The industrial laser industry is getting very exciting these days. Almost from the start of the laser industry, CO2 lasers ruled the roost at high powers, but with flashlamp-pumped solid state lasers filling up the lower end of the average power market and taking up some specialized market niches.
Things have really changed in the past ten years. Firstly, sub-500W sealed CO2 lasers came along to take a good position in the lower cost marking and laser machining applications, and in specialised applications where the longer far infrared CO2 laser was essential.
Then diode-pumped solid state lasers appeared on the scene and, as product development continued, frequency-doubled, -tripled and even -quadrupled versions became commercially available. These developments brought new levels of focusability and process control and, at last, lasers started making serious inroads into the micromachining arena in a number of industries.
Direct diode lasers for materials processing were introduced several years ago for low power density applications and are now available at up to several kilowatts. In Germany, exciting progress is being made on disc lasers and these are now available all the way up the power range.
Excimer lasers are still very much around in their specialised niches although diode-pumped solid state lasers have made some inroads into their applications. Pico and femtosecond lasers are also now slowly emerging from research labs.
However, it might be seen as unfortunate timing for the disc lasers that fibre lasers came along when they did in the aftermath of the telecom meltdown in 200/2001.So, there are many different types of lasers, many of them fairly new. As such, the application space for each laser type is not well defined. More interestingly, many of these laser types overlap for many applications. This makes for a very interesting technical landscape.
Over the course of the past two to three years, it has become clear from many technical articles and conference papers that fibre lasers do have real industrial benefits, and are not simply another technically interesting laser technology that occupies only a very small application space in the industry: Femto and pico lasers and perhaps even direct diode lasers may fall into this category. It is now clear that fibre lasers do not fall into this category; they are here to stay, and the discussion is simply how large a slice of the industrial pie are they going to take. Initial estimates are being continually revised upwards and my personal opinion, as a fiber laser proponent, is that within a few years, this will be greater than 50 per cent of the total laser market. This is based not on a market analysis, but on two years in the applications lab using these lasers and familiarising myself intimately on a day-to-day basis with their very surprising processing capabilities.
Tony Hoult.. confident in the future of fibre lasers.
Of course no one laser manufacturer makes all of these different laser types and this means that a degree of OEM bias is inevitable in deciding between laser types for a specific application. Added to this is the fact that industrial fiber lasers are currently only being manufactured by two companies and both of these are relative newcomers to the laser field. Both ourselves (SPI Lasers) and IPG have morphed very rapidly from telecom companies to lead the fibre laser charge. IPG are leading the technology at high average power levels, but the market demands more than one supplier. SPI Lasers is now differentiating itself at lower power levels by providing high quality products at the 200W power level and a 20W pulsed laser.
Apart from processing an ever increasing number of customer applications each week, some of the more surprising processing capabilities of fibre lasers are investigated as short- to medium-term in-house projects. These projects have identified some very interesting non-linear effects. The technical details are for another article, but this non-linear behavior is due simply to the ability of these lasers to comfortably achieve threshold power densities > 100 MW/cm2, while still employing standard off-the-shelf optics. Recent in-house trials have produced very exciting results on machining semiconductor materials that would normally be considered impossible to machine well with continuous wave (CW) infrared fiber lasers. On seeing these results, a 25-year industry veteran is quoted as saying ‘you have just changed all the rules’.
