attachment":[{"href":"https:\/\/www.sapphire-windows.com\/ar\/wp-json\/wp\/v2\/media?parent=2840"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.sapphire-windows.com\/ar\/wp-json\/wp\/v2\/categories?post=2840"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.sapphire-windows.com\/ar\/wp-json\/wp\/v2\/tags?post=2840"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}