  Understanding the links between different phases of outflows from active
galactic nuclei is a key goal in extragalactic astrophysics. Here we compare
[OIII] $\lambda\lambda$4960,5008 outflow signatures in quasars with and without
Broad Absorption Lines (BALs), aiming to test how the broad absorption troughs
seen in the rest-frame ultraviolet are linked to the narrow line region
outflows seen in the rest-frame optical. We present new near-infrared spectra
from Magellan/FIRE which cover [OIII] in 12 quasars with 2.1 < z < 2.3,
selected to have strong outflow signatures in CIV $\lambda$1550. Combining with
data from the literature, we build a sample of 73 BAL, 115 miniBAL and 125
non-BAL QSOs with 1.5 < z < 2.6. The strength and velocity width of [OIII]
correlate strongly with the CIV emission properties, but no significant
difference is seen in the [OIII] emission-line properties between the BALs,
non-BALs and miniBALs once the dependence on CIV emission is taken into
account. A weak correlation is observed between the velocities of CIV BALs and
[OIII] emission, which is accounted for by the fact that both outflow
signatures correlate with the underlying CIV emission properties. Our results
add to the growing evidence that BALs and non-BALs are drawn from the same
parent population and are consistent with a scenario wherein BAL troughs are
intermittent tracers of persistent quasar outflows, with a part of such outflow
becoming optically thick along our line-of-sight for sporadic periods of time
within which BALs are observed.
