A new approach to the quantum description of resonance multiphoton pro
cesses is suggested. This approach is based on the idea that Hamiltoni
ans for multiphoton transitions can be constructed in terms of composi
te photon states which are called ''photon clusters.'' Along with this
approach, we shall describe quantum optics in terms of photon cluster
s which belong to a finite-dimensional subspace generated by photon st
ates with a definite discrete phase. Hamiltonians for resonance multip
hoton transitions in two-level systems are formulated in terms of phot
on clusters rather than in terms of the usual single-photon states. Th
e supersymmetry of these Hamiltonians is investigated.