TRUMPF demonstrates 4kW high-brilliance direct-diode laser

Laser and laser system manufacturer TRUMPF (Ditzingen, Germany) unveiled its TruDiode 4001.5 technology demonstrator at the LASER World of PHOTONICS 2017 trade fair (held June 26-29 in Munich, Germany). Based on dense wavelength multiplexing (DWM) technology, the 4kW direct-diode laser offers 5 mm/mrad beam quality, enabling connection to a fiber cable with a 150µm core diameter. Commercially available direct-diode lasers in the high-power segment typically have beam qualities between 30 and 50mm/mrad, and are used with a 600µm laser light cable.

Direct-diode lasers are predominantly used for soldering, heat conduction welding, and surface processing, as these applications do not require high beam quality. But by using the new DWM technology, the company can generate a multiplexed laser beam with high beam quality by combining the outputs from individual diode emitters.

"We use diodes that emit at different wavelengths. The light from the diode emitters is focused onto a diffractive optical element, which combines it into a single laser beam," says Stefanie Feuchtenbeiner, part of the TruDiode product management team at TRUMPF.

Although the unit at LASER World of PHOTONICS 2017 was a 4kW system, the company's initial plan is to develop a DWM TruDiode laser with 1 or 2kW output. With 5 mm/mrad beam quality, the direct-diode lasers have utility in deep-penetration welding and remote welding. They also eliminate the need for a converting medium such as a disk or fiber.

Much of the developers' focus now is on making further advances in diode cooling and diode bar efficiency. Combined with the DWM technology, this will further accelerate the evolution of the overall laser design.

For more information, please visit www.trumpf.com.