macro.resonant_optical_depth

macro.resonant_optical_depth(number_density, length, wavelength, factor=1.0)

Resonant intensity optical depth N sigma_0 L of a cold, weak-field medium.

Parameters

Name	Type	Description	Default
number_density	float	Atoms per cm^3.	required
length	float	Medium length, in cm.	required
wavelength	float	Transition wavelength, in nm.	required
factor	float	Dipole moment squared relative to the cycling transition.	1.0

Returns

Name	Type	Description
	float	The optical depth OD; intensity transmission is exp(-OD). Doppler
	float	broadening reduces the peak.