Saddle-Shape Whispering Gallery Mode Microresonators

Optical Whispering Gallery Mode (WGM) resonators are an ideal platform for highly sensitive sensors and nonlinear interactions. They exhibit extremely high quality (Q) factors, providing a sensing platform with low detection limit to environmental changes and optical confinement for low threshold nonlinear stimulation. Here we demonstrate a new type of WGM resonator we coin as a Saddle-Shape Microresonator (SSM). The unique modal properties of the SSM's WGMs significantly differs them from spheres, disks, toroids, and other well-known microresonator types. We show that the SSM offers, in addition to the many attractive attributes that are found in "fiber-tip" sphere microresonators, the added characteristic of structural stability of a taper coupled resonator. The combination of these traits make it ideal for strain-based sensing, cavity quantum electrodynamics, and for real life applications in which mechanical tunability of the microresonator's WGMs is essential. The distinctive structure of SSMs – allowing exceptional high mechanical stability as well as mechanical tunability – opens a route to manufacture miniature packaged fiber-coupled WGM microresonators-based devices.