Presentation
5 April 2018 Advanced solutions in silicon photonics using traditional fabrication methods and materials of CMOS technologies (Conference Presentation)
Charles Baudot, Maurin Douix, Sylvain Guerber, Sébastien Crémer, Nathalie Vulliet, Jonathan Planchot, Romuald Blanc, Laurène Babaud, Carlos Alonso-Ramos, Diego Pérez-Galacho, Sonia Messaoudène, Sébastien Kerdiles, Daniel Benedikovic, Catherine Euvard-Colnat, Eric Cassan, Delphine Marris-Morini, Laurent Vivien, Pablo Acosta-Alba, Frédéric Boeuf
Author Affiliations +
Proceedings Volume 10537, Silicon Photonics XIII; 105370G (2018) https://doi.org/10.1117/12.2290252
Event: SPIE OPTO, 2018, San Francisco, California, United States
Abstract
Optical signal modulation is presently done using Si pn junctions which cause phase shifting due to Soref effect and, put in a Mach-Zehnder configuration, produce interference and generate amplitude modulation. The drawback of pn junctions is the relatively low phase shifting efficiency which consequently inflicts high power consumptions on the electrical driver. An alternative device to pn junctions was developed and consists of introducing capacitive structures within the optical waveguide. The proposed device has the same cross-section foot-print but is much shorter due to improved efficiencies. Typical pn-junctions can generate phase shifts of < 20°/mm for given implantation conditions and the capacitive structure developed produces shifts of > 60°/mm for the same implantation conditions. The device is made up of crystal Si, a thin SiO2 capacitor dielectric and poly-Si. Benchmarking the two phase shifters with respect to insertion losses, we observe that the proposed device is promising. Another material exhaustively used in CMOS technologies is Si3N4. In the data-communication bandwidths, the index contrast between Si3N4 (n = 1.95) and SiO2 (n=1.45) is smaller than that with Si (n = 3.5). Thus, nitride waveguides have lower optical mode confinements and are thus less sensitive to insertion losses caused by line edge roughness and wavelength shifting incurred by process variations. Moreover, the temperature induced index variations are 5 times les in Si3N4 than Si. Therefore, the use of nitride to fabricate devices in silicon photonics looks advantageous. However, high speed electro-optic devices are challenging in Si3N4. Consequently, a co-integration of both materials is essential. We developed a fabrication method and associated devices which allow to transfer the signal to and fro Si and Si3N4. We present some devices in each layer to illustrate the benefits.
Conference Presentation
© (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Charles Baudot, Maurin Douix, Sylvain Guerber, Sébastien Crémer, Nathalie Vulliet, Jonathan Planchot, Romuald Blanc, Laurène Babaud, Carlos Alonso-Ramos, Diego Pérez-Galacho, Sonia Messaoudène, Sébastien Kerdiles, Daniel Benedikovic, Catherine Euvard-Colnat, Eric Cassan, Delphine Marris-Morini, Laurent Vivien, Pablo Acosta-Alba, and Frédéric Boeuf "Advanced solutions in silicon photonics using traditional fabrication methods and materials of CMOS technologies (Conference Presentation)", Proc. SPIE 10537, Silicon Photonics XIII, 105370G (5 April 2018); https://doi.org/10.1117/12.2290252
Advertisement
Advertisement
KEYWORDS
Silicon

Silicon photonics

CMOS technology

Phase shifting

Phase shifts

Silica

Waveguides

Back to Top