The optical signals of wakes stimulated in laboratory are analyzed and calculated mainly by using MATLAB tools of filter,disperse Fourier transformation (DFT),and statistic semaphore managing etc.The optical semaphores with and without bubble film are much different on the point of energy.Filter can only be used to manage the signals as pretreatment which needs to be treated more in order to practice.Results of DFT under various pressures are different that provide a clew for estimating wakes of different speed and age.By Chirp z transformation,which can provide visual graphs and a proper way to manage graphs,it is possible to confirm the characteristic of optical signals for detecting ship wakes.