Modular laser apparatus

A laser apparatus comprising:

• a plurality of laser modules each generating an individual final laser line in a working plane, said laser modules being juxtaposed so that the individual final laser lines generated by the modules combine into a combined final laser line, each of the laser modules comprising:
• at least one means for generating a first laser line;
• and
• a means for shaping the first laser line into the individual final laser line,
• wherein the means for shaping the first laser line into the individual final laser line comprises a first linear array of microlenses, a convergent lens, and a second linear array of microlenses placed in the focal plane of the convergent lens, such that the individual final laser line generated by each laser module has, in the working plane, a power density profile with a width (L90) at 90% of a maximum power density and a width (L10) at 10% of the maximum power density, a ratio L90/L10 being between 1/15 and 1/5, the laser modules being juxtaposed so that the individual final laser lines generated by the modules combine into the combined final laser line having a total length longer than 1.2 m but less than an infinite length.