Optical Filter Thickness Variability

The thickness of an optical filter is not solely determined by its final optical properties, but can vary based on several factors:

Coating Design

Different designs can achieve similar optical properties with varying thicknesses

Multiple layers of different materials may be used

Layer thicknesses can range from thin to thick (10+ quarter-wave optical thickness)

Substrate Influence

Substrate material affects overall performance

Refractive index of substrate impacts coating requirements

Wavelength Considerations

Shorter wavelengths typically require thinner layers

Physical thickness of quarter-wave optical thickness (QWOT) varies with target wavelength

Performance Requirements

Specific optical properties influence design and thickness

High absorption in certain wavelengths may necessitate thicker coatings

Conslusion 

while optical filters may have the same final result, their thickness can vary significantly depending on the coating design, substrate, and specific application requirements.