Photonic chip based tunable slow and fast light via stimulated Brillouin scattering
ABSTRACT We report the first (to our knowledge) demonstration of photonic chip based tunable slow and fast light via stimulated Brillouin scattering. Slow, fast, and negative group velocities were observed in a 7 cm long chalcogenide (As(2)S(3)) rib waveguide with a group index change ranging from ~-44 to +130, which results in a maximum delay of ~23 ns at a relatively low gain of ~23 dB. Demonstration of large tunable delays in a chip scale device opens up applications such as frequency sensing and true-time delay for a phased array antenna, where integration and delays ~10 ns are highly desirable.
SourceAvailable from: Chang-Ling Zou[Show abstract] [Hide abstract]
ABSTRACT: Stimulated Brillouin scattering (SBS) is a very fundamental interaction between light and travelling acoustic waves, which is mainly attributed to the electrostriction and photoelastic effects with the interaction strength being orders of magnitude larger than other nonlinearities. Although various photonic applications for all-optical light controlling based on SBS have been achieved in optical fiber and waveguides, the coherent light-acoustic interaction remains a challenge. Here, we experimentally demonstrated the Brillouin scattering induced transparency (BSIT) in a high quality optical microresonantor. Benefited from the triple-resonance in the whispering gallery cavity, the photon-phonon interaction is enhanced, and enables the light storage to the phonon, which has lifetime up to 10us. In addition, due to the phase matching condition, the stored circulating acoustic phonon can only interact with certain direction light, which leads to non-reciprocal light storage and retrieval. Our work paves the way towards the low power consumption integrated all-optical switching, isolator and circulator, as well as quantum memory.Nature Communications 08/2014; 6. DOI:10.1038/ncomms7193 · 10.74 Impact Factor
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ABSTRACT: Harnessing nonlinear optical effects in a photonic chip scale has been proven useful for a number of key applications in optical communications. Microwave photonics (MWP) can also benefit from the adoption of such a technology, creating a new concept of nonlinear integrated MWP. Here, we look at the potential of using nonlinear optical effects in a chip scale to enable RF signal processing with enhanced performance. We review a number of recent results in this field, with particular focus on the creation of frequency agile and high suppression microwave bandstop filters using on-chip stimulated Brillouin scattering. We also discuss the future prospect of nonlinear integrated MWP to enable a general purpose, programmable analog signal processor, as well as compact, high performance active microwave filters with enhanced energy efficiency.Journal of Lightwave Technology 10/2014; 32(20):3421-3427. DOI:10.1109/JLT.2014.2306676 · 2.86 Impact Factor
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ABSTRACT: Electromagnetically induced transparency (EIT) [1, 2] provides a powerful mechanism for controlling light propagation in a dielectric medium, and for producing both slow and fast light. EIT traditionally arises from destructive interference induced by a nonradiative coherence in an atomic system. Stimulated Brillouin scattering (SBS) of light from propagating hypersonic acoustic waves  has also been used successfully for the generation of slow and fast light [4-7]. However, EIT-type processes based on SBS were considered infeasible because of the short coherence lifetime of hypersonic phonons. Here, we demonstrate a new Brillouin scattering induced transparency (BSIT) phenomenon generated by acousto-optic interaction of light with long-lived propagating phonons [8, 9]. This transparency is intrinsically non-reciprocal due to the stringent phase-matching requirements. We demonstrate BSIT in a silica microresonator having a specific, naturally occurring, forward-SBS phase-matched modal configuration [8, 9]. BSIT is shown to enable extremely compact and ultralow power slow/fast light generation with delay-bandwidth product comparable to state-of-the-art SBS systems.