Lasers

SPI Infra-Red Fibre Lasers

Two fibre laser systems, both controlled by in-house software and mounted on mobile racks are used interchangeably between the two mass spectrometers.

One fibre laser is an SPI 20W, 1062nm wavelength laser is used as a continuous wavelength laser and can be controlled in fine increments to allow step-heating and total fusion of the sample or, due to its narrow beam, melting of small spots (beam diameter approx. 50µm).

The second laser system is also an SPI fibre laser, with a 25W max power and wavelength of 1050-1250nm. This system can be used as continuous beam or in a pulsed mode and is again used for step-heating and single grain fusion experiments.

Photon Machines ArF excimer laser (excite)

A photon machines excimer laser with a 193nm wavelength is used for in situ dating work. This 12mJ, 2W, 300Hz system has an HD camera system and high magnification allowing resolution to 2µm features. The homogenisation of the laser beam allows uniform flat ablations with sufficient power to ablate all minerals.

We use this laser system to do detailed in situ studies, measuring spot diameters less than 40µm (if the grain contains enough argon!).