Enhanced background rejection in thick tissue using focal modulation microscopy with quadrant apertures

▶ Focal modulation microscopy using quadrant apertures (QFMM) can simultaneously provide better axial resolution and transverse resolution than normal confocal microscopy. ▶ The spatial resolution in QFMM is identical in both horizontal direction and vertical direction. ▶ The investigation of the background rejection capability demonstrates that QFMM can enhance the background rejection, thus increasing the imaging penetration depth. ▶ QFMM can effectively improve the signal level, implying that QFMM can reduce photon-damaging and photon-bleaching in biological science and medical diagnosis.