The ability to investigate the dynamics of single particle at the nano-scale and femtosecond level remained an unfathomed dream for years. It was not until the dawn of the 21st century that nanotechnology and femtoscience gradually merged together and the first ultrafast microscopy of individual quantum dots (QDs) and molecules was accomplished. Ultrafast microscopy studies entirely rely on detecting nanoparticles or single molecules with luminescence techniques, which require efficient emitters to work. However, such techniques cause degradation to the sample as well as yield little information about the dynamics of the system in the excited state. Only in recent years have the efforts to find an alternative compatible technique to study fast processes in nano-objects come into the spotlight.