![](/images/menggu/170.jpg)
Absorption Imaging of an Ultracold Gas
Page | 7 Optical Depth 200 400 600 800 1000 200 400 600 800 1000 1200-0.5 0 0.5 1 1.5 2 2.5 3 3.5 4 Equation (5.1)3 Equation (5.2) where I 0 is the intensity of the radiation at the source, and I is the observed intensity after a given path.