Abstract: A laser system comprises a reflective chamber capable of housing a laser medium and at least two laser diodes emitting light at different respective wavelengths into the reflective chamber. The wavelength of each respective laser diode may be selected to minimize fluctuations in absorption by the laser medium of light emitted by the diode bars as the wavelength of each respective laser diode changes due to changes in an operating temperature of the laser system. The wavelength of each respective laser diode may be selected such that absorption by the laser medium of the wavelength of light emitted by one laser diode increases and absorption by the laser medium of the wavelength of light emitted by another laser diode decreases as the operating temperature changes within a predefined range.

Abstract: A method for introducing a known concentration of at least one species of ions into the surface or near surface of a substrate can be employed as a calibration technique prior to subsequent surface or near surface measurement. The method involves the introduction of a removable layer onto the surface followed by ion implantation which is performed to provide a known concentration of implanted ion at the interface between the removable layer and the surface. Subsequent to removal of the removable layer, the surface can be subjected to determination of elemental concentrations at the surface or near surface levels by techniques such as total reflection x-ray fluorescence or secondary ion mass spectrometry.