Focus on Special Features

• Optimization Overview
• Needle Optimization
• Needle/Tunneling Optimization
• Electric Field Intensity
• Sensitivity to Manufacturing Errors
• Layer Sensitivity
• Color Sensitivity
• Biconical Transmittance
• Optical Monitoring
• Determining Refractive Index (N and K)
• Sources of Material Data

Color Sensitivity

For broadband coatings in the visible part of the spectrum (wavelengths 380 to 780 nm), the color of reflected and/or transmitted light may be important. As an example, consider anti-reflection coatings for eye glasses, which usually have a green reflection. A four-layer coating can reduce the luminous reflectance to 0.1% and have a reflected color of x=0.3, y=0.4. However, as the plot below shows, if we have even a small manufacturing error, the color of the reflected light varies considerably.

In this type of coating, the reflected color is often more important than the reflectance. Hence, we may be able to tradeoff reflectance for more color stability. By using TFCalc’s capability of optimizing sensitivity, the color sensitivity can be controlled, as shown below.