Patent ID: 7106763
Filing Date: 2006-09-12
Classification: G01N

Abstract:
1. A cavity ring-down spectrometer comprising: i) a resonant optical cavity comprising at least two high reflectivity mirrors; ii) a source for providing a continuous wave optical signal into said optical cavity, said source comprising an electrically pumped semiconductor gain medium; iii) a first detector for monitoring the intensity of radiation emitted from said cavity and generating a first detection signal based thereon; iv) a first controller for deactivating said optical signal based on a comparison of said first detection signal and a predetermined threshold and for thereafter reactivating said optical signal after a delay period in excess of the ring-down time for said optical cavity; v) a second detector for monitoring the wavelength of the reactivated optical signal and generating a second detection signal based thereon; vi) a second controller coupled to said second detector which second controller adjusts both the temperature of, and the current to, said gain medium to thereby achieve a desired emission wavelength; vii) means for adjusting the beam path length of the optical cavity to be in resonance with said desired emission wavelength.