SIMULTANEOUS RANGING AND REMOTE CHEMICAL SENSING UTILIZING OPTICAL DISPERSION OR ABSORPTION SPECTROSCOPY

摘要

A system for simultaneous optical pathlength determination and remote chemical sensing of a sample disposed along an optical path. A modulated laser source configured for modulated light emission so that at least one spectral sideband with a sideband frequency is created, the modulated light emission is directed along the optical path and sideband frequency is varied over time. A detector is configured to detect transmitted light along the optical path and generate a detected light intensity signal. A frequency down-converter is configured to receive the detected light emission signal and generate a frequency down-converted light intensity signal. A demodulator is configured to demodulate the frequency of the down-converted light intensity signal and output an instantaneous frequency. A pathlength calculator is configured to determine an optical pathlength to the sample based on the instantaneous frequency. A frequency down-converted light intensity signal is simultaneously output for spectroscopic chemical sensing.

主权项

1. A system for simultaneous optical pathlength determination and remote chemical sensing of a sample disposed along an optical path, the system comprising:
a modulated laser source configured for modulated light emission so that at least one spectral sideband with a sideband frequency is created, the modulated laser source being configured to direct the modulated light emission along the optical path, the modulated laser source being configured to vary the sideband frequency over time; a detector configured to detect transmitted light from the optical path and generate a detected light intensity signal; a frequency down-converter configured to receive the detected light emission signal and generate a frequency down-converted light intensity signal; a demodulator configured to demodulate the frequency of the down-converted light intensity signal and output an instantaneous frequency; a pathlength calculator configured to determine an optical pathlength to the sample based on the instantaneous frequency; and the frequency down-converted light intensity signal being simultaneously output for spectroscopic chemical sensing.