Dual-polarization silicon nitride Bragg filters with low thermal sensitivity

Elena Duran-Valdeiglesias (1) , Sylvain Guerber (2) , Dorian Oser (1) , Xavier Le Roux (1) , Daniel Benedikovic (1) , Diego Perez-Galacho (1) , Nathalie Vulliet (3) , Sébastien Cremer (3) , Stéphane Monfray (3) , Eric Cassan (1) , Delphine Marris-Morini (4) , Charles Baudot (3) , Frédéric Boeuf (3) , Laurent Vivien (1) , Carlos Alonso-Ramos (1)

1 C2N - Centre de Nanosciences et de Nanotechnologies [Orsay]
2 C2N - Centre de Nanosciences et de Nanotechnologies [Marcoussis]
3 ST-CROLLES - STMicroelectronics [Crolles]
4 IEF - Institut d'électronique fondamentale

Wideband and polarization-independent wavelength filters with low sensitivity to temperature variations have great potential for wavelength division multiplexing applications. However, simultaneously achieving these metrics is challenging for silicon-on-insulator photonics technology. Here, we harness the reduced index contrast and the low thermo-optic coefficient of silicon nitride to demonstrate waveguide Bragg grating filters with wideband apolar rejection and low thermal sensitivity. Filter birefringence is reduced by judicious design of a triangularly shaped lateral corrugation. Based on this approach, we demonstrate silicon nitride Bragg filters with a measured polarization-independent 40 dB optical rejection with negligible off-band excess loss, and a sensitivity to thermal variations below 20 pm/°C.

Mots clés: OCIS codes: (1303120) Integrated optics devices; (2307390) Waveg- uides; planar; (2301480) Bragg reflector; (0406040) Silicon

Domaines: Optique / photonique

Elena Duran-Valdeiglesias, Sylvain Guerber, Dorian Oser, Xavier Le Roux, Daniel Benedikovic, et al.. Dual-polarization silicon nitride Bragg filters with low thermal sensitivity. Optics Letters, 2019, 44 (18), pp.4578. ⟨10.1364/OL.44.004578⟩. ⟨hal-02413918⟩