4. Nanocomposites as Tunable Optical Materials

In the previous chapter, I have shown that nanocomposites can be used as bulk optical materials. However, this is only possible in the homogeneous regime, which, for applications in the visible spectral range, is reached for particle sizes below 4 nm. The main degrees of freedom that remain available for the design of optical nanocomposites are hence only the constituent materials (host and nanoparticles) and their respective volume fractions. Therefore, the key question is whether significant benefits over conventional materials can be achieved with these degrees of freedom. To answer this question, I, in this chapter, investigate what range of optical properties can be achieved with nanocomposites in the homogeneous regime. Since I have already shown that the Maxwell-Garnett-Mie effective medium theory (EMT) is an accurate tool for the design of nanocomposites in the homogeneous regime, I first use this EMT to investigate the general potential of optical nanocomposites for a wide range of different materials. Subsequently, I present experimental data for specific materials and optical components to confirm these general findings.