Wavelength-assignable 1310/1550 nm wavelength conversion using
completely phase-matched two-pump four-wave mixing in a silicon
waveguide
Jian Chen, Shiming Gao
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Centre for Optical and Electromagnetic Research, State Key Laboratory of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310058, China
article info
Article history:
Received 6 February 2015
Received in revised form
6 August 2015
Accepted 7 August 2015
Keywords:
Four-wave mixing
Silicon waveguide
Optical communications
Wavelength conversion
PACS:
42.65.Wi
42.79.Nv
abstract
A wavelength converter between 1310 and 1550 nm bands is presented based on two-pump four-wave
mixing (FWM) in a silicon waveguide. The principle of the inter-band wavelength conversion is analyzed.
For an arbitrary incident signal, the converted idler wavelength can be freely assigned by suitably setting
the two pump wavelengths to completely satisfy the phase-matching condition. Simulation results show
that the signal can be flexibly converted between 1310 and 1550 bands. The conversion efficiencies for
the signals with different wavelengths are very stable because the FWM phase-matching condition is
completely met. Using this two-pump FWM configuration, channel-selective function can also be rea-
lized for wavelength division multiplexing (WDM) signals by engineering the dispersion profile of the
silicon waveguide according to the WDM channel spacing.
& 2015 Elsevier B.V. All rights reserved.
1. Introduction
Wavelength conversion is one of the essential all-optical signal
processing operations in next generation wavelength-routing op-
tical communication networks. Since a number of access-metro
schemes utilizing simultaneously 1310 and 1550 nm transmission
windows have been proposed [1], the data stream has to be
translated all-optically between 1310 and 1550 nm wavelength
domains to ensure the system functions. This kind of inter-band
wavelength conversion has attracted considerable attentions and
the challenge is that the wavelength difference is quite large,
which is more than 200 nm. Some methods have been developed
to solve this problem. 1310 nm signals have been converted to
1550 nm using nonlinear polarization rotation in semiconductor
optical amplifiers (SOAs) [2] or using cross-absorption modulation
in 1550 nm electroabsorption modulators (EAMs) [3]. However,
the duplex function cannot be realized using these schemes and
1550 nm signals can not be converted to 1310 nm simultaneously.
Four-wave mixing (FWM) is widely considered as a promising
solution to wavelength conversion due to its high speed and strict
transparency. Moreover, FWM-based wavelength conversion can
solve the duplex problem due to the inherent characteristics. In
particular, nondegenerate FWM using two pumps shows more
flexibility in phase matching and has more possibility to acquire
broad conversion bandwidth, which refers to the wavelength re-
gion whose conversion efficiency drops less than 3 dB. Two-pump
FWM has been well investigated in optical fibers to realize wa-
velength exchange [4,5] and wavelength conversion with channel
selection [6], with low noise [7], or with large wavelength shift [8].
Above contributions mainly focused on the 1550 nm band. A wa-
velength converter from 1550 nm to 1310 nm has also been pre-
sented using two-pump FWM in a highly nonlinear photonic
crystal fiber [9].
Recently, silicon emerges as an exciting FWM medium for in-
tegrated wavelength conversion due to its strong light confine-
ment and high nonlinear coefficient. Silicon-based wavelength
conversion overcomes the shortcoming of large volume in optical
fibers and has the potential to realize ultra-high integration. For
the wavelength conversion using FWM in silicon waveguides, the
difficulty is still the realization of a conversion bandwidth more
than 200 nm. Generally, there are two ways to enhance the con-
version bandwidth. One effective way is to engineer the dispersion
of the silicon waveguide by optimizing the waveguide geometries
[10–16] or designing waveguide structures [17–20]. Some opti-
mizations of waveguide geometries have been reported and the
bandwidth has been enhanced up to more than 200 nm
Contents lists available at ScienceDirect
journal homepage: www.elsevier.com/locate/optcom
Optics Communications
http://dx.doi.org/10.1016/j.optcom.2015.08.014
0030-4018/& 2015 Elsevier B.V. All rights reserved.
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Corresponding author.
E-mail address: gaosm@zju.edu.cn (S. Gao).
Optics Communications 356 (2015) 389–394
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