  We report on the alteration of photon emission properties of a single trapped
ion coupled to a high finesse optical fiber cavity. We show that the vacuum
field of the cavity can simultaneously affect the emissions in both the
infrared (IR) and ultraviolet (UV) branches of the $\Lambda-$type level system
of $^{40}\mathrm{Ca}^+$ despite the cavity coupling only to the IR transition.
The cavity induces strong emission in the IR transition through the Purcell
effect resulting in a simultaneous suppression of the UV fluorescence. The
measured suppression of this fluorescence is as large as 66% compared with the
case without the cavity. Through analysis of the measurement results, we have
obtained an ion-cavity coupling of $\bar{g}_0 = 2\pi\cdot (5.3 \pm 0.1)$ MHz,
the largest ever reported so far for a single ion in the IR domain.
