  The theory of spin orientation of two-dimensional (2D) electron gas has been
developed for intrasubband indirect optical transitions. The monopolar optical
orientation of electrons in the conduction band is caused by the indirect
scattering with virtual intermediate states in the valence band and allowance
for selection rules for interband transitions. The considered mechanism of
optical orientation is shown to be in an inherent relation with the special
Elliot-Yafet mechanism of electron spin relaxation induced by virtual interband
scattering.
