  We study the X-ray transient Swift J1745-26, using observations obtained from
its outburst in September 2012, up to its decay towards quiescence in March
2013. We obtained optical and infrared observations, through override programme
at ESO/VLT with FORS2 and ISAAC instruments, and archival optical (VLT/VIRCAM),
radio and X-ray (Swift) observations, to build the lightcurve and the
broad-band Spectral Energy Distribution (SED) of Swift J1745-26. We show that,
during its outburst and also during its decay towards quiescence, Swift
J1745-26 SED can be adjusted, from infrared up to X-rays, by the sum of both a
viscous irradiated multi-colour blackbody emitted by an accretion disk, and a
synchrotron powerlaw at high energy. In the radio domain, the SED arises from
synchrotron emission from the jet. While our SED fitting confirms that the
source remained in the low/hard state during its outburst, we determine an
X-ray spectral break at frequency 3.1 < nu_break < 3.4 x 10^14 Hz, and a radio
spectral break at 10^12 Hz < nu_break < 10^13 Hz. We also show that the system
is compatible with an absorption Av of ~7.69 magnitudes, lies within a distance
interval of D~[2.6-4.8] kpc, with an upper limit of orbital period P_orb = 11.3
hours, and that the companion star is a late-type star of spectral type in the
range K0 - M0 V, confirming that the system is a low-mass X-ray binary. We
finally plot the position of Swift J1745-26 on an optical-infrared - X-ray
luminosity diagram: its localization on this diagram is consistent with the
source staying in the low-hard state during outburst and decay phases.
