Polarization-insensitive subwavelength grating reflector based on a semiconductor-insulator-metal structure

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Subwavelength gratings offer unique optical properties.
• Achieving polarization-insensitivity in optical reflectors is challenging.
• Semiconductor-insulator-metal structures are promising for optical devices.

Purpose of the Study:

• To design and demonstrate a polarization-insensitive subwavelength grating reflector.
• To investigate the optical characteristics of a novel semiconductor-insulator-metal structure.
• To achieve high reflectivity over a broad bandwidth for both TE and TM polarizations.

Main Methods:

• Fabrication of a subwavelength grating reflector using a semiconductor-insulator-metal structure.
• Optical characterization of the grating reflector's performance.
• Analysis of the polarization-dependent reflectivity using optical simulations.

Main Results:

• Demonstrated a polarization-insensitive subwavelength grating reflector.
• Achieved overlapped high reflectivity (>99.5%) bandwidth of 89 nm for TE and TM polarizations.
• The device utilizes a hybrid grating approach combining high-index-contrast and metallic gratings.

Conclusions:

• The proposed structure effectively suppresses polarization dependence in subwavelength grating reflectors.
• The developed reflector is suitable for applications requiring polarization-independent optical performance.
• This work contributes to the advancement of optical components for diverse photonic systems.