Fig. 2.

Variations in FWHM of ${\text{PSF}}_{\text{tot}}^{\text{MMM}}$ as a function of imaging depth due to photon scattering. FWHMs in (a) transverse direction and (b) axial direction were measured from surface down to the imaging depth of $2\times l_{\text{s}}^{\text{em}}(l_{\text{s}}^{\text{em}}=62.5\mu m)$ at emission wavelength (515 nm). There was no significant change of ${\text{PSF}}_{\text{tot}}^{\text{MMM}}$ FWHM in either direction.