  We consider the possibility of measuring the true width of the narrow Fe II
optical lines observed in spectra of the Weigelt blobs in the vicinity of Eta
Carinae. The lines originate as a result of stimulated amplification of
spontaneous emission of radiation in quantum transitions between energy levels
showing inverted population (Johansson & Letokhov, 2002, 2003, 2004). The lines
should have a subDoppler spectral width of 30-100 MHz, depending on the
geometry of the lasing volume. To make measurements with a spectral resolution
of R>10^7 and an angular resolution better than 0.1 arcsec, we suggest the use
of the Brown-Twiss-Townes optical heterodyne intensity correlation
interferometry. The estimates made of the S/N ratio for the optical heterodyne
astrophysical laser experiment imply that it is feasible.
