Laser Fab System Increases Machining Speed
OXFORD, England, Aug. 18, 2011 — By combining holographic beam shaping and multiple focal spot generation, University of Oxford researchers developed a method for the adaptive control of multiple focal spot illumination that they say will lead to an increase in the versatility and speed of laser machining fabrication.
Most laser fabrication systems use a single focused laser beam to fabricate material in a sequential fashion. The speed can be increased by using multiple parallel focal spots (using a microlens array), but the disadvantage is that the array of foci is fixed and the foci cannot be controlled independently.
Holographic patterns created by diffractive optical elements, on the other hand, can split the laser beam into many foci. This can be more versatile than using a single focused laser beam, if adaptive diffractive elements such as spatial light modulators are used. However, these suffer from wavelength dependence and chromatic aberration. This, along with other device limitations, restricts the number of focal spots that can be created in parallel.
Merging both the microlens array and holographic methods to create arrays of independently controllable focal spots allows the arbitrary control of large numbers of parallel foci and, according to the researchers, improved laser machining and fabrication.
Isis Innovation, a wholly owned subsidiary of the University of Oxford that manages the university’s technology transfers, would like to talk to companies that develop laser-based manufacturing systems who are interested in developing this new method. A patent application for this invention has been filed in the UK.
For more information, visit: www.ox.ac.uk
- chromatic aberration
- The lens aberration resulting from the normal increase in refractive index of all common materials toward the blue end of the spectrum. The change in image size from one color to another is known as lateral color or chromatic difference of magnification.
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