Loading [MathJax]/extensions/TeX/color.js
eo_logo
 
Product added to cart

 
Coating Impact on Flatness Calculator

View All Technical Tools

Surface Flatness Before Coating, SF1:

Wavelength for Flatness Specification (nm):

Substrate Thickness, ts (mm):

Substrate Diameter, D (mm):

Substrate Material:

Coating Type:

Coating Technology Used:

Surface Flatness After Coating (PV), SF2: --     

Percentage Change in Surface Flatness: --     

Note: Assumes coating on one side only

Coating Impact on Flatness Calculator

Equations and Corresponding Legend: $$ R = \frac{1}{6} \left( \frac{\left( \frac{E_s \times t_s ^3}{1 - v_s} \right ) + \left( \frac{E_c \times t_c ^3}{1 - v_c} \right )}{\sigma \times t_c \times \left( t_c + t_s \right )} \right )$$ $$ \text{SF}_2 = \text{SF}_1 \left[\text{waves} \right] \times \frac{\text{SF}_1 \left[ \large{ \unicode[Cambria Math]{x03BC}} \normalsize{\text{m} } \right ]}{\text{SF}_1 \left[ \large{ \unicode[Cambria Math]{x03BC}} \normalsize{\text{m} } \right ] + \frac{D^2}{8R}}$$ $$ \% \text{Change} = 100 \% \times \left | \frac{\text{SF}_1 - \text{SF}_2}{\text{SF}_1} \right | $$

R Radius of Curvature [µm]
D Substrate Diameter [µm]
Es Substrate Elasticity Modulus [Pa]
Ec Coating Elasticity Modulus [Pa]
ts Substrate Thickness [µm]
tc Coating Thickness [µm]
vs Substrate Poisson’s Ratio (unitless)
vc Coating Poisson’s Ratio (unitless)
σ Coating Stress (MPa)
SF1 Surface Flatness Before Coating (waves or µm)
SF2 Surface Flatness After Coating (waves or µm)

The calculator is based on the following assumptions:

  • Mechanical properties of coating materials are averaged from the bulk values
  • Coating stress for a particular coating technology is approximated from historical data
  • Stress-induced deformation is assumed to be spherical
  • It is assumed that R >> D

Description

Many modern-day optical coating technologies, such as magnetron sputtering and ion beam sputtering, involve high-energy material deposition. While these techniques can create coatings with distinct advantages, they can impart a significant amount of stress on the coating and substrate. This stress can lead to issues with surface flatness, impacting the transmitted or reflected wavefront error of coated optics.

This calculator approximates the impact of coating-induced stress on the surface flatness of a coated optic.

Related Resources and Capabilities

 Application Note
An Introduction to Optical Coatings
An Introduction to Optical Coatings

 Application Note
Anti-Reflection (AR) Coatings
Anti-Reflection (AR) Coatings

 Application Note
Highly Reflective Coatings
Highly Reflective Coatings

 Application Note
The Complexities of High-Power Optical Coatings
The Complexities of High-Power Optical Coatings
 Published Article
Optical Coatings Technology
"Optical Coatings Technology" by Chris Cook and Cory Boone - Tech Briefs

 Published Article
No One-Size-Fits-All Approach to Selecting Optical Coatings
"No One-Size-Fits-All Approach to Selecting Optical Coatings" by Stefaan Vandendriessche - Photonics Media
 Webinar
High Reflectivity Mirrors for Laser Applications
High Reflectivity Mirrors for Laser Applications

 Video
EO Global Manufacturing Facilities
EO Global Manufacturing Facilities


 Capabilities
Optical Coating Capabilities
Optical Coating Capabilities

 
Sales & Expert Advice
 
or view regional numbers
 Live Chat
Easy-to-Use
QUOTE TOOL
enter stock numbers to begin
Sign-up Today | Industry trends, new products, discounts, and technical content  Sign-up
About Us About UsTradeshows Regional Offices Careers Press Releases Case Studies Compliance TECHSPEC®Brand Partnerships
Customer Care ShippingReturnsFAQsGive Feedback Manufacturing Services Precision Optics Filter Optics Laser Optics Imaging Optics
Discounts & Programs All Discount Programs Vision Integration Partners Volume Discount ServicesEducational Discount Program Educational Award Discounted Products Edmund Scientific Outreach E-procurement Platforms
Catalogs All Catalogs Digital Catalogs Catalog Preferences

Copyright 2023, Edmund Optics Inc., 14F., No.83, Sec. 4, Wenxin Road, Beitun District , Taichung City 406, Taiwan (R.O.C.)

Privacy Policy | Cookie Policy | Terms & Conditions | Accessibility
California Consumer Privacy Act (CCPA): Do Not Sell My Information