Thermal Self-stabilisation of a Microcavity on the Surface of an Optical Fibre with Active Core

Locking of a spectrum of a microresonator to the wavelength of a pumping laser is crucial to many applications, for instance in optical frequency comb generation [1] . A common approach is to utilise thermal locking that occurs due to energy dissipation within the micro-resonator when the pump laser wavelength lies on the blue wing of its resonance [2] . This, however, makes the feedback strength for compensation of perturbations in the mode spectrum dependent on the pump power, which may be inconvenient, for example, in low-power applications.