Experimental Validation of Numerical Simulations and Performance Analysis of a Coherent Optical-OFDM Transmission System Employing a Semiconductor Optical Amplifier

Abstract

In this paper, a numerical model of Semiconductor Optical Amplifiers (SOA) is experimentally validated in terms of the Alpha Factor and the Four-Wave Mixing (FWM). Besides, a Coherent Optical-Orthogonal Frequency Division Multiplexing (CO-OFDM) simulation platform is used to confirm the good agreement between the measured and the simulated Error Vector Magnitude (EVM) of a received signal amplified by the studied SOA in an optical transmission link. In addition, the performance of the SOA on the amplification of a 10.94 Gb/s QPSK CO-OFDM signal is numerically analyzed with respect to the Amplified Spontaneous Emission (ASE) noise, the Alpha Factor, the output saturation power of the SOA and the bit rate. Index Terms-Advanced modulation formats, coherent optical-OFDM, four wave mixing (FWM), phase-amplitude coupling, semiconductor optical amplifier (SOA).

Robustness analysis of a parallel two-box digital polynomial predistorter for an SOA-based CO-OFDM system

“…The CO-OFDM transmitter and receiver are modeled in Matlab while the SOA is modeled in ADS Ptolemy using the carrier density rate and optical signal field propagation equations [8]. Optical Amplifier parameters are tuned to realistically fit a 750µm long commercial SOA (INPHENIX-IPSAD1501).…”

“…It is also proposed to apply clipping along with digital predistortion to mitigate performance degradation. Some of the present authors have investigated similar problems by considering nonlinear effects originating from optical components, with a special focus on Semiconductor Optical Amplif ers (SOAs) [8] [9]. Interesting features such as low cost, large optical bandwidth and small form factor [10] make SOAs an interesting alternative to the high-end EDFAs for some application scenarios [11].…”

A Joint Linearization/Companding Approach for Improving a CO-OFDM Transmitter

“…We first proceeded to the simulation of the CO-OFDM system with the objective of designing and comparing various candidate algorithms for PAPR reduction and linearization. Our implementation relies on a self-developed SOA model [2], which has been fitted to simulate a commercially available bulk 750 µm long SOA (INPHENIX-IPSAD1501), so that it yields a very good matching between simulated results and experimental results. The overall structure of the system is illustrated in Fig.…”

“…OFDM is considered as a strong candidate for future Wavelength-Division-Multiplexing (WDM) systems due to its many advantages, such as high spectral efficiency, simple compensation of linear channel impairments, dynamic bandwidth allocation capability in a multiuser context, and powerful digital signal processing (DSP)-based implementation [1]. It has been recently demonstrated in [2] that SOA may be a pertinent choice for amplifying Coherent Optical-OFDM (CO-OFDM), for its interesting features such as large optical bandwidth, small size and possibility of integration at limited cost. Another study [3], conducted in an industrial context, demonstrates the practical feasibility of a SOA-based metro-access infrastructure, with the simultaneous operation of multiple services using different coherent modulation formats.…”

“…Note also that SOA might be suitable for some low cost coherent systems [4] [5]. However, the authors in [2] report that SOA-based systems may suffer from nonlinear effects such as four wave mixing (FWM) and phase-amplitude coupling, as a result of large PAPR that is typically associated with OFDM signals. In a recent paper [6], we considered various companding schemes for improving a SOA-based CO-OFDM system performances.…”