  In this paper, we aim to study the main properties and luminosity function
(LF) of the [OII] emitters detected in the OTELO survey in order to
characterise the star formation processes in low-mass galaxies at $z\sim1.43$
and to constrain the faint-end of the LF.
  Here, we describe the selection method and analysis of the emitters obtained
from narrow-band scanning techniques. In addition, we present several relevant
properties of the emitters and discuss the selection biases and uncertainties
in the determination of the LF and the star formation rate density (SFRD).
  We confirmed a total of 60 sources from a preliminary list of 332 candidates
as [OII] emitters. Approximately 93% of the emitters have masses in the range
of $10^{8}<M_{*}/{\rm M_{\odot}}<10^{9}$. All of our emitters are classified as
late-type galaxies, with a lower value of $(u-v)$\, when compared with the rest
of the emitters of the OTELO survey. We find that the cosmic variance strongly
affects the normalisation ($\phi^*$) of the LF and explains the discrepancy of
our results when compared with those obtained from surveys of much larger
volumes. However, we are able to determine the faint-end slope of the LF,
namely, $\alpha=-1.42\pm0.06$, by sampling the LF down to $\sim1$\,dex lower
than in previous works. We present our calculation of the SFRD of our sample
and compare it to the value obtained in previous studies from the literature.
