10 years ago.
LOE's Covert Holographic Mark
Laser Optical Engineering Ltd (LOE), a spin-off from Loughborough University in the UK, has developed a method for using diffractive optics to blaze holograms onto hard surfaces, creating a low-cost method to incorporate small, data-carrying holograms on products, as reported in Holography News[R] of February 2003.
The DOEs, or kinoforms, replace a typical 45[degrees] turning mirror in the laser (CO2or Nd-YAG) to 'transform the beam into previously unattainable novel shapes,', according to John Tyrer, managing director.
A range of standard beam profiles can be produced, but much more complex shapes can be created, including the diffractive pattern for a holographic image. This requires the computer to generate the DOE needed to produce the desired holographic diffraction pattern. The resulting DOE is then etched on to the object as the security mark. To date, the company has produced holograms measuring 1 mm sq with a capacity of 1014--1017 data bits, taking under a second to produce.
In use, a customer would buy or lease from LOE the laser system to install on a production line. LOE would produce the DOE to produce the customer's pattern, and if more than one is required to create different marks it is a brief task to change the DOE in the laser.