Material-Friendly Marking of Ophthalmic Lenses with Deep-UV Lasers

Imprinting tiny brand logos and providing miniaturized functional inscriptions on hard and transparent high value parts such as ophthalmic lenses and blanks requires a material-friendly and high-resolution marking and engraving tool. The short 193 nm pulses of excimer lasers eliminate the widely-known problems of cracking and melting which are due to thermal load effects of longer wavelength lasers. The good absorption i.e., the low optical penetration depth of the 193 nm wavelength in optically transparent glass and plastic substrates prevents bulk heating and delivers cold and precise marks and engravings on a micron scale.

Compact, high-repetition rate excimer laser sources which are used by thousands in LASIK vision correction have recently emerged as the enabling technology in marking and engraving of ophthalmic lenses due to their short 193 nm wavelength. The nanosecond width deep-UV pulses of the excimer laser selectively remove transparent material such as polymers and glass with unprecedented accuracy and resolution unachieved by the thermal interaction of long wavelength lasers. Excimer lasers deliver their cold pulses fast and precise with up to 500 Hz, ensuring excellent repeatability and process control in marking and engraving of hard and transparent substrates.

Over the last 5 years, leading manufacturers have been moving their ophthalmic lens production to 193 nm excimer laser based marking and engraving for two reasons. First, marks and engravings at 193 nm are superior in quality and do not bear the risk of collateral damage around the mark thus creating higher yield and back-end savings. Second, excimer laser systems have entirely matured in the demanding refractive surgery market and have become extremely user-friendly and widely accepted in demanding medical markets.

www.coherent.com/excimer

Product Marketing Manager: ralph.delmdahl@coherent.com;
PR Europe /MARCOM Excimer: petra.wallenta@coherent.com