Fig. 1. Schematic diagram of experimental setup for FOFL biochemical sensor

Fig. 2. Monitoring results of RBH ring-opening reaction process. (a) Output spectra at different reaction times; (b) variation of spectrally integrated intensity with reaction time, insets show enlarged view of data points in 215-240 min range and enlarged view of spectra of laser peak at 230 min, respectively

Fig. 3. Experimental results of RBH concentration measurement. (a) Output spectra with no Hb present in reaction solution; (b) output spectra in presence of Hb in reaction solution; (c) relationship between RBH concentration and spectrally integrated intensity

Fig. 4. Experimental results of Cu²⁺ concentration measurement. (a) Output spectra with no Hb present in reaction solution; (b) output spectra in presence of Hb in reaction solution; (c) relationship between Cu²⁺ concentration and spectrally integrated intensity

Fig. 5. Relationship between pump energy and spectrally integrated intensity, inset shows spectra at pump energies of 5, 12, 19 µJ

Fig. 6. Experimental results of Hb concentration measurement. (a) Laser spectra at different Hb concentrations; (b) relationship between spectrally integrated intensity difference and Hb concentration