Patent ID: 9097583
Filing Date: 2015-08-04
Classification: G01J,G01N

Abstract:
1. A mid-infrared spectrometer, comprising: a wavelength-tunable pulsed-mode infrared laser; an optical cavity having a finesse defined by at least 0.999 reflectivity mirrors, the cavity bounds a sample cell with an inlet and outlet for receiving a gas sample therein, with wavelength-scanned infrared pulses from the laser being coupled into the optical cavity, the pulses having an effective optical path length in the cavity of at least 1 km; a detector positioned to receive and detect infrared light exiting the cavity so as to supply a cavity ring-down trace representative of sample absorption by the infrared pulses; and a processor coupled to receive the ring-down trace from the detector, the processor configured to determine an absolute absorption spectrum of the gas sample and analyze sample gas composition and trace concentration from that spectrum.