It is a matter of pleasure to present the Luminescence studies on Sm3+, Eu3+, Dy3+, Er3+ and Er3+/Yb3+ ions in potassium niobate silicate glasses. The prime objectives of this book are: To prepare Potassium Niobate Silicate (K- Nb- Si) glasses doped Sm3+, Eu3+, Dy3+, Er3+ and Er3+/Yb3+ ions To characterize and optimize the prepared glasses by the conventional spectroscopic techniques like absorption, emission, decay, etc. measurements. To identify the optimum concentrations of dopant ions for efficient luminescence. To find lifetime of the emission level of rare earth ion by increasing active...