A highly versatile copper vapour laser (CVL) micro-machining system, supplied by Oxford Lasers, forms the centrepiece of CUE's micro-machining laboratory.
The fundamental wavelengths of the laser are 511 and 578 nm, which are ideal for cutting metals, ceramics and many other hard materials. A frequency doubling crystal allows the production of deep ultraviolet radiation at a wavelength of 271 nm for the machining of plastics, polymers and single crystal materials.
This laser system is used to develop ultrasonic transducers for a very wide range of fields including biomedicine, non-destructive testing (NDT) and sonar. The electron microscope image shows sections of a lead zirconate titanate (PZT) plate diced using the CVL. The centre to centre pillar spacing is 65 µm and the kerf width is 13 µm. The diced material has been used to fabricate a 170 µm thick transducer for ultrasonic reception at frequencies close to 10 MHz.