Method to Determine Length and Starting Point of Waveform Frame from Chaos Time Series in Sensing Applications

We propose a novel method to determine the length and starting point of a waveform frame from a chaos time series in sensing applications. Using similarity of adjacent frame waveforms of an SOA fiber ring laser, we obtain quasiperiodic auto-correction of a chaos waveform, with its quasiperiod equal to the frame length. We study the one-to-one correspondence between positions in a fiber ring and time points in a frame. According to periodicity of self-pulse trains and pseudo-randomness of chaos, we can reveal the repeatedly occurred but hidden self-pulse train by superimposing multiple frames of the chaotic waveforms. Occurrence of self pulse coincides with the frame´s starting point. Experimental results show effectiveness of the method. The frame length can be determined by a chaos time series that is slightly longer than one frame. The more the chaos frames are superimposed, the more accurate the frame´s starting point can be determined.