Table 2.

Effect of gain fiber length on pumping efficiency, fundamental mode content, and m² factor.

Gain Fiber Length	Pumping Efficiency	Fundamental Ratio	m2 Factor
3 m	53.5%	66%	1.6
4 m	58.3%	71.8%	1.44
5 m	64.8%	73%	1.3
6 m	70.6%	75%	1.33
7 m	72.4%	76%	1.33
8 m	72.4%	79%	1.22
9 m	73.1%	74%	1.34
10 m	71%	71%	1.42
11 m	70.6%	71%	1.43
12 m	70.2%	72%	1.4