A set of time-resolved photoacoustic laser spectrometers
A.B. Tikhomirov, B.A. Tikhomirov
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, 1, Academician Zuev square, Tomsk, 634021, Russia
Keywords: лазерный оптико-акустический спектрометр, фоновый сигнал, временное разрешение, атмосферный воздух, неселективное поглощение, laser photoacoustic spectrometer, background signal, time resolution, atmospheric air, non-selective absorption
Abstract
A set of photoacoustic spectrometers in order to study the weak aerosol and molecular absorption of laser pulses by atmospheric air in UV, Visible and near infrared spectral regions is designed. The common element of spectrometers is a photoacoustic detector with a temporal resolution of signals and a built-in acoustic hub consisting of two parabolic mirrors. The detector is characterized by a high sensitivity (minimum measured value of the absorption coefficient reaches ~ 10–9 cm–1 at a laser beam radius of 1.5 mm and a laser pulse energy of 50 mJ) and by lack of background signals associated with the absorption of radiation at the inner surface of the photoacoustic cell. Some results of measurements of non-selective molecular and aerosol absorption in gases and air, including non-linear absorption of high-power femtosecond laser pulses are presented.
|
