We present a theoretical study of the valence-band states in diluted magnet
ic semiconductor quantum wire structures. As a consequence of confinement i
n two directions, the hole states in a quantum wire are known to be mixture
s of heavy- and light-hole components. Due to a strong p-d exchange interac
tion in diluted magnetic semiconductors, the relative contribution of these
components is strongly affected by an external magnetic field B, a feature
that is absent in nonmagnetic quantum wires. This leads, in turn, to a str
ong magnetic-field dependence of the probabilities of various optical dipol
e transitions in diluted magnetic semiconductor quantum wires. Numerical ca
lculations performed for the case of Cd1-xMnxTe/Cd1-x-yMnxMg gamma Te T-sha
ped quantum wires demonstrate the possibility to efficiently control the po
larization characteristics of light emitted from such structures by means o
f an external magnetic field B.