Narrowband fibre laser using a cylindrical optical microresonator as feedback element

Optical microresonators (MR) exhibit a unique combination of high quality factor [1], small mode volume, and good mechanical stability that make these systems of interest for a number of photonics applications, such as narrowband lasers [2] and sensors. Silica microspheres, microdisks and toroids have been used for different applications. Recently, a series of studies using cylindrical MRs as microcylinders and microcapillaries have been reported [3], showing tuning capacities either as a function of the diameter, using tapered fibres, or as a function of the refractive index filling the capillaries. Such tuning capabilities are unable in the case of using other type of MR as for example microspheres.