Fig. 4.

(a) Measured light intensities at the two wavelengths (785 and 853 nm) collected by the single-mode (SM600), few-mode (SM980), and multimode (1 mm) fibers during the phantom titration experiment. The light intensity unit of “kcps” stands for kilo counts per second; (b) averaged light intensities and standard deviations of noise (error bars) at the two wavelengths. The standard deviations of noise are multiplied by a factor of 100 to clearly display the error bars; and (c) corresponding SNRs of light intensities at the two wavelengths and five titration steps.