Versatile integrated tunable diode laser system for high precision: application for ambient measurements of OCS

A versatile and integrated tunable diode laser system for high precision measurements of the important sulfur gas carbonyl sulfide is described. We explicitly address some of the-major factors affecting tunable diode laser measurement precision as well as accuracy and have implemented a number of new features for increased system control and versatility. The system described herein provides the capability for measuring ambient concentrations of this gas with a precision in the range from +/-0.3 to +/-1% over time periods of many hours. Such a precision provides us with an important new capability for measuring true spatial and temporal variations of carbonyl sulfide in the atmosphere.