  Coupled-mode induced transparency is realized in a single microbubble
whispering gallery mode resonator. Using aerostatic tuning, we find that the
pressure induced shifting rates are different for different radial order modes.
A finite element simulation considering both the strain and stress effects
shows a GHz/bar difference and this is confirmed by experiments. A transparency
spectrum is obtained when a first order mode shifts across a higher order mode
through precise pressure tuning. The resulting lineshapes are fitted with the
theory. This work lays a foundation for future applications in microbubble
sensing.
