Multi-band terahertz resonant absorption based on an all-dielectric grating metasurface for chlorpyrifos sensing.
Opt Express
; 29(9): 13563-13575, 2021 Apr 26.
Article
in En
| MEDLINE
| ID: mdl-33985089
ABSTRACT
Perfect metasurface absorbers play a significant role in imaging, detecting, and manipulating terahertz radiation. We utilize all-dielectric gratings to demonstrate tunable multi-band absorption in the terahertz region. Simulation reveals quad-band and tri-band absorption from 0.2 to 2.5 THz for different grating depths. Coupled-mode theory can explain the absorption phenomenon. The absorption amplitude can be precisely controlled by changing the pump beam fluence. Furthermore, the resonant frequency is sensitive to the medium's refractive index, suggesting the absorber may be of great potential in the sensor detection field. The experimental results exhibit a high detectivity of pesticides.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Opt Express
Journal subject:
OFTALMOLOGIA
Year:
2021
Document type:
Article