Gold nanoparticles show surprisingly strong interactions with light in the visible range, which can be divided into scattering, absorption, and photoluminescence. When a nanoparticle absorbs light,... Show moreGold nanoparticles show surprisingly strong interactions with light in the visible range, which can be divided into scattering, absorption, and photoluminescence. When a nanoparticle absorbs light, the corresponding energy is converted to heat, which can affect the environment of the (hot) nanoparticle. This thesis uses scattering and photoluminescence to study the behaviour of optically heated single gold nanoparticles: it discusses the behaviour of single plasmonic vapour nanobubbles, which occur around highly heated nanoparticles immersed in a liquid, the detection of chirality in nano-objects through their absorption and the photothermal effect, the behaviour of gold nanoparticles under sub-picosecond pulsed excitation, and the temperature dependence of pulse-excited photoluminescence of such particles. Show less