Fig. 1. Absorption (a) and emission (b) spectra of PbS quantum dots in different sizes

Fig. 1. [in Chinese]

Fig. 2. Composition of the fluorescence detection system for infrared quantum dot

Fig. 3. PL spectrum of the infrared quantum dot material sample

Fig. 4. Signal processing flow chart of the fluorescence detection system

Fig. 5. Laser echo signal waveforms for infrared quantum dot samples at different modulation frequencies

Fig. 6. Output waveforms of the amplification circuits without (a) and with (b) untested quantum dot samples

Fig. 7. Variation of output DC voltage of the detection system for quantum dot fluorescence

Fig. 8. Fluorescence detection signal waveforms of sample B （before and after phase sensitive detection）

Fig. 9. The maximum detectable distance of fluorescence for quantum dot sample varies with the power density of excitation light