Transmission curves as a function of the phase delay of outputs I₂ and I₃, respectively shown in blue and red, from the star transit simulation experiment, displayed in linear (top) and logarithmic scale (middle). The modified transmission model adapted from Angel & Woolf (1997) and fit to the data is overlaid as a dashed gray line. The fit of the left part of the central broad null by a polynomial function is shown as a black continuous line. The background level is indicated with a dotted magenta line. The bottom plot shows the normalized fit residuals between the blue and gray dashed lines.