Understanding the impact of gaseous pollutants on the earth's atmosphere, as well as more and more felt by mankind negative effects of its contamination, result in increasing the level of environmental awareness and contribute to the intensification of actions aimed at reducing the emission of harmful gases into the atmosphere. At the same time, the extensive studies are conducted in order to continuously monitor the level of air contamination with harmful gases and the industry compliance with the standards limited the amount of emitted pollutants. <p> </p>Over recent years, there has been increasing use of cascade lasers and multi-pass cells in optical systems detecting the gaseous atmospheric pollutants and measuring the gas concentrations.<p> </p> The paper presents the use of a tunable quantum cascade laser as a source of the IR radiation in an advanced detection system enabling the trace gaseous atmospheric pollutants to be identified. Apart from the laser, the main elements of the system are: a multi-pass cell, an IR detector and a module for control and analysis. Operation of the system is exemplified by measuring the level of the air pollution with ammonia, carbon oxide and nitrous oxide.
Hazardous chemicals detection systems based on cascade lasers are wider and wider used for monitoring the earth
atmosphere pollution, as well as in the safety apparatus installed in buildings of public services. The main feature of
these systems is a high sensitivity that for the most advanced set ups allows detecting chemical substances at the level of
single ppt (part per trillion).
In this paper, we present a measuring system dedicated to detecting hazardous chemical substances in which
a semiconductor cascade laser has been implemented for the generation of IR radiation. The system operation and
potentialities are exemplified by its application to detecting and monitoring the ammonia concentration in the air.