Comparative study of NIR-MIR beamsplitters based on ZnS/YbF₃ and Ge/YbF₃

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Beamsplitters are crucial optical components for spectral separation.
• Developing efficient beamsplitters for broad spectral ranges, particularly near-infrared (NIR) and mid-infrared (MIR), remains an active research area.

Purpose of the Study:

• To design, produce, and characterize novel thin-film beamsplitters for NIR (770-1050 nm) and MIR (4-8 µm) spectral ranges.
• To investigate the potential of ZnS/YbF₃ and Ge/YbF₃ material combinations for dichroic coatings operating at the Brewster angle of a ZnSe substrate.

Main Methods:

• Thin-film multilayer deposition and characterization.
• Optical performance analysis including reflectance and bandwidth.
• Non-optical characterization of thin-film properties.

Main Results:

• ZnS/YbF₃ thin films provide high reflectance in the NIR range.
• Ge/YbF₃ thin films demonstrate very broadband reflection zones.
• Ge/YbF₃ coatings are thinner and require fewer layers compared to ZnS/YbF₃ multilayers.

Conclusions:

• Both ZnS/YbF₃ and Ge/YbF₃ material combinations show potential for NIR-MIR beamsplitter applications.
• The Ge/YbF₃ pair is particularly promising due to its broadband performance, thinner structure, and fewer layers, indicating high potential for NIR-MIR coating design and production.