Abstract

Stimulated Brillouin scattering (SBS) is a strong nonlinear interaction between the incident pump photons and the acoustic phonons in a guiding structure [1]. This results in the scattering of light from the pump field to the Stokes field which is frequency-shifted by ~10 GHz. SBS has been extremely useful in a number of applications: ultra-narrow bandwidth laser, sensing, slow and fast-light, microwave signal processing, and ns scale light signal storage [2]. A number of geometries that can be used to harness SBS such as fibers, embedded waveguides, suspended waveguides and resonators in various materials such as silica, chalcogenide, silicon, calcium fluoride [2]. Off all the platforms, As₂S₃ waveguide devices have been demonstrated to be the most suitable for integrated efficient SBS [3]. While silicon offers CMOS compatibility, it suffers from multiphoton absorption and free-carrier absorption, which affects the SBS performance [4]. Furthermore, extra processing is required for fabricating suspended nanowires, which makes it hard to make longer lengths [5]. Chalcogenide glasses have demonstrated both large Kerr and SBS nonlinearity and very low two photon absorption at 1.5µm pump. Previously, the SBS gain of 23dB in As₂S₃ was reported [3]. In addition, chalcogenide waveguides can be fabricated on a CMOS compatible platform could result in a hybrid chalcogenide-silicon platform for enabling opto-electronic integration of applications based on SBS and Kerr nonlinearity [6].

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