Conformal antireflection coatings for optical dome covers by atomic layer deposition

Area of Science:

• Materials Science
• Optical Engineering
• Thin Film Technology

Background:

• Conventional coating technologies struggle with complex 3D-shaped optics.
• Large dome-shaped optics require advanced functionalization for optical performance.

Purpose of the Study:

• To demonstrate a scalable atomic layer deposition (ALD) method for applying conformal antireflection (AR) coatings on large, 3D-shaped optical components.
• To simulate and test AR coatings on large dome-shaped optics using functionalized glass cubes.

Main Methods:

• Utilized large, top-open optical glass cubes (100 mm side length) as demonstrators for dome-shaped optics.
• Applied broadband (420-670 nm) and narrowband (550 nm) AR coatings using ALD.
• Performed reflectance measurements on both inner and outer surfaces of the coated cubes.

Main Results:

• Achieved conformal AR coatings on the complex surfaces of the glass cubes.
• Demonstrated significantly low residual reflectance: below 0.3% for visible wavelengths and 0.2% for single wavelengths.
• Confirmed coating uniformity across nearly the entire surface of the demonstrators.

Conclusions:

• ALD is a viable technique for coating large, complex 3D-shaped optics with high uniformity and low reflectance.
• The developed method successfully simulates and validates AR coatings for dome-shaped optical systems.
• This advancement has implications for various optical applications requiring high-performance coatings on non-conventional geometries.