Optimization of resonant cell design for optoacoustic gas spectroscopy (H-type).

The design and certain basic characteristics of a new type of optoacoustic device (cell) are described. Initial experimental data using a CO(2) laser operating in the 9-10-microm wavelength region demonstrated sufficient sensitivity to measure the absorption due to SF(6) in the air at a concentration of one part in 10(11). Acoustic Q's were demonstrated in excess of 1800. The general expression for the optoacoustic pressure variations inside the acoustical resonant cavity is given.