One of the options for personalising a passport or identity card, is laser engraving of the polycarbonate card or data page. The laser can engrave the photograph, the personal data, the signature and the MRZ data of the document holder.
What is laser engraving?
Laser engraving is a personalisation technique where a laser sensitive polymer layer inside a polycarbonate data page or card absorbs the energy of a focused laser beam at the right wavelength. This results in the decomposition of the polymer around the laser focal point to produce a darkened area. The laser written information is located inside the card body and laser engraving is therefore considered to be forgery proof.
Why use a fiber laser?
To achieve carbonisation of the substrate, the laser beam must have certain characteristics. Nowadays, Ytterbium Fiber doped lasers are used for laser engraving. A fiber laser has a very long lifetime expectancy, roughly equal to other electronic components. A fiber laser does not need a complex mechanical setup; the beams are simply aligned inside the fiber. Therefore it is not sensitive to optical misalignment and it is very stable. This type of laser does not need constant adjustments. A fiber laser is a maintenance free laser. Another benefit of the fiber laser is that it operates at higher frequencies, meaning that the personalisation speed could increase.
IAI was the first personalisation system supplier to use a fiber laser for laser engraving. Where other suppliers are just now offering fiber lasers for the engraving, IAI has been building its knowledge and expertise on this type of lasers since 2007.
Benefits of IAI’s laser engraving technology
Because IAI does not use a standard fiber laser engraving system available in the market, but developed its own laser head and software, IAI laser engraving technology has some distinct benefits over our competition:
High accuracy – IAI can achieve a very accurate beam positioning because we have developed our own laser head. This results in very tight lines and a highly accurate return position. IAI can achieve a high consistency over all personalised passports.
Sharp images – The sharpness of an image is determined by a combination of spot size and resolution. IAI has optimized its spot size for a resolution of 600 dpi, resulting in sharp, high quality photographs without the need of photo-enhancement software.
Perfect greyscales – Because IAI developed its own laser head and RTC software, IAI has full control over the laser power. This is needed in order to create perfect greyscales for each passport or card material. IAI tests the material by engraving it at a range of power levels and determine maximum laser power needed for that specific material (when a spot turns black without blistering). Then, the 256 greyscales of the engrave image are distributed over the settings. This results in a perfect greyscale distribution from pure white to black without distinctive transitions. This is impossible with a standard laser engraving module available in the market.
Forensically identical output – As every laser differs a little bit in power, it is necessary to make very small adjustments between the lasers. Every laser can be calibrated so, that they create exactly the same greyscales, resulting in forensically identical passports or cards when produced on different laser systems. Each laser has its unique settings and parameters. IAI uses an advanced optical measuring tool to determine these settings and parameters. Once again, this is impossible to do, if one does not have full control over the laser power.
No back reflection – The IAI laser does not suffer from reflection that could cause white spots in a photograph or text. Even if an entire data page was to be filled with one shade of grey, it would still be completely even.
Constant performance over time – The highly stable laser and optical system provide a constant performance. The greyscales do not deteriorate during the day once the system is warmed up. The laser does not degenerate during the life time of the system. This means that the variations in output quality remain limited to an absolute minimum.
Special applications – Unlike when using standard laser modules, IAI controls the complete engraving process from A to Z, because IAI has developed its own software and laser head. This enables us to do special features or applications for our customers. IAI engineers have a lot of knowledge and expertise in the application of laser- and optical technology, as this is our core competence.
