Polarization Independent Dual Wavelength Converter Based on FWM in a Single Semiconductor Optical Amplifier

Abstract

Abstract:We present a FWM-based dual channel wavelength converter in an SOA with very small variations in conversion efficiency and a minor polarization related power penalty of 0.9dB between best and worst case of polarization states. ©2009 Optical Society of America IntroductionAll optical wavelength converters (AOWCs) are likely to become key building blocks in future dynamic highcapacity optical networks [1]. Due to their integration potential and power efficiency, semiconductor optical amplifiers (SOAs) have attracted considerable interest as wavelength converters. Error-free wavelength conversion based on cross-gain and cross-phase modulation (XGM, XPM) in a single SOA has been demonstrated at up to 320 Gbps [2]. However, the use of XGM and XPM schemes imply that the same SOA cannot be used to convert signals of different modulation formats or speeds, as required additional manipulation of the signal are needed. Obviously such a solution will not support conversion of more than one channel simultaneously. Recently we demonstrate how by employing a single strong probe and a single SOA, penalty free conversion based on four-wave mixing (FWM) can be achieved for simultaneous two data channels employing different modulation techniques (PSK and ASK) with no noticeable performance variation between them [3], as well as for higher data rates up to 40+10Gb/s (ASK) with some penalty [4]. These demonstrations, however, relied on the accurate alignment of polarization of probe and pumps since the FWM process requires pump and probe signals to have the same polarization inside the active optical cavity.Some schemes proposed in the last decade, aimed to overcome the intrinsic polarization dependence of FWM parametric conversion method [5][6][7][8]. In most of these demonstrations only CW channels [5][6][7] were used. The use of dual orthogonal probes together with an input channel (pump) located at a longer wavelengths to produce a nondegenerated FWM as the converted product, was suggest in [5] but with very low efficiency of -30dB. A modified approach, using the input carrier as well as an output channel located between the two CW probes was also presented [6]. Another CW demonstration used a bi-directional propagation approach in a single-SOA inside a loop enclosing a polarization beam splitter (PBS), but again very low FWM efficiency was obtained [7]. The first experiments showing polarization insensitive FWM, including data over the channels, were shown by Lacey et al.[8], using two SOAs, each one performing FWM in a single optical polarization process, enabling 4 x 2.5Gbps conversion. Some OTDM demultiplexing schemes based on FWM in SOA also employed related techniques to minimize the polarization dependence, such as depolarization between pump and probes [9], co-polarized dualpump (CW+clock) [10] and the already mentioned bi-directional approach, with the signal carrier laying in between the orthogonal CW probes [11].In this paper we report on an optical polarization insensitive AOWC using two orthogonal CW prob...

Polarization insensitive wavelength conversion in a dispersion-engineered silicon waveguide

“…All-optical wavelength conversion (AOWC) is an important feature in future wavelength division multiplexing (WDM) networks. This functionality has been demonstrated in different devices including semiconductor optical amplifiers (SOAs) [1], periodically-poled lithium niobate (PPLN) waveguides [2], and highly nonlinear fibers (HNLFs) [3][4][5][6], based on different nonlinear effects. Recently, nonlinear effects in silicon waveguides have attracted considerable research interests due to compactness, large conversion bandwidth and complementary metal-oxide-semiconductor (CMOS) compatibility.…”

Broadband Polarization-Insensitive Wavelength Conversion Based on Non-Degenerate Four-Wave Mixing in a Silicon Nanowire

“…This functionality has been demonstrated in different devices including semiconductor optical amplifiers (SOAs) [1], periodically poled lithium niobate (PPLN) waveguides [2], and highly nonlinear fibers (HNLFs) [3], based on different nonlinear effects. Recently, nonlinear effects in silicon nanowires have attracted considerable research interests due to compactness, large conversion bandwidth and complementary metal-oxide-semiconductor (CMOS) compatibility.…”

Polarization Insensitive Wavelength Conversion Based on Four-Wave Mixing in a Silicon Nanowire

“…This functionality has been demonstrated in different devices including semiconductor optical amplifiers (SOAs) [1], periodically-poled lithium niobate (PPLN) waveguides [2], and highly nonlinear fibers (HNLFs) [3]- [6], based on different nonlinear effects such as cross-phase modulation (XPM), cascaded second harmonic and difference frequency generation (cSHG/DFG), and four-wave-mixing (FWM). Recently, nonlinear effects in silicon nanowires have attracted considerable research interests due to compactness, large conversion bandwidth and complementary metal-oxide-semiconductor (CMOS) compatibility.…”