Fig. 3: Spatial resolution of QMC.
a Simple schematic of QMC. BBO, β-barium borate crystal. EMCCD, electron multiplying charge-coupled device camera. \({{{{{{\bf{r}}}}}}}_{0}\), \({{{{{{\bf{r}}}}}}}_{1}\), and \({{{{{{\bf{r}}}}}}}_{2}\) are the coordinates of the source Fourier plane, the object plane, and the detection plane, respectively. \({{{{{{\bf{r}}}}}}}_{0,s}\), \({{{{{{\bf{r}}}}}}}_{1,s}\), and \({{{{{{\bf{r}}}}}}}_{2,s}\) are the corresponding coordinates in the signal arm, and \({{{{{{\bf{r}}}}}}}_{0,i}\), \({{{{{{\bf{r}}}}}}}_{1,i}\), and \({{{{{{\bf{r}}}}}}}_{2,i}\) are the coordinates in the idler arm. \(h\left({{{{{{\bf{r}}}}}}}_{0,s},{{{{{{\bf{r}}}}}}}_{1,s}\right)\) and \(h\left({{{{{{\bf{r}}}}}}}_{1,s},{{{{{{\bf{r}}}}}}}_{2,s}\right)\) are the PSFs from \({{{{{{\bf{r}}}}}}}_{0,s}\) to \({{{{{{\bf{r}}}}}}}_{1,s}\) and from \({{{{{{\bf{r}}}}}}}_{1,s}\) to \({{{{{{\bf{r}}}}}}}_{2,s}\). \(h\left({{{{{{\bf{r}}}}}}}_{0,i},{{{{{{\bf{r}}}}}}}_{1,i}\right)\) and \(h\left({{{{{{\bf{r}}}}}}}_{1,i},{{{{{{\bf{r}}}}}}}_{2,i}\right)\) are the PSFs from \({{{{{{\bf{r}}}}}}}_{0,i}\) to \({{{{{{\bf{r}}}}}}}_{1,i}\) and from \({{{{{{\bf{r}}}}}}}_{1,i}\) to \({{{{{{\bf{r}}}}}}}_{2,i}\). \(t\) is the amplitude transmission coefficient of the object. Classical (b) and QMC (c) images of group 7 (2.76 ~ 3.91 μm) of a USAF 1951 resolution target. Scale bars, 20 μm. All the images are normalized by their maximum and minimum intensities (see “Methods”). d Spatial resolution of classical imaging and QMC versus the axial z coordinate from the classical focal point. The highest spatial resolutions for classical imaging and QMC are 2.9 μm and 1.4 μm, respectively. Data are plotted as means ± standard errors of the means (\(n=14\)). e Normalized lateral LSFs of classical imaging and QMC versus the lateral coordinate at different z positions.
