157 nm laser facility opens its doors

01 May 2008

An open-access laboratory will allow researchers to exploit the benefits of 157 nm laser light on a pay-as-you-go basis.

The first facility in the UK to offer laser machining services at 157 nm is now up and running at Cardiff University's School of Engineering. The open-access Xtreme Laser Facility could prove particularly useful for industrial microfluidic and lab-on-a-chip applications.

Lab-on-a-chip

"As far as we are aware, there is no-one else in the UK with a commercially available 157 nm laser," David Barrow from Cardiff University told optics.org. "This wavelength allows you to machine 2 µm holes with a resolution of 2 nm in UV transmissive materials and achieve a very good optical finish."

Although UV transmissive materials such as fused silica, Teflon AF and polyetheretherketone (PEEK) are traditionally very hard to machine, they are ideal for industrial microfluidics.

"Chemistry is often done using UV absorption and you have to ensure that the channels are machined with an optical finish and that the material is solvent resistant," explained Barrow. "Another interesting point is that fused silica can undergo a phase transition and will scatter light differently after you have machined it. This transition does not occur at 157 nm."

According to Barrow, the 157 nm excimer laser emits nanosecond pulses at a repetition rate of 200 Hz. The facility is also home to a femtosecond Ti:sapphire laser that operates up to 5 kHz. The beam lines for both lasers have been engineered so that the final laser spots are only inches apart.

"There is an offset of two inches between the two laser spots," commented Barrow. "You can machine a material using both lasers, although not at the same time, without moving the workpiece. When you have finished with one laser, you can add the 2 inch displacement into your CAD file and then continue machining."

As well as the Xtreme Laser Facility, Cardiff's School of Engineering has a microscopy lab that is available for use on a pay-as-you-go basis as well as a dedicated microfluidics lab for both industrial and academic projects.

For more information regarding access to the facility, e-mail barrow@cf.ac.uk

Author
Jacqueline Hewett is editor of Optics & Laser Europe magazine.