ABSTRACT
Laser noise has been of high interest for many years, both in the context of fundamental physics and for a variety of laser applications. This chapter is meant to be an introduction into the area of laser noise. It focuses on single-frequency lasers, which have been studied in most detail and deserve significant attention for various reasons, including the fact that their understanding also greatly facilitates the understanding of more complicated situations — for example, in mode-locked lasers. A common situation is that a solid-state laser is pumped with a high-power semiconductor laser diode, with the latter exhibiting significant mode partition noise. Even if the total power of the semiconductor laser is fed into the solid-state laser, the resulting intensity noise of the solid-state laser can be significant, because the degree of pump absorption can significantly vary across the spectrum of the pump diode, so that the absorbed pump power fluctuates more than the total incident pump power.
