Development of Wide-Angle Depolarizing Reflector at 1064 nm

Area of Science:

• Optics
• Materials Science
• Biomedical Imaging

Background:

• Optical coherence tomography (OCT) is a non-contact, high-resolution imaging technique vital for biological tissue analysis.
• Wide-angle depolarizing reflectors are critical optical components for accurate signal acquisition in OCT systems.

Purpose of the Study:

• To design and fabricate a wide-angle depolarizing reflective film for OCT systems operating at 1064 nm.
• To meet the stringent optical parameter requirements for enhanced OCT performance.

Main Methods:

• Utilized Ta2O5 and SiO2 as coating materials based on system requirements.
• Employed thin-film optics theory, MATLAB, and OptiLayer software for film design.
• Optimized deposition using optical thermal co-circuit interferometry and implemented a "crystal control + optical control" strategy for precise thickness management.

Main Results:

• Achieved a depolarizing reflective film for 0° to 60° incident angles at 1064 ± 40 nm.
• Demonstrated average reflectance exceeding 99.5% with P-light and S-light deviation below 1%.
• Ensured a film layer thickness error of less than 1% through advanced monitoring schemes.

Conclusions:

• The developed wide-angle depolarizing reflector meets the demanding requirements of OCT systems.
• The precise fabrication method ensures high performance for biological tissue imaging applications.
• This advancement contributes to improved accuracy and reliability in OCT-based diagnostics.