Optical Filter Thickness Uniformity Insights

Importance of Thickness Uniformity

Optical filters rely on uniform film thickness to ensure consistent spectral performance. Variations in thickness across the substrate can degrade filter characteristics, impacting applications like spectroscopy and imaging.

Anti-Reflection Coatings

For single-layer MgF2 anti-reflection coatings (thickness λ0/4, e.g., 130nm at λ0=520nm), thickness variation should typically not exceed 4nm to avoid color inconsistencies across the substrate.

Narrowband Filters

Narrowband filters require stringent uniformity. Variations must keep peak wavelength shifts below 0.3 times the FWHM (e.g., 6nm for a 20nm FWHM filter with a 50mm diameter). Larger or narrower filters demand even tighter control.

Cutoff Filters

High-steepness cutoff filters need uniform thickness to maintain sharp transitions. Poor uniformity can broaden the transition zone, reducing performance in applications like fluorescence microscopy.

Why Choose MOVO OPTO?

MOVO OPTO delivers high-precision optical filters with superior thickness uniformity for UV, VIS, NIR, IR, and fluorescence applications. Explore our custom optical filters at www.optofilters.com, meeting global standards.