This book addresses metrology problems in the fields of dosimetry and bioelectromagnetism as well as presenting a novel type of ultra wideband and non-perturbative sensor based on electro-optics. The exponential growth of wireless signals and their potential benefits or adverse effects on living organisms has become a major social issue nowadays as it directly concerns human health. This question will only be answered when clear causal relationships between expositions of living cells and induced effects are demonstrated. For that purpose, not only do in situ thermal effects have to be measured, but also the actual in situ electromagnetic field. This book addresses these problems and introduces novel measurement methods based on electro-optics.