Ge Infrastructure Sensing, Inc.

Daniel M Stearns

Hejie Li

Anthony Kowal

Yufeng Huang

John McKinley Poole

Shawn David Wehe

Xiaoyong Liu

Gene Smith Berkowitz

In one embodiment of the spectroscopy method, the method comprises the steps of modulating the wavelength of a monochromatic radiation at a modulation amplitude and a modulation frequency; determining a first variable representative of an absorbance of an analyte in a sample; and demodulating by phase-sensitive detection the first variable at a harmonic of the modulation frequency to produce a harmonic spectrum of the analyte. In one embodiment of the spectroscopy apparatus, the apparatus comprises a laser diode integrated with a first photodetector configured to detect an intensity of a backward emission from the laser diode and act as a reference detector; a second photodetector configured to detect an intensity of laser radiation exiting a sample; and electronic circuitry coupled to the laser diode and the photodetectors, configured to acquire and process spectra of the sample. In another embodiment, the spectroscopy apparatus comprises a beam splitter configured to split the laser radiation into a first radiation portion and a second radiation portion and a first photodetector configured to detect the intensity of the first radiation portion.

Wavelength-modulation spectroscopy method and apparatus

Growing community of inventors

Canton, MA, United States of America

Daniel M Stearns