Field Strength Correlators and Gluon Condensates at Finite Temperature from Renormalization Group Smoothing

We summarize recent attempts to extract characteristics of non-perturbative vacuum structure from lattice measurements of the gauge invariant field strength correlator. As an alternative to cooling, we propose to apply the renormalization group (RG) smoothing method in lattice studies. For pure SU(2) gauge theory we present magnetic and electric correlation lengths and condensates related to various correlators over a temperature range of 0.7 T_{dec} < T < 1.9 T_{dec}