  We report on an investigation of the redistribution of interlayer coherence
in the trilayer cuprate Bi2Sr2Ca2Cu3O10. The experiment is performed under the
same apical-oxygen phonon excitation discussed in the past for the bilayer
cuprate YBa2Cu3O6.5. In Bi2Sr2Ca2Cu3O10, we observe a similar spectral weight
loss at the transverse plasma mode resonance seen in YBa2Cu3O6.5. However, this
feature is not accompanied by light-enhanced interlayer coherence that was seen
in YBa2Cu3O6+x, for which the transverse plasma mode is observed at equilibrium
even in the normal state. These new observations offer new experimental
perspective in the context of the physics of light-enhanced interlayer coupling
in various cuprates.
