Trace Analysis In Gases By Laser Induced Schlieren Technique
Original Publication Date: 1979-Mar-01
Included in the Prior Art Database: 2005-Feb-20
Highly sensitive impurity trace detection is based on optical calorimetry using spectral coincidences between absorption lines of molecules and laser emission lines. A first laser beam is absorbed by pollutants which creates a change of the refractive index in the gas because of local heating. This change is monitored by a second laser beam with a different wavelength intersecting the first laser beam.