The principle of laser cleaning

It mainly includes the following aspects:

Absorption effect: The energy of the laser can be absorbed by contaminants on the surface of the target, causing the contaminant absorption point to heat up, causing thermal expansion and melting. This thermal expansion creates thermal pressure, causing the adhesion of the contaminants to the substrate to momentarily decrease, causing the contaminants to separate from the substrate.

Plasma effect: When the power density of the laser beam is higher than the threshold of the material, plasma is generated. Plasma is a high-energy electromagnetic field composed of positively charged ions and free electrons, which can strip the chemical bonds between pollutants and substrates or dissociate the molecular structure, thereby cleaning the pollutants on the surface of the target object.

Evaporation effect: When the laser beam irradiates the surface of a pollutant. The light energy is absorbed by the pollutant and heats the pollutant to a high temperature, causing its temperature to rise above the evaporation temperature, causing the pollutant to evaporate. The evaporation effect can completely remove contaminants without damaging the substrate. Photochemical reaction: The laser reacts with the chemical substances on the surface of the target object. Thereby changing the chemical properties and achieving a cleaning effect.

Blasting effect: During laser cleaning, due to the instantaneous high energy density. Contaminants will undergo a blasting effect due to thermal expansion. This blasting effect causes contaminants to rapidly break and fall off the surface in a short period.