Brillouin distributed measurement techniques have been extensively<br> developed for structural health monitoring using fibre optic nerve<br> systems. The recent advancement in the spatial resolution capabilities<br> of correlation-based Brillouin distributed technique have reached the<br> sub-mm regime, making this approach a suitable candidate for monitoring<br> and characterizing integrated photonic devices. The small dimension<br> associated with the short length of these devices-on the order of the<br> cm- and mm-scale-requires high sensitivity detection techniques and<br> sub-mm spatial resolution. In this paper, we provide an overview of the<br> different Brillouin sensing techniques in various micro-scale structures<br> such as photonic crystal fibres, microfibres, and on-chip waveguides. We<br> show how Brillouin sensing is capable of detecting fine transverse<br> geometrical features with the sensitivity of a few nm and also extremely<br> small longitudinal features on the order of a few hundreds of mu m. We<br> focus on the technique of Brillouin optical correlation domain analysis<br> (BOCDA), which enables such high spatial resolution for mapping the<br> opto-acoustic responses of micro-scale waveguides.
On-chip multi-stage optical delay based on cascaded Brillouin light
storage
Birgit Stiller,
Moritz Merklein,
Christian Wolff,
Khu Vu,
Pan Ma,
Christopher G. Poulton,
Stephen J. Madden,
Benjamin J. Eggleton
Storing and delaying optical signals plays a crucial role in data<br> centers, phased array antennas, communication, and future computing<br> architectures. Here, we show a delay scheme based on cascaded Brillouin<br> light storage that achieves multi-stage delay at arbitrary positions<br> within a photonic integrated circuit. Importantly these multiple<br> resonant transfers between the optical and acoustic domain are<br> controlled solely via external optical control pulses, allowing<br> cascading of the delay without the need of aligning multiple structural<br> resonances along the optical circuit. (c) 2018 Optical Society of<br> America.
Brillouin spectroscopy of a hybrid silicon-chalcogenide waveguide with
geometrical variations
Atiyeh Zarifi,
Birgit Stiller,
Moritz Merklein,
Yang Liu,
Blair Morrison,
Alvaro Casas-Bedoya,
Guanghui Ren,
Thach G. Nguyen,
Khu Vu, et al.
Recent advances in design and fabrication of photonic-phononic<br> waveguides have enabled stimulated Brillouin scattering in silicon-based<br> platforms such as underetched silicon waveguides and hybrid waveguides.<br> Due to the sophisticated design and, more importantly, high sensitivity<br> of the Brillouin resonances to geometrical variations in micro- and<br> nano-scale structures, it is necessary to have access to the localized<br> opto-acoustic response along those waveguides to monitor their<br> uniformity and maximize their interaction strength. In this Letter, we<br> design and fabricate photonic-phononic waveguides with a deliberate<br> width variation on a hybrid silicon-dialcogenide photonic chip and<br> confirm the effect of the geometrical variation on the localized<br> Brillouin response using a distributed Brillouin measurement. (C) 2018<br> Optical Society of America
Brillouin-based light storage and delay techniques
Moritz Merklein,
Birgit Stiller,
Benjamin J. Eggleton
Storing or delaying optical signals is of key interest for fundamental research and applications in radar, microwave signal processing, quantum information as well as optical communication systems. Delay systems based on stimulated Brillouin scattering (SBS), a coherent interaction between optical and acoustic waves can be implemented in optical fiber or chip-scale platforms, operate at room temperature and can be fully controlled via the optical pump wave. In this article, we review delay and storage techniques based on SBS. We present SBS slow-light, fiber delay lines based on Brillouin dynamic gratings, Brillouin quasi-light storage and Brillouin-based light storage via photon-phonon conversion and compare their performance. In this process, we also include an overview of different platforms used for Brillouin light storage and delay schemes, such as optical fiber, planar soft-glass waveguides, and silica fiber-tip resonators.
Highly localized distributed Brillouin scattering response in a photonic
integrated circuit
Atiyeh Zarifi,
Birgit Stiller,
Moritz Merklein,
Neuton Li,
Khu Vu,
Duk-Yong Choi,
Pan Ma,
Stephen J. Madden,
Benjamin J. Eggleton
The interaction of optical and acoustic waves via stimulated Brillouin<br> scattering (SBS) has recently reached on-chip platforms, which has<br> opened new fields of applications ranging from integrated microwave<br> photonics and on-chip narrow-linewidth lasers, to phonon-based optical<br> delay and signal processing schemes. Since SBS is an effect that scales<br> exponentially with interaction length, on-chip implementation on a short<br> length scale is challenging, requiring carefully designed waveguides<br> with optimized opto-acoustic overlap. In this work, we use the principle<br> of Brillouin optical correlation domain analysis to locally measure the<br> SBS spectrum with high spatial resolution of 800 mu m and perform a<br> distributed measurement of the Brillouin spectrum along a spiral<br> waveguide in a photonic integrated circuit. This approach gives access<br> to local opto-acoustic properties of the waveguides, including the<br> Brillouin frequency shift and linewidth, essential information for the<br> further development of high quality photonic-phononic waveguides for SBS<br> applications. (C) 2018 Author(s).
Contact
Research Group Birgit Stiller
Max Planck Institute for the Science of Light Staudtstr. 2 91058 Erlangen, Germany
