We study the magnetoexciton polaritons in planar semiconductors microcaviti
es by a quantum approach developed in the strong and weak magnetic-field li
mits. Ht is shown that the vacuum Rabi splittings with different Landau lev
el indices are close to each other and tend to be proportional to B at suff
iciently large values of the magnetic field. Also, we show that the calcula
ted results are in good agreement with the experimental observations. [S016
3-1829(99)10215-7].