By the recent development of super-resolution techniques, the spatial resolution of optical microscopy is no longer limited by the wave nature of light. e common concept that has enabled us to break the diraction limit is utilizing the switching, blinking, or nonlinear property of uorescence emission of probes that label a sample. Localization microscopy, such as photoactivated localization microscopy (PALM) or stochastic optical reconstruction microscopy (STORM), relies on the photoactivation, photoconversion, and transition to dark state of uorescent probes to separately image the emitters in a sample (Hofmann et al. 2005, Betzig et al. 2006, Hess et al. 2006, Rust et al. 2006, Fölling et al. 2008). Stimulated emission depletion (STED) microscopy utilizes the saturation eect in stimulated emission to make the size of the donut hole small far beyond the diraction limit (Hell and Wichmann 1994, Klar and Hell 1999).