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IEEE Journal of Selected Topics in Quantum Electronics

On the Role of High-Order Coherent Population Oscillations in Slow and Fast Light Propagation Using Semiconductor Optical Amplifiers

Seán Ó Dúill, Ronan F. O'Dowd, G. Eisenstein

Published Jan 1, 2009• 20 citations
Publisher

Abstract

In this paper, we present a numerical investigation of the phase shift experienced by the detected envelope of a sinusoidally modulated optical carrier propagating in a nonlinear semiconductor optical amplifier. The model we employed accounts for high-order coherent population oscillations. As such, it allows for large gain levels and arbitrary modulation indexes of the input field. We highlight the role of the fields that are generated by high-order nonlinearities and compare the results with those of more common small-signal nonlinear models. We find that conventional models suffice only for low powers, small modulation indexes, and moderate amplifier gain levels.

DOI
10.1109/jstqe.2009.2013177

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We developed a predictive model describing harmonic generation and intermodulation distortions in semiconductor optical amplifiers (SOAs). This model takes into account the variations of the saturation parameters along the propagation axis inside the SOA, and uses a rigorous expression of the gain oscillations harmonics. We derived the spurious-free dynamic range (SFDR) of a slow light delay line based on coherent population oscillation (CPO) effects, in a frequency range covering radar applications (from 40 kHz up to 30 GHz), and for a large range of injected currents. The influence of the high order distortions in the input microwave spectrum is discussed, and in particular, an interpretation of the SFDR improvement of a Mach-Zehnder modulator by CPOs effects in a SOA is given.