Rigorously, the oscillation is periodic only at u = v = 0 . Indeed, in the realization of the Toda oscillator as a self-pulsing laser, these parameters may have values of order of 10 − − 4 ; during several pulses, the amplitude of pulsation does not change much. In this case, we can speak about the period of pulsation, since the function x = x ( t ) is almost periodic.