GRK Seminar:
Cavity optomechanics in the few photon regime using nanowires and photonic crystals

Institut Néel; Université Grenoble-Alpes

Huge developments have been done in the field of cavity optomechanics, essentially by using large photon number to enhance the weak optomechanical interaction. Thus, in our work, we aim at approaching the single photon regime, where a single photon in the cavity mode can have an appreciable impact on the nanowire, which requires g_0>Ωm. This requires operating with ultrasensitive force sensors with small mode volume microcavities, which enhance the electromagnetic field per photon. To do so, we employ photonic crystal (PhC) cavities fabricated at C2N and suspended SiC nanowires, whose vibrating extremity is inserted into the evanescent cavity field. The nanowire being smaller than the wavelength, this allows us to image this confined light field, and to map the optomechanical coupling strength. Then, equiped with a probe laser and an external driving electrode, we measure and map the optomechanical force experienced by the nanowire. Our results are compared to numerical simulations, which also allows to understand the proximity forces arising when approaching the nanostructures.