Cleaning system and method for operating the cleaning system

A method for cleaning of cavities filled with a liquid using an electromagnetic radiation system, wherein the electromagnetic radiation system comprises a radiation source for generating a radiation beam and an optical delivery system for delivering the radiation beam, wherein the delivery system includes a treatment handpiece and an exit component, and wherein the method comprises the following steps:

• using the treatment handpiece and the exit component for irradiating the liquid within a cavity with the radiation beam,
• choosing a wavelength of the radiation beam for significant absorption of the radiation beam in the liquid, wherein significant absorption is absorption of electromagnetic radiation such that bubbles are generated within the liquid,
• operating the electromagnetic radiation system in pulsed operation with at least one pulse set containing at least two individual pulses, wherein a first pulse of the pulses is followed by a second pulse of the pulses with a pulse repetition time,
• generating a first vapor bubble within the liquid by means of the corresponding first pulse such, that the first vapor bubble oscillates in an expansion phase from a minimal volume to a maximal volume and in a subsequent contraction phase from a maximal volume to a minimal volume,
• generating a second vapor bubble within the liquid by means of the corresponding second pulse at a location different to the location where the first vapor bubble is present at the time of generating the second vapor bubble,
• adjusting the pulse repetition time such, that an onset time of the second vapor bubble is within the first contraction phase of the first vapor bubble, when the first vapor bubble has contracted from its maximal volume to a size in a range from about 0.7 to about 0.1 of the maximal volume.