  We propose a realization of the quantum transistor for coherent light fields
for the fibre-coupled microdisk cavities. We demonstrate by combining numerical
and analytical methods that both in strong coupling and bad cavity limits it is
possible to change system's behaviour from being fully transparent to being
fully reflective by varying the amplitude of the external control field. We
remark that tuning the amplitude of the control field is significantly easier
in the experimental setting than tuning cavity-atom coupling strength which was
suggested in [Phys. Rev. A 90, 053822 (2014)] for two-level atoms and works
only in the strong coupling limit. We also demonstrate the possibility of
controlling the statistics of the input coherent field with the control field
which opens the venue for obtaining quantum states of light.
