Fiber Lasers Cut Into New Industries

David L. Shenkenberg, Features Editor, david.shenkenberg@laurin.com

In all lasers, a substance is stimulated to make the laser beam. This substance is called the active gain medium. In fiber lasers, the active gain medium is the optical fiber itself, and the glass, plastic or quartz fiber is doped with rare-earth elements such as erbium, ytterbium, neodymium, dysprosium, praseodymium and thulium. Erbium- and ytterbium-doped fibers are most common.

Fiber lasers have been used mostly in industrial materials processing. One of the most important technical advantages that they provide is the flexibility and slim profile of a fiber that can be integrated anywhere from an assembly line robot to the back of a Humvee. The flexibility of the fiber also allows factory workers to cut materials with finesse. These are just a few reasons why fiber lasers could replace bulky CO₂ lasers, which take a brute force approach to cutting.

According to Optech Consulting of Tägerwilen, Switzerland, the fiber laser market has been growing by 42 percent on average every year for the past three years, to $300 million in 2008. Materials processing applications consistently account for about 70 percent of the market.

That being said, many factories have been reluctant to replace CO₂ lasers because those lasers have proved reliable for many years. As the saying goes, “if it ain’t broke, don’t fix it.” Smart companies sell these older lasers along with newer fiber lasers, so that they can satisfy all customer preferences.

Fiber lasers are poised to win in the long run because they have distinct cost and operational advantages over older lasers. Factories using fiber lasers have much lower electric bills than those using CO₂. Moreover, CO₂ lasers require helium gas, which is both costly and rare.

Various experts have said that the fiber laser market is contracting because of the global recession. Many industries lack the finances to purchase new lasers right now. The automotive and airline industries are struggling; defense contracts are being reconsidered; electronics are staying on shelves as consumers tighten their belts. This reluctance to buy products has trickled down to sales of fiber lasers.

On the other hand, factory orders as a whole rose in February, and Boeing delivered more planes than last year in the first quarter, both very good signs. Experts say that sales of fiber lasers are resisting the recession more than sales of other industrial lasers because fiber lasers are relatively new and offer advantages that other lasers cannot provide. Moreover, fiber laser sales will increase once the recession has ended and will benefit from targeting industries such as biomedicine and solar cell processing.

Companies move forward

Companies that make fiber lasers include Nufern of East Granby, Conn., SPI Lasers of Southampton, UK, and IPG Photonics of Oxford, Mass.

An IPG laser lets the sparks fly.

In a release, IPG Photonics reported that it made $229.1 million in 2008, a 21 percent increase in revenue compared with the $188.7 million the company made in 2007. The company cited strong growth in materials processing and overseas orders. Aside from its Massachusetts headquarters, the company has manufacturing facilities in Germany, Italy and Russia, and regional sales offices in Detroit, China, India, Japan, Korea and the UK. It is listed on the Nasdaq under the symbol IPGP.

IPG lasers have applications ranging from microelectronics, printing, automotive, medical devices, shipbuilding and aerospace. “The lion’s share of our business is in materials processing,” said Bill Shiner, vice president of the industrial division at IPG. “We’re also involved in medical, telecommunications and government,” he added. Most recently, the company has moved into solar cell processing. Shiner acknowledged “hefty” competitors such as Trumpf and Rofin-Sinar but said, “We’re rapidly taking market share.”

Its lasers range from a few watts to tens of kilowatts in power. “As far as volume, one of our most prolific products is our marking lasers,” Shiner said. Because the company cut its teeth in the telecom industry, its diodes conform to rigid telecom standards.

Its latest additions to its product portfolio are its 10-W pulsed and 15-W continuous-wave 532-nm green fiber lasers. The pulsed laser is designed primarily for solar cell processing, and the continuous-wave for entertainment and solid-state laser pumping.

Some interesting things about the company include that it provides lasers for remote welding, replacing an electron beam application. According to Shiner, some of its units were tested with the Boeing Avenger project, which involves outfitting a laser to a Humvee, the idea being that soldiers someday may fire laser beams at military targets as they cruise in the Humvee. “The reason our laser is in a Humvee is because it’s compact,” Shiner said. The company can pull several kilowatts from a 100-μm fiber core. By comparison, a human hair is 70 μm in diameter.

Acquisitions strengthen positions

Half of Nufern’s business is as a supplier of optical fibers. The company also sells NukW lasers with kilowatt power levels, NuTx lasers for lidar and the NuQ 20-W average power, 10-kW peak power industrial marking lasers. The NuTx lasers are sold at an eye-safe wavelength, and the NuQ lasers have a rapid 125-μs turn-on time. The company sells its lasers mainly for marking and engraving, but it is penetrating into cutting and welding. The company also has a portfolio of intellectual property that it is willing to license.

This Nufern lathe fabricates optical fibers by modified chemical vapor deposition.

“What sets us apart from many other fiber laser companies is that we have a strong background in the US military and defense,” said Bryce Samson, vice president of business development at Nufern. He asserted that this background in defense leads to performance in terms of the output power and the beam quality.

Nufern was purchased a little more than a year ago by Rofin-Sinar Technologies (Nasdaq: GS) of Plymouth, Mich., and Hamburg, Germany. Samson said Nufern may continue to operate as a stand-alone entity, as Rofin-Sinar has done with some of its past acquisitions. However, he said that it is too early to tell because “it’s still in the honeymoon period.”

SPI Lasers recently was acquired by Trumpf, a private company headquartered in Ditzingen, Germany, with an American business unit in Farmington, Conn. Since the acquisition, the two companies have been sharing technical and development information, but the companies will keep their sales operations separate, according to SPI’s vice president of sales John Tinson. SPI will sell lasers below 1 kW in average power for OEM use as well as laser modules for companies that want to sell their own fiber lasers. Trumpf continues to focus on solutions and end users in industry.

An SPI fiber laser cuts silicon.

SPI’s lasers are used primarily for micromachining and medical applications. Its customers mostly do cutting, welding and marking, although the company also has significant market share in drilling, ablation and engraving. The company is pursuing new markets such as solar cells and displays.

The SPI lasers have various features, among them the ability to stabilize the pulse power for sensitive applications such as micromachining. Its pulsed lasers can process materials in continuous-wave mode to 500 kHz, enabling users to process materials as fast as they want.

SPI is expanding its facilities and hiring applications staff. “The fiber laser has by no means reached its market potential, and so it is up to the suppliers to continue to expand the applications envelope,” Tinson said.

Newport sells the Alliant fiber laser, which is in the low- to mid-power range. The company targets primarily fine machining and cutting applications, especially biomedical applications such as processing stents. The main advantages of the laser, according to product manager Scott White, are the reliability and lifetime of the diodes that the company integrates with the ytterbium-doped fiber.