Farmington, CT--In laser card marking, the pulsed energy produced by a laser is applied to the plastic (e.g., polycarbonate) card creating characters, images and even photographs via a set of steering mirrors and/or a translation stage. The transferred laser energy heats or carbonizes the card material. If the pulse energy exceeds a certain threshold a color change occurs from white to black. Careful control over the laser pulse energies can be used to create very fine, consistent lines/characters and also to produce shades of grey (grey scaling). The latter is essential in producing detailed images and photographs.
The laser's pulse energy influences the diameter of each overlapped spot and thus the width and continuity of lines formed using a series of pulses. In the same way, pulse energy also controls the darkness of any given pixel. This is critical in applications requiring grey scaling and/or color marking. The laser pulse energy must be stable enough to remain above the marking threshold but below damage thresholds. Multiwave PhotonicsMultiwave Photonics (www.multiwavephotonics.com) pulsed fiber MOPA offers extreme pulse-to-pulse energy stability over it's entire operating range matching and in many cases exceeding the pulse-to-pulse stability offered by today's solid-state lasers.
Controlling the energy of each single pulse allows control over the darkness of each pixel in grey scaling applications. Multiwave's unique all-fiber pulsed MOPA design architecture and advanced control electronics, allowing the user to vary the energy of each pulse without changing the pulse width, in real time. This pulse-to-pulse energy control can be performed even at high repetition rates. Whereas, Q-switched lasers (DPSS, LPSS, and fiber) may experience an intrinsic coupling of laser pulse width to the output pulse energy, i.e., the pulse width and thus peak power changes with changing pulse energy.
For many years now, plastic card marking applications have been served by DPSS and LPSS Q-switched lasers. Modern fiber lasers can now match and in most cases exceed the performance of these incumbent solid-state lasers and are more economical and reliable. Plastic card marking is yet another example of where fiber lasers are displacing conventional technology.
Contact Andy Held (email@example.com) at Multiwave Photonics, Farmington, CT for more information.