FEMPAR - Deep engraving system for coining dies with femtosecond laser

Challenge

The assessment aims to provide a robust laser source with improved performances delivering pulse energy of 40 µ Joules at an average power of 40 Watts. New solutions will be implemented to improve the engraving process with respect to speed and quality. Another objective is to remove both “step effect” and “weaving effect”, which come from superposition of slices, but to still provide frosting effects on the surface.

Benefit

This innovative laser system will enable Monnaie de Paris (MdP) to produce embossing tools or dies with a better depth resolution compared to the tools used today. The engravers will be able to put sharper details in the design of the numismatic coins. Precise engraving quality is a crucial criterion for the customers of MdP. It also enables important security features, like micro engraving, which cannot be copied by counterfeiters. Moreover, some new surface feature should be obtained with the new system: The "rainbow" effect could be produced and other surface effects will be tested.

Due to the power delivered by the laser the user should be able to reduce the processing time of the dies. The dies’ costs will decrease and the production will be more flexible. The femtosecond lasers have enabled micro-machining of a wide range of materials with great precision. To address industrial markets, processing time must be as short as possible and reliability in harsh environments is paramount.

Achievements

FEMPAR delivers the highest power industrial grade laser source with 500 femto seconds pulse duration. It is built on a robust technology platform that enables the delivery of high power and high reliability on a small footprint. The optional second and third harmonic opens additional areas of application that benefit from the new laser source. The FEMPAR result will most probably lead to a new product that can be used in highly demanding 24/7 applications in industry where power, precision and durability are key for the manufacturing success.