Fig. 1. TPF microscopic imaging as well as TPF spectroscopy system. BS: beam splitter; L3, L4, SL, TL: lens; GM: scanning oscillator; OBJ: objective; M: reflector; F: filter; PMT: photomultiplier tube; PC: computer

Fig. 2. (a) Spectra of femtosecond laser; (b) Fluorescence spectra of rhodamine B

Fig. 3. (a) Imaging area of mouse brain (in dashed box); (b) TPF microscopic image of a mouse brain slice

Fig. 4. (a) TPF imaging plot of mouse brain at 100 mW excitation power; (b) The trend of average fluorescence intensity with power squared for the regions of A, B, C (inside the blue box)

Fig. 5. (a) Tomography imaging of mouse brain; (b) Imaging results of mouse brain slice along the Y-axis

Fig. 6. (a)-(f) TPF microscopy results of mouse brain at 0 μm, 2 μm, 4 μm, 6 μm, 8 μm, and 10 μm

Fig. 7. (a) Intensity distribution curves of mouse brain gray matter at different depths; (b) Intensity distribution curves of mouse brain white matter at different depths

Fig. 8. Average fluorescence intensity changing curves with depth in gray and white matter tissue of mouse brain

Fig. 9. Four consecutive 100 pixels with gaps of the mouse brain samples

Fig. 10. Intensity distribution curves of four lines in mouse brain imaging