Physics

Dr. Siddharth Tallur
IIT-Bombay

Abstract:  Chipscale cavity opto-mechanics studies the interaction of photons and phonons in micro-resonators that simultaneously host high quality factor mechanical and optical resonances with strong spatial overlap. The past decade of research in this field has proven that energy and information transfer between the optical and acoustic domains can be mediated via strong opto-mechanical coupling in such structures, which can enable several versatile applications. In this talk, I will discuss a case study of an integrated silicon opto-mechanical system, and highlight the various experimental capabilities that can be exploited in such a highly scaled platform. One of the novel applications enabled by such a system is direct conversion of intensity modulation of laser light in the near-infrared regime to motional electric current wherein the device acts as a photon-phonon translator. The ultra-high displacement sensitivity of the opto-mechanical resonator, typically in the order of magnitude of attometer-per-root-Hertz, also enables high resolution sensing of physical quantities such as mass, force and acceleration. I will also demonstrate the unique ability of such a system to use the back-action of the optical field to launch self-sustained oscillations of the mechanical mode with zero flicker noise, which can be used as a stable timing reference as a resonant sensor, and as a low noise parametric amplifier, as well as multi-GHz mechanical oscillations. The takeaway message for attendees would be an appreciation for the various application potentials for the techniques that form the core of opto-mechanical experiments. Towards the end of the talk, I will briefly highlight the on-going research activities in our group in the area of electro-opto-mechanics and other MEMS and integrated sensing applications.