Resonant Coupling for Active-Passive Monolithic Integration of Al 2 O 3 and Si 3 N 4

Jinfeng Mu*, Meindert Dijkstra, Sonia M. García-Blanco

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

8 Citations (Scopus)
23 Downloads (Pure)


The developed double-layer Al 2 O 3 -Si 3 N 4 photonic platform monolithically combines the outstanding optical features of LPCVD Si 3 N 4 and the properties of rare-earth-ion-doped Al 2 O 3 active material. In this letter, a resonant coupling is studied in Al 2 O 3 -Si 3 N 4 couplers by introducing a lateral shift between a lateral Al 2 O 3 taper and a vertical Si 3 N 4 taper. The proposed resonant couplers enable to reduce mode mismatch losses at the taper tips, avoiding submicrometer lithography process while yielding a broadband and fabrication-tolerant performance. Undoped Al 2 O 3 -Si 3 N 4 resonant couplers are fabricated, with measured total losses less than 0.18 dB in the 1460-1635-nm spectral window. The first demonstration of active-passive integration is carried out using resonant couplers between Al 2 O 3 :Er 3+ and Si 3 N 4 waveguides, showing the great potential of our double-layer Al 2 O 3 -Si 3 N 4 platform for the realization of active-passive-integrated functionalities in the Si 3 N 4 technology.

Original languageEnglish
Article number8674816
Pages (from-to)771-774
Number of pages4
JournalIEEE photonics technology letters
Issue number10
Publication statusPublished - 15 May 2019


  • active-passive integration
  • monolithic integration
  • optical coupler
  • Resonant coupling
  • waveguide taper
  • 22/4 OA procedure

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