Parameter | Definition |
φP | The pump photon flux |
φs | The signal photon flux |
The stimulated emission cross section for Er+3 | |
The absorption cross section for Er+3 | |
The stimulated emission cross section for Yb+3 | |
The absorption cross section for Yb+3 | |
A21 | The spontaneous emission rate of Er+3 |
A65 | The spontaneous emission rate Yb+3 |
K and K' | The coefficient of energy transfer (m3∙s−1) for the concentrations of Er+3 and Yb+3 |
Cup | The up conversion coefficient |