Laser enhanced trace analysis

Two separate projects are presented. The first sought to extend the sensitivity of laser intracavity absorption enhancement applied to fluid samples. The second was directed to improvements of sources of modulated light. Quantitation of absorbance for aqueous samples were accomplished with a detection limit factor for ten better than previously reported. Calibration curves were completed for absorbance ranging from 0.001/cm through 0.00002/cm in a 1 cm cell. Measurement of chemical reaction rates was successfully completed using this device. Light amplitude modulated at 0.01 Hz to 60 MHz and heterodyne modulated at 100 to kHz to 1.2 GHz was produced.