Design of an Integrated Circularly Polarized HgCdTe Photodetector Based on Silicon Metasurfaces

Compared with conventional detectors, a circularly polarized detector operating at 4.26 μm effectively suppresses background noise (e.g., solar scattering and atmospheric interference), enabling high-precision CO<sub>2</sub> monitoring across ecosystems like farmland, forests, and wetlan...

Full description

Saved in:
Bibliographic Details
Main Authors: Bo Cheng, Yuxiao Zou, Zihui Ge, Hanxiao Shao, Kunpeng Zhai, Guofeng Song
Format: Article
Language:English
Published: MDPI AG 2025-05-01
Series:Photonics
Subjects:
Online Access:https://www.mdpi.com/2304-6732/12/5/519
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Compared with conventional detectors, a circularly polarized detector operating at 4.26 μm effectively suppresses background noise (e.g., solar scattering and atmospheric interference), enabling high-precision CO<sub>2</sub> monitoring across ecosystems like farmland, forests, and wetlands. This capability allows the precise quantification of carbon sink potential and ecosystem health. Our design employs a mid-wave HgCdTe detector—a well-established platform—combined with a CMOS-compatible Si/SiO<sub>2</sub> metasurface. Geometric displacements were applied to break C<sub>2</sub> symmetry, achieving a chiral design. Through multiparameter optimization, we realized a circularly polarized photodetector (CPPD) with a CPER of 18 dB, expected to demonstrate superior CO<sub>2</sub> monitoring performance. These advances may offer researchers and practitioners a robust tool for both fundamental studies and field deployments.
ISSN:2304-6732