Before quantum cascade lasers were developed, the mid-infrared spectrum was served by semiconductor lead salt lasers based on Pb x Sn 1− x Te or Pb x Eu 1− x Se y Te 1− y.Lead salt lasers ...

Methane, like carbon dioxide, is a significant ... Firstly, the absorption spectra of many gases in the conventional infrared wavelengths often used for detection overlap and are interfered ...

Alongside carbon ... carbon dioxide. However, detecting and monitoring these pollutants is challenging for two reasons. Firstly, water vapor interferes and overlaps with the absorption spectra ...