When the laser was patented in 1960, it was famously described as “a solution looking for a problem.” Since then, the laser (an acronym for light amplification by stimulated emission of radiation) has found myriad uses in diverse industries, and new applications are being developed all the time.
The market for flat bed sheet metal cutting was initially dominated by YAG lasers that used an yttrium-aluminum-garnet crystal ‘doped’ with rare earth elements (neodymium, ytterbium or erbium). Then came CO2 lasers using carbon dioxide stimulated by electricity. But changes are in the works. Dr. Mark Greenwood, Chief Technical Officer of SPI Lasers:
Up until the turn of the millennium, nearly all industrial lasers used for flat bed cutting of metal were CO2 lasers. Now, I would estimate that 65 to 70% of the lasers in this market are fiber lasers.
Fiber lasers use optical fiber infused with one of these same rare earth elements, namely neodymium, ytterbium or erbium. And like the two previous technologies, fiber lasers combine efficiency and power for large-scale materials processing.
The Rise of Sharper Lasers
For Mark Greenwood, fiber lasers have made inroads into this market because of their great advantages:
They are up to 10 times more efficient than gas lasers, which need cooling systems and require lots of maintenance. They have a shorter wavelength than CO2 lasers, as little as one micron, compared to 10 microns, which means they can be focused on a smaller spot and cut more finely and more quickly.
Fiber-based systems are also more practical because there are no mirrors to adjust or align.
As the light is transmitted through an optical fiber, it can be delivered directly to the point on the material where you want to focus. This makes it easier to use them in robotic applications such as welding on a production line—the optical fiber just moves with the robot.
Other leading names in the field include ROFIN, which last year launched the third generation of its FL Series. The manufacturer claims that these lasers establish a new technological benchmark by generating an output power of 2 kW from just one fiber module. This makes it more compact and easier to integrate into existing cutting systems.
Coherent has introduced an all-new muIti-kilowatt platform (4 kW and beyond) for cutting and welding applications. It says the modular design of its Highlight FL lasers will simplify maintenance and give OEMs the choice of either an off-the-shelf option or building their own custom system.
The market for industrial fiber lasers will grow at a cumulative growth rate of 16% between now and 2019, according to a report by analysts from Technavio.
Demand is rising in sectors other than materials processing. In the oil and gas industry, fiber lasers are proving they can drill at speeds faster than conventional diamond-tipped bits. A big growth area for SPI Lasers is developing fiber lasers for 3D printing in metal. The technology could also play a part in the development of batteries that can store energy from renewable sources.
Unlike other systems, supercontinuum lasers can create a kind of ‘laser rainbow’—a broad light spectrum of several colors. They are used for bio-imaging, semiconductor inspection and metrology.
Jesper Toft Olsen, Product Line Manager at SuperK:
Our supercontinuum lasers can achieve resolutions of 2 microns where before scientists have been working with resolutions of 5 to 10 microns. This means you can use light like ultrasound to generate extremely detailed images. You can look at objects at significantly higher resolutions through normal microscopes. This technology is driving the development of many niche applications in spectroscopy and optical coherence tomography.
Fiber lasers are already capable of slicing through an inch of steel. They are now becoming even more powerful. Systems are being demonstrated that can protect buildings and stadiums from drone attacks. A prototype laser weapon, developed by combining six commercial fiber lasers, has been tested on a US Navy warship in the Persian Gulf. The stuff of Stars Wars is fast becoming reality.