Just adding on to taniwha's correct comments -- it is possible to indirectly image the charge using thermal stimulation of the laser to induce the Seeback effec

Just adding on to taniwha's correct comments -- it is possible to indirectly image the charge using thermal stimulation of the laser to induce the Seeback effect. The local heating will cause the current consumption of the chip to shift ever so slightly in a fashion that's dependent on the state of the transistor's bias. [1] is where I first read about the technique. [1] https://eprint.iacr.org/2018/717.pdf https://eprint.iacr.org/2018/717.pdf