Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE

Group delay tuning in three-beam interferometers: an alternative to photonic crystals for generating slow and fast light

J. M. Arias, A. Sánchez-Meroño, Marı́a del Mar Sánchez-López, Ignacio Moreno

Published Apr 24, 2012• 0 citations

Abstract

In this work, we explore the generation of slow and fast light (SFL) in a linear and passive three-beam interferometer for center pulse frequency close to the transmission minima. We show that the group delay can be tuned from subluminal to superluminal values by simply changing the length of one of the interferometer's arms. Some figures of merit of this three-beam interferometer as an SFL system are discussed, namely fractional delay and pulse distortion. We build our interferometers using 50-Ω coaxial cables and 1x3 power splitters in order to perform the experiments in the radiofrequency range, where a full frequency-domain characterization of them can be performed with a vector network analyzer. Together with the frequency domain results, we present direct measurement of the group delay in time domain. Fractional delays of ±25% were measured for a train of sinusoidally modulated wavepacket with 300 kHz repetition rate. Additionally, a Lithium Niobate interferometer operative in the optical range (1.55 μm) was simulated and discussed. This system is proposed as an alternative to active systems and photonic band-gap structures for sustaining both slow and fast light, with special emphasis in sensing purposes.

DOI: 10.1117/12.922091

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