Open AccessNonlinear properties of laser-processed polycrystalline silicon waveguides for integrated photonics
Author(s) -
Ozan Aktaş,
Stuart James MacFarquhar,
Swe Zin Oo,
Antulio Tarazona,
Harold M. H. Chong,
Anna C. Peacock
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.400536
Subject(s) - materials science , silicon , optics , silicon photonics , polycrystalline silicon , photonics , laser , optoelectronics , amorphous silicon , attenuation coefficient , kerr effect , nonlinear system , crystalline silicon , nanotechnology , physics , layer (electronics) , quantum mechanics , thin film transistor
We report nonlinear optical characterization of cm-long polycrystalline silicon (poly-Si) waveguides at telecom wavelengths. Laser post-processing of lithographically-patterned amorphous silicon deposited on silica-on-silicon substrates provides low-loss poly-Si waveguides with surface-tension-shaped boundaries. Achieving optical losses as low as 4 dB cm -1 enabled us to demonstrate effects of self-phase modulation (SPM) and two-photon absorption (TPA). Analysis of the spectral broadening and nonlinear losses with numerical modeling reveals the best fit values of the Kerr coefficient n2=4.5×10 -18 m W -1 and TPA coefficient βTPA=9.0×10 -12 m 2 W -1 , which are within the range reported for crystalline silicon. On-chip low-loss poly-Si paves the way for flexible integration of nonlinear components in multi-layered photonic systems.