In this work we present the state of the art of our work to obtain an infrared optical amplifier in which Er(3+) doped SiO(2) sensitised with Si nanoclusters (Si-nc) act as the active material to provide the signal amplification. As a result of a careful optimisation of the deposition parameters we have achieved that the Er(3+) fraction coupled with the Si-nc with respect to the total optically active Er(3+) content is about 23%. This result has been determined both by quantitative measurements of the first excited state population and by pump and probe amplification measurements under non-resonant pumping, where 1 dB cm(-1) of internal gain (reduction of 2 dB cm(-1) of the initial absorption losses) has been obtained. We will discuss several material issues that are mandatory to address and then overcome in order to optimise the fraction of Er(3+) coupled to Si-nc, with the aim of exciting all the ions through indirect transfer. In particular we will address: carrier absorption (CA) in Si-nc, cooperative up-conversion and non-radiative recombination in Er(3+), together with the distance dependent interaction and Auger back-transfer processes in the Er/Si-nc coupled system.