Fig. 3.

(a) PA image stack of the blood vessels in a mouse ear acquired by high-energy wavelength scanning, low-energy wavelength scanning, and spectrally encoded PA microscopy. (b) DMD-encoding masks, corresponding illumination spectra and PA image stack of the blood vessels in a mouse ear acquired by spectrally encoded PA microscopy. (c) Blood absorption spectra in the thin vessel (artery). (d) Blood absorption spectra in the thin vessel (vein). (e) Comparison of ${\mathrm{SO}}_2$ images acquired by high-energy wavelength scanning, low-energy wavelength scanning, and spectrally encoded PA microscopy.