The observations can be explained as follows: due to the refractive index change at the cavity surface, a minimal focus shift (whose magnitude depends intricately on parameters such as bubble deformation, phase of the oscillation cycle, focusing NA, etc.) along the laser optical axis is conceivable. Nevertheless, if the focus is still located within the cavity, it encounters this cavitation bubble filled with low-density water vapor.23 Water vapor, unlike liquid water, can no longer be assumed to be an amorphous semiconductor,16 so that the ionization energy increases dramatically.23 The increase in the threshold energy required for LIOB inside a cavitation bubble is appreciated to up to six orders of magnitude due to the gas phase inside.34,35 Therefore, the laser pulse energy is not sufficient to induce another optical breakdown; it should be noted that the occurrence of nonlinear absorption effects still cannot be excluded. The determined ratio of about 2 between the transmission signal measured for the second and first pulses can be compared to the transmission values in case of a LIOB in the literature.17,30 The transmission of a 300 fs-laser pulse with a wavelength of 580 nm at 10 times the breakdown threshold equates to 54 to 61% due to an occurring optical breakdown.17,30 Hence, the transmission of the subsequent laser pulse which impinges the cavitation bubble should yield a 1.63- to 1.85-times higher value, if it has a transmission of 100%. Thus, the findings of the presented study are in good agreement with the literature.17,30 However, it has to be mentioned that the 30 does not take into account the focusing angle as well as that the detector position differs from the one in the presented study. The mean value of the central transmission of the third pulse, being decreased compared to the first one, might be traced to a rise in scattering structures like gas bubbles in the course of the pulse sequence.