Software-Controlled High-Resolution Laser Photoacoustic Spectrometer: Techniques and Programs for Measuring and Processing Weak Absorption Spectra of Atmospheric Gases

Abstract

A software-controlled photoacoustic spectrometer designed on the basis of a TEC-520 diode laser (output power 30 mW, coarse tuning range 6060–6600 cm⁻¹, bandwidth ∼5 × 10^–5 cm⁻¹, fine tuning range is 0–2.5 cm⁻¹), WS-UIR laser wavelength meter (relative error Δλ/λ ∼ 10^–8), and resonance photoacoustic detector with a threshold sensitivity of ∼3 × 10^–10 W cm⁻¹ Hz^−1/2 is described, as well as techniques and software developed for measurements and spectra processing. The water vapor spectra are analyzed.