## spectral fluence rate, $$E_{\lambda,\text{o}}$$

https://doi.org/10.1351/goldbook.ST07479
Derivative of @FT07376@, $$E_{\text{o}}$$, with respect to @W06659@, $$\lambda$$. SI unit is $$\text{W m}^{-3}$$; common unit is $$\text{W m}^{-2}\ \text{nm}^{-1}$$.
Note:
All spectral terms may also be defined as derivatives with respect to frequency, $$\nu$$, or wavenumber, $$\tilde{\nu}$$, and are referred to, when necessary, as in terms of @W06659@, or frequency or wavenumber, respectively.
Source:
PAC, 2007, 79, 293. (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 423 [Terms] [Paper]