On Directly Modulated Reflective Semiconductor Optical Amplifier with Assistance of Birefringent Fiber Loop

Fokion N Karadimoglou,Antonios Hatziefremidis,Zoe V Rizou,Kyriakos E Zoiros

doi:10.3390/photonics9030147

Abstract

Reflective Semiconductor Optical Amplifiers (RSOAs) are essential devices for the development of new generation networks that rely on the convergence of optical and RF communications. Despite their proven potential for direct modulation, RSOAs’ electro-optic response is limited by their finite bandwidth, which hinders their employment both for signal amplification and modulation at the data rates envisioned by the target applications. In this paper, we elaborate on exploiting a Birefringent Fiber Loop (BFL) to enhance the operation of RSOAs as intensity modulators. We apply a mathematically and computationally reduced model to simulate the RSOA response in the time domain, and correlate it with that of the BFL in the frequency domain. We validate the model’s predictions by an extensive comparison of the simulation against experimental results. The reasonable theoretical findings allow us to establish the employed model as an efficient tool for describing electrically driven RSOA operation and its improvement by means of optical notch filtering. Furthermore, we evaluate and quantify the performance of the scheme and the potential range of RSOA direct modulation capability extension enabled by the BFL, which complies with the experimentally observed trends. The outcomes of this thorough study highlight the BFL supportive role in rendering feasible RSOAs’ direct modulation at data rates beyond those deemed possible by their nominal modulation bandwidth.

Highlights

Reflective Semiconductor Optical Amplifiers (RSOAs) constitute operation- and costeffective transceivers for data amplification and modulation required in full-duplex optical access networks [1], radio over fiber systems [2] and microwave photonics [3]
We have proposed applying the specific technique by means of a Birefringent Fiber Loop (BFL), which is characterized by the ease of construction from off-the-shelf fiber components, a potentially stable operation, and flexibly tunable characteristics, first to conventional
Since the BFL aims at enhancing the RSOA modulation bandwidth, we further explored to what extent this is possible

Summary

Introduction

Reflective Semiconductor Optical Amplifiers (RSOAs) constitute operation- and costeffective transceivers for data amplification and modulation required in full-duplex optical access networks [1], radio over fiber systems [2] and microwave photonics [3] These applications benefit from RSOAs’ attractive features, which include wavelength-agile broadband operation, high gain at low driving currents, high modulation linearity, bidirectional signal propagation inside the same active cavity, ability for remote seeding, and a versatile fiber interface [4]. Through the proper discrimination of the frequency components generated by this nonlinear effect, the impairments associated with them can be suppressed and the RSOA low modulation bandwidth can be compensated for This approach is simple in concept, all-optical in nature, straightforward to apply, efficient in use and amenable to implementation by employing different technologies [10–17]. We have proposed applying the specific technique by means of a Birefringent Fiber Loop (BFL), which is characterized by the ease of construction from off-the-shelf fiber components, a potentially stable operation, and flexibly tunable characteristics, first to conventional

Objectives

Results

Conclusion