Modulation frequency multiplexing provides a straightforward method, analogous to television or radio broadcasting, for performing simultaneous detection of multiple gases by use of wavelength modulation spectroscopy with diode lasers. When fiber-optic coupled lasers are used, our approach guarantees that all beams transit the same optical path and impinge on the same detector. Each laser is modulated at a different frequency and the detector output is processed by a set of lock-in amplifiers, one for each laser, to measure the absorbance encountered by each laser.
No takes yet. Share an insight, caveat, or question.
Oh et al. (1998) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: