Measurement and characteristics analyses of spectral ripple in optical-feedback cavity ring-down spectroscopy

To study the mechanism of ripple effect existing in optical-feedback cavity ring-down spectroscopy, data processing method is applied to analyze the typical characteristics of ripple effect, including the period and amplitude, based on the measured data with a 49.1 cm long V-shaped glass ceramics cavity in the different circumstances and spectral ranges. It is believed that the ripple effect presents the obvious incomplete interference, and its period and amplitude are mainly determined by the structure of V-shaped cavity and its surface pollution status of folded-mirror, respectively, have little relation with the spectral scanning region. All these show that the spectral ripple is mainly from the part interference effect of light on folded-mirror.