  The magnetic field induced circular polarization of near infrared
photoluminescence in Bi-doped pure silica glass was studied in the spectral
range of 660 - 1600 nm covering three excited state levels. The highest degree
of magnetic circular polarization of luminescence was observed in the lasing,
first excited state (peak emission at 1440 nm). The results of variable
temperature and variable magnetic field measurements allows to conclude that
the near infrared luminescence originates from an isolated non-Kramers doublet
of the even-electron system.
