Multikilowatt Ytterbium Fiber LaserA line of industrial low-order-mode ytterbium fiber lasers that produce 4 kW of continuous-wave output and that operate at 1060 to 1090 nm combine the power of single-mode monolithic diode-pumped 100- and 300-W lasers. The power is delivered through a multimode fiber 100 to 300 µm in diameter, depending on the power level, and up to 300 m in length. The result of a collaboration among IPG Photonics of Oxford, Mass., and its subsidiaries IPG Laser GmbH in Germany and NTO IRE-Polus of Russia, the lasers can be operated in continuous mode or modulated up to 3 kHz with transistor-transistor logic. They produce consistent power density and beam distribution. The units are excited by single-stripe multimode diodes that are thermally isolated from each other and have an estimated lifetime of more than 100,000 hours. The modular systems measure 60 X 80 X 160 cm and weigh 400 kg. With a wall-plug efficiency of more than 20 percent, they can be air- or water-cooled. The company says the lasers require little maintenance, and are efficient and low in power consumption. The instruments are suitable for high-speed and remote welding, and for high-speed cutting, drilling and surface modification for applications in the automotive, aerospace, chemical, construction, petroleum and shipbuilding industries.