from numpy import pi
from scipy.constants import hbar

"""
Explanation: EIT lab notes
A notebook for relevant calculations regarding the observation conditions for EIT slow light
Goal: observe slow light with 10% pulse delay by Nov 1, 2018
End of explanation
"""


# Find the power for a 3 mm diameter gaussian beam with stated intensity:
r = 0.3/2 # units of cm
A = pi*r**2
P = 2.5e-3 * A
P*1e6 # microWatts

"""
Explanation: Notes from Klein et al 2011 (doi:10.1103/PhysRevA.83.013826)
<img src="fig/EIT_setup_Klein_et_al_2011.png" width=400>
Levels used are F=2 -> F'=1 with control field sigma+ and probe sigma-. Stated variables for their primary data figure are: T = 42 C, I = 2.5 mW/cm2, and beam diameter 3 mm. So we'll translate these to power etc. Half-waveplate is set such that the control and probe have 10:1 intensity ratio. Assuming the stated intensity is either the control or the total... which should be within 10% of each other.
https://www.ophiropt.com/laser--measurement/power-density-calculator suggests that 3 mm diameter (1/e^2) at 100 uW power, gives peak intensity of 2.83 mW/cm^2, compared to 2.5 mW/cm^2 stated by Klein et al. Still, that's a good ballpark. Now, re-create this calculation:
End of explanation
"""


