Figure 3

A comparison of two transfer functions as seen in the complex plane. The hue and the brightness correspond to the phase and magnitude, respectively. (a) The transfer function \(T(z) = \frac{ e^{- z} - r}{1-r e^{- z}}\) corresponds to a cavity with \(r = 0.8\) and \(\tau = 1\). (b) The transfer function \(T(z) = \frac{ e^{- z} - r}{1-r e^{- z}} e^{-z}\) in addition to a cavity augments a delay of length τ in sequence with the original cavity system.