Open AccessEvanescent-wave coupling phase-matching for ultrawidely tunable frequency conversion in silicon-waveguide chips
Author(s) -
Yingwen Liu,
Chao Wu,
Xiaogang Qiang,
Junjie Wu,
Xuejun Yang,
Ping Xu
Publication year - 2019
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.27.028866
Subject(s) - optics , waveguide , physics , bandwidth (computing) , coupled mode theory , coupling (piping) , photonics , four wave mixing , broadband , silicon photonics , nonlinear optics , quantum optics , photon , optoelectronics , materials science , refractive index , computer science , telecommunications , laser , metallurgy
We propose and analyze an evanescent-wave coupling phase-matching method for ultrawidely tunable frequency conversion in coupled χ (3) -waveguides which will boost the nonlinear optical properties of photonic chips. Taking a silicon-waveguide as an example, we design a two-coupled-waveguide system which provides an efficient coupling coefficient for the compensation of phase-mismatch in spontaneous four-wave mixing, achieving widely tunable entangled photon pairs which are usually not accessible in χ (3) -waveguides. A tuning range of 1170-2300 n m for TE-mode or 1400-1730 n m for TM-mode entangled photons is realized when the inter-waveguide gap varies within the range of 400-900 n m . The bandwidth of evanescent-wave coupling phase-matching is also characterized. This unique phase-matching strategy is in principle applicable to any χ (2) - and χ (3) -waveguide chip, qualifying them as broadband frequency converters which will have wide applications in nonlinear optics and quantum optics.