Measured $\Delta t$ between lines 1,2 and 2,3.

1,2 = 0.88ms

2,3 = 1.48ms

Calculated energy differences between lines 1,2 and 2,3.

1,2 = 147 MHz

2,3 = 247 MHz

Measured $\Delta t$ between lines 1,2 and 2,3.

1,2 = 0.34ms

2,3 = 0.64ms

Calculated energy differences between lines 1,2 and 2,3.

1,2 = 56.8 MHz

2,3 = 107 MHz

$\Delta \phi = \frac{4 \pi \Delta f}{c} (l_{1} - l_{2})$

Frequency sweep calculated from average of first 4 interference cycles as this is the portion of the sweep where most of the spectra were collected. $\frac{\Delta f}{\Delta t} = 1.67x10^{11} \frac{Hz}{s}$

l1 = 47mm

l2 = 421mm