Open AccessInvestigation of mid-infrared second harmonic generation in strained germanium waveguides
Author(s) -
Francesco De Leonardis,
Benedetto Troia,
Richard A. Soref,
Vittorio M. N. Passaro
Publication year - 2016
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.24.011126
Subject(s) - germanium , materials science , second harmonic generation , cladding (metalworking) , optics , optoelectronics , infrared , wavelength , nonlinear optics , multiphysics , laser , silicon , physics , finite element method , metallurgy , thermodynamics
In this paper we present a detailed theoretical investigation of second harmonic generation in strained germanium waveguides operating at the mid infrared pump wavelength of 4 μm. The effective second order susceptibility has been estimated through a multiphysics approach considering the residual stress of the SiN x cladding film. Furthermore, general physical features have been investigated by means of a comparative analysis of SHG performance as a function of input pump power, linear and nonlinear phase mismatching, effective recombination carrier lifetime, and temperature, taking into account both continuous and pulsed regimes. Finally, periodically poled germanium devices have been explored with the aim to improve the SHG efficiency. In the same operative conditions, efficiencies of 0.6% and 0.0018% have been obtained in poled and not-poled waveguides, respectively.