Ultrafast lasers—including femtosecond and picosecond lasers—are ideal for precision micromachining applications, such as processing semiconductors, flat panel displays and various thin-film materials.

Applications may include:

Ultrashort Pulse Processing

Thanks to short pulse widths and high repetition rates, femtosecond lasers excel in applications that have traditionally utilized nanosecond lasers.

When laser pulses are a few picoseconds or less, material interaction occurs so quickly the heat doesn’t have time to travel outside the event zone. With the right laser, optics and settings, this eliminates the heat-affected zone in material processing applications—enabling you to:

• Etch metals and ceramics with the same high level of detail found in acid etching
• Eliminate the post-processing associated with nanosecond lasers
• Cut thin metals with no raised edges on top or bottom surfaces
• Process materials with no discoloration halos around cuts or engravings

Femtosecond lasers depend less on the wavelength than nanosecond lasers for processing materials like polymers, glass and ceramics due to the multiphoton absorption of ultrashort pulses. Multiphoton absorption can bridge large band gap energies that normally require the high photon energies of short wavelength lasers. Short wavelengths may still be required even with ultrashort lasers if small spot sizes are required. These lasers also typically have high repetition rates—achieving high processing speeds.

Laser Marking Stainless Steel

The coupon on the left is the picosecond mark. Notice that it has a flatter black appearance and consistent contrast even when viewed at an angle. Ultrashort marking creates nanostructures in the surface that scatter and trap light—imparting a dark contrast on the metal surface. You can use this same process to mark bare and clear anodized aluminum as well.

Studies have shown that this mark is extremely durable, maintains much of the original chromium oxide layer and doesn’t diminish corrosion resistance. For critical applications, corrosion resistance can be further improved with passivation. For coated stainless steel, preliminary testing indicates that marking takes place without coating removal.