  Optical half-wave microresonators enable to control the optical mode density
around a quantum system and thus to modify the temporal emission properties. If
the coupling rate exceeds the damping rate, strong coupling between a
microresonator and a quantum system can be achieved, leading to a coherent
energy exchange and the creation of new hybrid modes. Here, we investigate
strong coupling between two adjacent lambda/2 Fabry-P\'erot microresonators,
where the resonance of one microresonator can be actively tuned across the
resonance of the other microresonator. The transmission spectra of the coupled
microresonators show a clear anticrossing behavior, which proves that the two
cavity modes are strongly coupled. Additionally, we can vary the coupling rate
by changing the resonator geometry and thereby investigate the basic principles
of strong coupling with a well-defined model system. Finally, we will show that
such a coupled system can theoretically be modelled by coupled damped harmonic
oscillators.
