An apparatus for characterizing multilayer samples is disclosed. An intensity modulated pump beam is focused onto the sample surface to periodically excite the sample. A probe beam is focused onto the sample surface within the periodically excited area. The power of the reflected probe beam is measured...http://www.google.co.uk/patents/US5978074?utm_source=gb-gplus-sharePatent US5978074 - Apparatus for evaluating metalized layers on semiconductors
