Abstract: A method and system for improving lateral resolution in optical microscopy are provided. The method includes generating a source optical beam and passing the source optical beam successively through an axicon, a Fourier-transform lens and an objective to convert the source optical beam into an excitation Bessel-type beam having a central lobe and at least one side lobe. The method also includes focusing the excitation beam onto a focal plane of the objective within or on a sample to generate a sample light signal, and spatially filtering the sample light signal. The spatial filtering includes rejecting light originating from outside of the focal plane and light generated by the at least one side lobe of the excitation beam. The spatial filtering also includes permitting passage, as a filtered light signal, of light generated by the central lobe of the excitation beam. The method further includes detecting the filtered light signal.