The SNO+ experiment is the follow up of the SNO experiment, replacing the heavy water volume with about 780 tonnes of liquid scintillator (LAB) in order to lower the sensitive energy threshold. The 6000 m.w.e. natural rock shielding, and the use of ultra-clean materials makes the detector suitable for the detection of pep and CNO solar neutrinos, geo-neutrinos, reactor neutrinos and the possible observation of neutrinos from supernovae. In addition to this program, SNO+ will also search for <sup>150</sup>Nd neutrinoless double beta decay, loading the scintillator with natural Neodymium. After a review of the general SNO+ detector and some of the potential physics, a discussion of the optical calibration system will be presented.