An apparatus and method forms an optical microresonator and includes spaced high precision ferrules through which an optical fiber passes. A ferrule can be rotatable and movable longitudinally in an axial direction. A clamp engages a ferrule and is operable to secure the optical fiber within a fiber guide of a ferrule such that the optical fiber can be rotated and translated longitudinally in a precision manner for writing a pattern on the optical fiber and forming a resonant waveguide.