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Silicon nanocrystals for nonlinear optics and secure communications
Author(s) -
Bisadi Z.,
Mancinelli M.,
Manna S.,
Tondini S.,
Bernard M.,
Samusenko A.,
Ghulinyan M.,
Fontana G.,
Bettotti P.,
RamiroManzano F.,
Pucker G.,
Pavesi L.
Publication year - 2015
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201532528
Subject(s) - materials science , optoelectronics , waveguide , optics , resonator , silicon , whispering gallery wave , silicon photonics , photonics , physics
Silicon nanocrystals (Si‐nc) are reviewed here for their interesting optical applications. On the one hand, they do exhibit quantum confinement effects. This allows turning silicon into a light‐emitting material where luminescence can be excited by electrical injection. On the other hand, small sizes, large surfaces, and dielectric mismatch between the core and the surrounding matrix increase dramatically the nonlinear optical coefficients. This allows using Si‐nc as a nonlinear material in different waveguide configurations. In this paper, we discuss specifically two different applications of Si‐nc: (i) as a nonlinear material in various devices, e.g., in bistable optical cavities, in waveguide optical mode monitors that are based on two‐photon excited luminescence detection, and in wavelength shifters by using four‐wave mixing (FWM); (ii) as an entropy source for quantum random number generation, the key device for cryptography. (a) Top view optical image of a Si‐nc‐based whispering‐gallery mode (WGM) microdisk resonator, vertically coupled with a bus waveguide. (b) Detail of the coupling zone. (c) Normalized waveguide transmission spectrum over a wide spectral range. The inset shows a blow up of a resonance with the radial and azimuthal mode orders and the Q factor value indicated.