Table 2. Oscillator strength and wave number of Er³⁺ for selected transitions in all prepared samples.

		Oscillator strength fexp (×10−6)
Transition	Wave number (cm−1)	N2Er	Y2Er	Silicate31	Tellurite32	Fluoride30
4I15/2→4I13/2	6532	1.947	1.562	1.681	2.64	1.67
4I15/2→4I11/2	10225	0.793	0.66	0.509	0.89	0.55
4I15/2→4I9/2	12516	1.004	0.413	0.265	0.35	0.32
4I15/2→4F9/2	15361	2.534	2.234	1.804	3.21	2.14
4I15/2→4S3/2	18450	0.308	0.296	0.310	0.65	0.51
4I15/2→2H11/2	19231	10.175	8.656	5.696	13.73	3.44
4I15/2→4F7/2	20492	1.897	1.748	1.548	2.32	0.87