the minimum spot size achievable accompanied with an enhanced Strehl ratio as we drop the most intensity inefficient mode. Overall, the Strehl ratios determined in our studies predominantly exceeded values of $1\%$ even when spots were tightly squeezed. Therefore, the observed decrease of intensity is not to severe in terms of potential applications of squeezed beams such as optical manipulation and imaging.

![(a) Transversal and (b) longitudinal 2D intensity cross sections of the OEi superposition delivering the smallest focal spot in the ROI ($R=\lambda$) considering 25 LG modes. $w/w_0$ is the relative spot size measured according to Eq. . The Strehl ratio in (a) is $4.5\%$.[]{data-label="fig3"}](MaziluFig3.pdf){width="12cm"}

![(a) Spot size as a function of the radius of the ROI for different number of LG modes considered. The right hand scale and filled curve indicate the numbers of intensity eigenmodes $N^{(0)}$ fulfilling the intensity criteria for the $N=11$ case. The arrows indicate the corresponding scales. (b) Ratio between the ROI intensity of the smallest spot size eigenmode and the largest intensity achievable in the ROI (Strehl ratio).[]{data-label="fig4"}](MaziluFig4.pdf){width="13cm"}

![(a) Radial wavevector spectral density. Yellow highlights regions outside the spectral bandwidth. (b) Transversal cross section of the OEi spot size optimized field intensity with 