Spin noise spectroscopy in semiconductors has matured during the past nine years into a versatile and well developed
technique being capable to unveil the intrinsic and unaltered spin dynamics in a wide range of semiconductor systems.
Originating from atom and quantum optics as a potential true quantum non-demolition measurement technique, SNS is
capable of unearthing the intricate dynamics of free or localized electron and hole spins in semiconductors being
eventually coupled to the nuclear spin bath as well. In this contribution, we review shortly the major steps which inspired
the success of spin noise spectroscopy in semiconductors and present the most recent extensions into the low-invasive
detection regime of the spin dynamics for the two extreme limits of very high and extremely low rates of spin
decoherence, respectively. On the one hand, merging ultrafast laser spectroscopy with spin noise spectroscopy enables
the detection of spin noise with picosecond resolution, i.e., with THz bandwidths yielding access to otherwise concealed
microscopic electronic processes. On the other hand, we present very high sensitivity SNS being capable to measure the
extremely long spin coherence of single holes enclosed in individual quantum dots venturing a step forward towards true
optical quantum non-demolition experiments in semiconductors. In addition, higher-order spin noise statistics of, e.g.,
single charges can give information beyond the linear response regime governed by the fundamental fluctuationdissipation
theorem and thereby possibly shed some light on the nested coupling between electronic and nuclear spins.