(A) Main parts of the TPLSM . 2-photon excitation can have advantages for 3D imaging of the relatively thick, up to 1 mm and more objects in vitro as well as in vivo. (B) Three-dimensional TPLSM high-resolution image . (C) Intravascular oxygen could be measured over various depths of cortex by TPLSM. The color bar shows the calculated partial pressure of oxygen at the measured location .