Realizing highly efficient vertical coupling with dielectric deflective metasurfaces.
Opt Lett
; 49(11): 3182-3185, 2024 Jun 01.
Article
in En
| MEDLINE
| ID: mdl-38824358
ABSTRACT
Using dielectric deflective metasurfaces, we propose a novel, to the best of our knowledge, out-of-plane modulation scheme to realize vertical coupling on a 220â
nm silicon-on-insulator platform. The metasurface is used to deflect vertical incident light to an oblique angle with high efficiency in the cladding layer. This deflection introduces a lateral wave vector component, thus preventing bi-directional transmission of traditional vertical coupling due to the second-order Bragg reflection of the grating. Additionally, an apodized design is employed for the subwavelength grating to improve mode matching with a deflection angle incident. The integration of the metasurface and subwavelength grating enables a new vertical coupling scheme with high efficiency. After global optimization, we achieved a simulation coupling efficiency of -2.19â
dB. The measured coupling efficiency is -3.36â
dB with a center wavelength of 1545.6â
nm and a 1-dB bandwidth of 32â
nm. The results confirm the feasibility of the proposed new architecture.
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01-internacional
Database:
MEDLINE
Language:
En
Journal:
Opt Lett
Year:
2024
Document type:
Article
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