Optical-feedback cavity ring-down spectroscopy measurements of extinction by aerosol particles.

Optical feedback cavity ring-down spectroscopy (OF-CRDS) using a continuous wave distributed feedback diode laser at 1650 nm has been used to measure extinction of light by samples of monodisperse spherical aerosol particles <1 mum in diameter. The OF-CRDS method allows measurements of low levels of extinction of incident light to be made at repetition rates of 1 kHz or greater. A statistical model is proposed to describe the linear relationship between the extinction coefficient (alpha) and its variance (Var(alpha)).

Cavity ring-down spectroscopy measurements of single aerosol particle extinction. I. The effect of position of a particle within the laser beam on extinction.

A continuous wave distributed feedback diode laser operating in the near infrared at wavelengths close to 1650 nm has been used to measure the extinction of light by single aerosol particles. The technique of optical feedback cavity ring-down spectroscopy (CRDS) was used for measurement of CRDS events at a repetition rate of 1.25 kHz.