Ultralong waveguide grating antenna enabled by evanescent field modulation.
Opt Lett
; 47(20): 5397-5400, 2022 Oct 15.
Article
en En
| MEDLINE
| ID: mdl-36240373
ABSTRACT
Waveguide grating antenna (WGA) is a key component for an on-chip optical phased array. In order to form a beam with a small divergence angle, WGAs of several millimeters in length are highly desired. However, in high-index-contrast platforms such as silicon-on-insulator (SOI), such long WGAs typically require weakly modulated gratings with critical feature sizes below 10â
nm. In this paper, we experimentally demonstrate a new, to the best of our knowledge, strategy to implement long WGAs. Instead of directly modulating a waveguide, we propose periodically modulating the evanescent field with subwavelength blocks. With this arrangement, weak grating strength can be achieved while maintaining a minimum feature size as large as 100â
nm. For proof-of-concept, we experimentally demonstrate a 1-mm-long, single-etched WGA on a conventional 220â
nm SOI platform, which achieves a far-field divergence angle of 0.095° and a wavelength scanning sensitivity of 0.168°/nm.
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MEDLINE
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En
Revista:
Opt Lett
Año:
2022
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Article