Focused ion beam engraved phase-shifted Bragg grating microcavity resonator

Abstract

A cavity with minimal-volume confinement was created in a microfiber engraving a high-contrast phase-shifted Bragg grating by focused ion beam. While waveguiding by the air/silica boundary provides a diffraction-limited 2D confinement, the grating introduces the third degree of confinement. Theoretical simulations verified the phase-shifted cavity confinement and showed a reasonable agreement with the experimental demonstration. This cavity can find a variety of applications ranging from sensing to quantum dynamic experiments