We present a novel technique for considerably decreasing the sidelobe height of the axial point-spread function of one-photon 4Pi-confocal microscopes. By means of a numerical example, in which the ratio between the excitation and the fluorescence wavelengths was set to ε=λ<sub>exc</sub>/λ<sub>det</sub>=0.8, we show that simply inserting a pair of properly designed two-ring binary masks in the illumination set allows the height of the axial sidelobes to be reduced from 20% to 5% of the height of the central peak. This allows one to receive the full benefit of the strong narrowness of the central lobe provided by the 4Pi-confocal technique.
© 2002 Optical Society of America
Manuel Martínez-Corral, Amparo Pons, and María-Teresa Caballero, "Axial apodization in 4Pi-confocal microscopy by annular binary filters," J. Opt. Soc. Am. A 19, 1532-1536 (2002)