We present a study of the microbubble formation using thinned optical fiber tips. Our study is carried out in an absorbent medium provided by a multiwall carbon nanotubes (MWCNT) solution. We focus on the radius of microbubble formation and its dependence on pumping power (pp) from an external light source, time of the pp, diameters of the tips, and concentration of MWCNT. We observe that using tapered single-mode optical fiber tips minor pp is needed for the microbubble formation, compared to a conventional optical fiber (not tapered). We observe that the experimental behavior of growth of generated microbubbles is still in agreement with the previously established Plesset–Zwick theory.