Specific Process Knowledge/Back-end processing/Laser Micromachining Tool/fluence

Fluence definition

The fluence produces by a laser is, by definition, the energy delivered by a laser pulse ($E_{pulse}$) per surface unit ($S$) and it is given in J/cm2.

The function $E_{pulse}$ is defined as :

$E_{pulse}={\frac {\overline {P}}{f}}\,$

Where ${\overline {P}}$ (average power) is measured with the laser sensor power measurement (see manual,section 5.3) and the repetion rate (Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle f} ) is set in the parameter file under " laser frequency".

The fluence is therefore determinated as such :

Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle Fluence = \frac{E_{pulse}}{S}\,}

The theoretical spot sizes ($S$) can be found here

Fluence results measurement

Fluence result for IR wavelength (1064nm, F255mm)	Fluence result for green wavelength (532nm, F255mm)	Fluence result for UV wavelength (532nm, F255mm)