Linearity and Chirp Investigations on Semiconductor Optical Amplifier as an External Optical Modulator
Eszter Udvary
Budapest University of Technology and Economics, Department of Broadband Infocommunication Systems
udvary@mht.bme.hu
Budapest University of Technology and Economics, Department of Broadband Infocommunication Systems
udvary@mht.bme.hu
This paper provides an overview of the basics and application possibilities of the multifunctional Semiconductor Optical Amplifier (SOA) in Sub-Carrier Multiplexed (SCM) systems. The paper focuses on the linearity investigation of the device. It describes the frequency dependence of the modulation and the harmonic products, the effects of the bias current and the optical power, the mismatch between the light and the electrical signal, the temperature and optical reflection sensitivity. It is shown by numerical simulation and measurements that by using SOA as an external modulator, the device provides acceptable nonlinear distortion for SCM telecommunication systems. Finally, the frequency chirping in external SOA modulator is treated for different operation conditions.