Diode laser spectrometer for multi-component gas analysis

Abstract

With the development of lead chalcogenide diodes, tunable IR laser sources have become available, opening new ways for highly selective gas analysis. This is mainly due to their sub-Doppler linewidth of the order of 10−4 cm−1, making derivative and integrative spectroscopy techniques possible. In this paper the state of the art of the lead chalcogenide diode lasers is briefly reviewed and development trends leading to improved laser properties are discussed. A modular diode laser spectrometer capable of single or multicomponent gas analysis is presented and the principle of integrative spectroscopy using pulsed diode lasers is explained. The properties of the integrative spectroscopy technique are demonstrated for the case of CO measurements at various temperatures and pressures.With the development of lead chalcogenide diodes, tunable IR laser sources have become available, opening new ways for highly selective gas analysis. This is mainly due to their sub-Doppler linewidth of the order of 10−4 cm−1, making derivative and integrative spectroscopy techniques possible. In this paper the state of the art of the lead chalcogenide diode lasers is briefly reviewed and development trends leading to improved laser properties are discussed. A modular diode laser spectrometer capable of single or multicomponent gas analysis is presented and the principle of integrative spectroscopy using pulsed diode lasers is explained. The properties of the integrative spectroscopy technique are demonstrated for the case of CO measurements at various temperatures and pressures.