Reflection / Transmission Spectrum Calculator & Color Simulator

Design and calculate the optical spectrum of multilayer coatings. Simulate the visual look. For example:

• Anti-reflection coating (ARC, AR coating);
• Optical filter (e.g., band-pass filter, notch filter, line filter);
• Visual color of coatings (e.g., anodized aluminum, SiO₂ on silicon);
• Appearance of 2D materials (e.g., graphene, MoS₂) on certain substrates (e.g., SiO₂/Si) under microscope with specified numerical aperture (NA).

Operation:

Toggle between Reflection / Transmission at the title banner;

Choose your Lighting condition such as incident angle;

Add material stack in Material Coating Stack and set layer thicknesses;

To check the data of an individual material, click the Plot button, or use Refractive Index section towards the end of the page;

Click Calculate Spectrum to do the calculation.

The visual color is simulated. To see the entire coating stack against some selected coating stack (e.g., the color of graphene against SiO₂/Si substrate), select the desired layers in corresponding check boxes.

Side note:

The program only calculates polarization dependency when the incident angle is not zero.

The absorption of light by the substrate does not affect transmission spectrum. The detector is assumed to be very close to the top of the substrate. If you would like to calculate the absorption of a thick glass, put it in the coating stack.

For microscope lighting condition, the axis of the objective lens (light cone) is assumed to be perpendicular to the substrate.

For microscope lighting condition, you can choose the intensity distribution:

Uniform (often seen in traditional light source) means the luminous intensity I does not depend on the incident angle;

Gaussian (often seen in single mode lasers) means the dependency is Gaussian, and the cut-off is set at e ^-2.