1. Physical Vapor Deposition (PVD)

1.1 Electron Beam Evaporation (E-Beam Evaporation)

• Principle: An electron beam heats and vaporizes coating materials; vapor atoms condense layer by layer on optical substrates.

• Features: Low cost, mature process, flexible for multi-layer film design.

• Application: General AR coatings, lens coatings, conventional reflective coatings.

1.2 Sputtering

• Principle: High-energy ion bombardment knocks atoms off a target material, which deposit onto the substrate.

• Features: Denser film structure, higher hardness, excellent laser damage resistance, stable environmental performance.

• Application: High-power laser coatings, precision optical filters, aerospace-grade optics.

2. Chemical Vapor Deposition (CVD)

• Principle: Reactive gas mixtures react chemically in a vacuum chamber to form solid thin films on the substrate surface.

• Features: Uniform thickness, strong adhesion, suitable for special hard coatings.

• Application: Infrared optical coatings, diamond-like carbon (DLC) coatings, harsh environment optics.

3. Thermal Evaporation

• Principle: Resistance heating melts and evaporates coating materials.

• Features: Simple equipment, low cost, but lower film density and stability.

• Application: Low-demand consumer optical components, basic reflective films.

4. Sol-Gel Coating

• Principle: Liquid chemical solution is coated on substrate, then cured to form a thin film.

• Features: Low temperature, low cost, suitable for large-aperture optics.

• Application: Large window anti-reflection coatings, astronomical optics.

5. Ion-Assisted Deposition (IAD)

• Principle: Add ion beam bombardment during evaporation deposition.

• Features: Improve film density, reduce stress, enhance durability and spectral stability.

• Application: High-precision imaging optics, broadband AR coatings, outdoor environmental-resistant coatings。