Industrial femtosecond lasers and material processing

Over the last five years, material processing with femtosecond pulses in the range of 300 to 900 fs has gained in popularity. Over the last five years, material processing with femtosecond pulses in the range of 300 to 900 fs has gained in popularity due to the small heat-affected zone (HAZ) and increased energy penetration depth resulting from the high laser pulse intensity. Industrial ultrashort-pulse (USP) diode-pumped solid-state and fiber lasers are now being used to cut foils for flat panel displays, to cut stents, and to drill fuel injector nozzles, as well as for wafer scribing and surface microstructuring. The first industrial use of femtosecond laser pulses for microprocessing dates back to the late 1990s, where titanium sapphire (Ti:sapphire) amplifiers were used to repair lithography masks in integrated circuit fabrication. At that time, the only choice in commercial laser sources were Q-switched, neodymium (Nd)-doped solid-state lasers delivering pulse duration of tens of nanoseconds, and ultrafast Ti:sapphire amplifiers that exhibited pulse durations of 100 fs and provided output power at the 1 W level at 1 kHz (FIGURE 1). The small feature size of the chromium lay...

Video Shows Power Isn’t Everything In Laser Engraving

When it comes to power tools, generally speaking more watts is better. But as laser maestro [Martin Raynsford] shows, watts aren’t everything. He shares a brief video showing his older 100 W laser being handily outperformed by a newer 30 W machine. Shouldn’t the higher power laser be able to do the same job in less time? One might think so, but wattage isn’t everything. The 30 W laser engraves and cuts a wooden tile in just under half the time it takes the 100 W machine to do the same job, and with a nicer end result, to boot. Why such a difference? Part of the answer to that question lies in that the newer machine has better motion control and can handle higher speeds, but the rest is due to the tubes themselves. The older 100 W machine uses a DC-excited (big glass water-cooled tube) CO2 laser, and the newer 30 W machine uses an RF-excited laser that looks a bit like a big metal heat sink instead of oversized lab glassware. Both tubes output what is essentially the same beam, but the RF tube is overall capable of a more refined, more stable, and more finely focused point than that of the glass tube. Since engraving uses only a small fraction of even the 30 W laser’s power, the ...

When it comes to power tools, generally speaking more watts is better. But as laser maestro [Martin

When it comes to power tools, generally speaking more watts is better. But as laser maestro [Martin Raynsford] shows, watts aren’t everything. He shares a brief video showing his older 100 W laser being handily outperformed by a newer 30 W machine. Shouldn’t the higher power laser be able to do the same job in less time? One might think so, but wattage isn’t everything. The 30 W laser engraves and cuts a wooden tile in just under half the time it takes the 100 W machine to do the same job, and with a nicer end result, to boot. Why such a difference? Part of the answer to that question lies in that the newer machine has better motion control and can handle higher speeds, but the rest is due to the tubes themselves. The older 100 W machine uses a DC-excited (big glass water-cooled tube) CO2 laser, and the newer 30 W machine uses an RF-excited laser that looks a bit like a big metal heat sink instead of oversized lab glassware. Both tubes output what is essentially the same beam, but the RF tube is overall capable of a more refined, more stable, and more finely focused point than that of the glass tube. Since engraving uses only a small fraction of even the 30 W laser’s power, the ...