where the parameters 𝝁 and 𝜅 represent, respectively, the direction of the externally applied field and the so-called focus factor. The parameter 𝜅 can take on any value from 0 (randomly oriented ensemble of emitters) to infinity (perfectly aligned ensemble of emitters) and is directly correlated with the average deviation angle (𝜃 ̅ ) of the emitters relative to the unit vector 𝝁 (see Figure in Supporting Information).