Studies of geometrical profiling in fabricated tapered optical fibers using whispering gallery modes spectroscopy

Abstract

This paper experimentally demonstrates a method for geometrical profiling of asymmetries in fabricated thin microfiber tapers with waist diameters ranging from ~10 to ~50 µm with submicron accuracy. The method is based on the analysis of whispering gallery mode resonances excited in cylindrical fiber resonators as a result of evanescent coupling of light propagating through the fiber taper. The submicron accuracy of the proposed method has been verified by SEM studies. The method can be applied as a quality control tool in fabrication of microfiber based devices and sensors or for fine-tuning of microfiber fabrication setups .

Discovery of parabolic microresonators produced via fiber tapering

“…2, following the simple model for predicting taper shape given tapering parameters from [15]. The actual profile of the radius r(z) as a function of longitudinal position along the TUT z, is precisely characterized with a probe microtaper with a 1.7 µm diameter waist (N =15) using the method described in detail in [19][20][21]. Put briefly, the probe taper is oriented transverse to the TUT and placed into contact so as to efficiently couple light propagating through the probe taper to the whispering gallery modes along the perimeter of the TUT.…”