March 2001 Ultra-fast laser facility puts Galway Centre at the

The National Centre for Laser Applications (NCLA) NUI, Galway has just opened a new state-of-the-art laser processing facility. The new laboratory is built around a femto-second laser system, supplied by Clark MXR of the US. This is only one of four similar systems installed in laboratories around Europe and places the NCLA at the forefront of the new science of ultra-fast laser processing of materials.

"This new laser will allow us to provide this cutting-edge technology to Irish companies for the first time", according to Dr Gerard O Connor, manager of the NCLA. "The first industrial research project based on this new technology has just been agreed between the NCLA and a leading global manufacturer of micro-components."

The NCLA is Ireland s centre of excellence in laser technology, working closely with Irish industry on the development of new production tools and techniques based on laser and optical systems. Laser technology is successfully employed in a large number of industries, from drilling and cutting of engineering materials, to precision marking and welding of advanced polymers.

"Lasers are also a key enabling technology in the automation of high precision industrial processes, " explains Dr. O Connor. "Many Irish companies, both indigenous and multi-national, in sectors ranging from electronics to medical devices, benefit significantly from the improved product quality, greater efficiency and higher throughput, which laser tooling can provide". The medical device manufacturing sector is one of the most active in the uptake of laser technology and the NCLA provides much support in terms of research and development services to this sector and runs a successful conference each year for this industry. Galway is now acknowledged as the European Centre for medical device manufacturing, with many thousands employed in companies such as Boston Scientific and Medtronic AVE.

Femto-second lasers are an exciting new technology in the field of materials processing applications. "The technology is based on the generation of a stream of extremely short, high intensity light pulses, each lasting for only a few hundred femto-seconds. (A femto-second is equal to 10-15 of a second, or a million-billionth of a second!)," explains Dr. O Connor. "The key benefits of such ultra-short pulses lie in their ability to deposit energy into materials in a very short time interval, offering significant advantages over conventional laser sources in high-precision applications such as micro-machining, micro-drilling and ultra-precise cutting."

Materials processing with femto-second lasers is also largely independent of the optical properties of the material, which opens up the possibility of processing transparent materials like glasses and highly reflective and conductive materials such as aluminium and copper which have traditionally been unsuitable for laser machining. "Femto-second lasers are facilitating 21st century advances in science and technology, enabling the machining of the smallest precision features in biological and man-made materials," according to Dr. Jonathan Magee, a senior engineer at the NCLA.

As the energy is transferred from the laser beam into the material, the temperature of the material rises rapidly above its boiling point, where it vapourises. This process is called ablation. "With conventional laser processing techniques, the heat is conducted quickly away from the absorption region before ablation occurs, leading to melting of the material over a larger area. This results in a lower precision and quality of the laser processed parts," says Dr. Magee.

The femtosecond system located at NUI, Galway consists of three laser sources in a single table-top system. These lasers are referred to as the semiconductor seed laser, the YAG pump laser and the titanium-sapphire amplifier laser. The system will deliver up to one thousand ultra-short pulses per second and the duration of the pulse can be varied from 180 to 1000 femtoseconds. "This is an exciting development for the NCLA and we look forward to giving many Irish companies the opportunity to develop new products and processes using this new facility" says Dr. O Connor.

Information from: Máire Mhic Uidhir, Press Officer, Tel. 091 750418