Compositional dependence of Stark splitting and spectroscopic properties in Yb3+-doped lead silicate glasses

•Effect of field strength of alkali/alkaline on Yb3+ doped silicate glass is obtained.•High modifier field strength provides high ‘crystal-field’ and asymmetry degree of Yb3+.•Absorption and emission cross section and emission linewidth of Yb3+ increase by >64 %.•Spontaneous emission probability of Yb3+ enhanced 28 % by doubling modifier field strength.