The high technology company TRUMPF, based in Ditzingen near Stuttgart, Germany, has put on another impressive show at this year’s Photonics West, one of the most important optics and photonics conferences in the United States: The 2017 edition of the research-focused event is taking place from January 31 to February 2 in San Francisco, California. TRUMPF is focusing on showcasing its most promising solutions for emerging technologies in the fields of research, additive manufacturing and microprocessing. As well as its TruPrint 1000 3D printer and the latest model of the TruMicro 2000 ultra-short pulse laser, the company is also presenting its Dira 200-5 laser amplifier. Based on laser beam sources that deliver high-energy picosecond pulses combined with high repetition rates, the Dira product range has been specially developed for applications in the research sector.
One of the main uses of these systems is to pump optical parametric amplifiers. They open up the possibility of generating femtosecond pulses with just a few oscillations of the electric field, generally referred to as “few-cycle pulses.” These can then be used by scientists to produce even shorter pulses in the attosecond range. To give some idea of the scale involved, one attosecond is a billionth of a billionth of a second. Scientists working on basic research in the realms of medicine, biology or chemistry, for example, can use these attosecond pulses to capture and investigate the highly dynamic movements of electrons on a molecular scale. “Our goal is to help scientists carrying out basic research conduct experiments more efficiently by providing laser systems that offer both high energy output and high repetition rates,” says Knut Michel, Managing Director of TRUMPF Scientific Lasers, a joint venture between TRUMPF and attosecond researcher Professor Ferenc Krausz, who works at the Max Planck Institute of Quantum Optics and the University of Munich.
So what is the technological secret behind optical parametric amplifiers? The entire system is modular, comprising a disk laser as a pump source (in this case the Dira), a titanium sapphire oscillator as a seed laser, the multistage optical parametric amplifier (OPA) system itself, and a synchronization unit. The seed pulse is amplified in multiple stages. Inside nonlinear crystals, the pump and seed pulses are spatially and temporally superimposed with femtosecond accuracy. Amplification is performed using a frequency mixing process known as parametric amplification, in which energy is transferred from the pump pulse to the seed pulse.
In a particularly encouraging development, the Dira 200-1 – the flagship of the Dira range and the big brother of the Dira 200-5 – was recently nominated for the Prism Award in the “Scientific Lasers” category, the winner of which will be announced on February 1, 2017 at Photonics West. “The fact that our laser amplifier has been selected from among so many innovations and shortlisted for the Prism Award is a tremendous honor and exactly the kind of success we were looking for,” says Michel.
Compact 3D printer, flexible picosecond laser
TRUMPF is also pinning significant hopes on additive manufacturing technology, and the company is presenting one of the systems from its range of 3D printers at Photonics West. The TruPrint 1000 is a compact, all-round 3D printer that offers economical manufacturing of fist-sized parts with a maximum height of 100 millimeters and a maximum diameter of 100 millimeters. The TruPrint 1000 uses a process known as laser metal fusion (LMF). This involves using a laser to build up metal powder layer by layer in the powder bed to form whatever part is required, with the data taken straight from 3D CAD software. This technology is particularly suitable for geometrically complex parts – especially those with internal channels and cavities – as well as for cost-effective production of single parts and small batches.
The flexible and versatile TruMicro 2000 picosecond laser is another highlight at this year’s Photonics West exhibition. Combining extremely short laser pulses of between 0.4 and 20 picoseconds with a high pulse energy of 20 microjoules, this ultra-short pulse laser paves the way for a process known as “cold processing.” The moment material struck by a laser pulse registers the onset of thermal processes, it is immediately vaporized. The TruMicro 2000 is designed for a broad range of industrial applications, ranging from high-quality metal engraving to the cutting of extremely thin films and corrosion-free marking of medical devices and chrome-plated plastics. Even when faced with medical devices made from highly reflective materials that are cleaned and sterilized on a daily basis, this system can create high contrast marks that remain corrosion free.