Spectroscopic analysis of erbium doped LiNbO3: Effect of dopant concentration, vapor transport equilibration and poling

• Studied effect of Er doping concentration on the spectroscopic properties of Er:LiNbO3.
• Line-strengths & Judd–Ofelt parameters were found to increase till 2.0 mol. % of Er2O3.
• Lithium enrichment resulted in an increase in the line strengths and JO parameters.
• Electrical poling leads to an increase in the value of spectroscopic parameters.

Spectroscopic analysis of as-grown and vapor transport equilibrated erbium doped lithium niobate (Er:LiNbO3; Er:LN) single crystals has been performed on the basis of Judd–Ofelt (JO) theory. Effect of erbium dopant concentration (0.5, 1.0, 2.0, 4.0 and 8.0 mol.% Er) on the absorption characteristics has been investigated. The results reveal that both the line strengths and JO parameters of Er:LN increase till 2.0 mol. % of Er doping concentration and thereafter decrease for 4.0 and 8.0 mol. % Er. This is attributed to increase in the occupancy of Er3+ ions in the clustering site that leads to concentration quenching. In contrast, for vapor transport equilibrated samples the line strengths and JO parameters increased for 0.5 and 1.0 mol. % Er:LN and same was observed to decrease for 2.0 and 4.0 mol. % Er doped samples. In comparison to earlier reports [14,15], improvement in the absorption, line strengths and JO spectroscopic parameters are observed for 0.5 and 1.0 mol. % Er:LN samples on VTE treatment, whereas detrimental effect on VTE is seen on 2.0 and 4.0 mol. % samples. It is observed that poling also enhances the absorption characteristics and JO parameters of the Er:LN sample.

Figure optionsDownload as PowerPoint slide