  We study theoretically the recently proposed hole spin initialization scheme
for $p$-doped quantum well or dot systems via coupling to trion states with
sub-picosecond circularly polarized laser pulses. We analyze the efficiency of
spin initialization an predict the intrinsic spin coherence loss due to the
pulse excitation itself as well as the phonon-induced spin dephasing, both
taking place on the timescale of the driving laser pulse. We show that the
ratio of the degree of dephasing to the achieved orientation effect does not
depend on the pulse area but is sensitive to the temperature and detuning. The
optimal excitation parameters are identified.
