Open AccessWaveguide tapering for improved parametric amplification in integrated nonlinear Si3N4 waveguides
Author(s) -
Ping Zhao,
Zhichao Ye,
Kovendhan Vijayan,
Corentin Naveau,
Jochen Schröder,
Magnus Karlsson,
Peter A. Andrekson
Publication year - 2020
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.389159
Subject(s) - tapering , optics , waveguide , parametric statistics , beam propagation method , materials science , optical parametric amplifier , wavelength , bandwidth (computing) , nonlinear system , nonlinear optics , optoelectronics , physics , optical amplifier , refractive index , telecommunications , computer science , laser , mathematics , statistics , computer graphics (images) , quantum mechanics
In this paper, we propose and numerically investigate waveguide tapering to improve optical parametric amplification in integrated nonlinear Si 3 N 4 circuits. The phase matching condition of parametric amplification changes along the length of uniform Si 3 N 4 waveguides, due to the non-negligible propagation loss, potentially causing peak-gain wavelength shifts of more than 20 nm. By tapering the waveguide width along propagation, we can achieve a 2.5 dB higher maximum parametric gain thanks to the improved phase matching, which can also broaden the amplification bandwidth. Therefore, the length of an optimally tapered Si 3 N 4 waveguide can be 23% shorter than a uniform one in the case of a 3.0 dB/m propagation loss and a single continuous-wavelength pump. Quasi-continuous tapers are efficient to approximate continuous ones and might simplify the fabrication of long tapered nonlinear Si 3 N 4 waveguides, which are promising for optical signal processing and optical communications.