Elliptical mirror based imaging with aperture angle greater than π/2

Elliptical mirror based imaging systems permit aperture angles greater than π/2 to be realized. It is therefore possible to collect part or all of both the forward and backward diffractive fields emitted from single molecules. In this paper we derive rigorous formulae for the image intensity when the single molecule is modeled as a dipole emitter. It is found in theory that the point spread function can be 2.44 times narrower at fullwidth- half-maximum in the axial direction when using an elliptical mirror with the maximum aperture angle of 2π/3 as compared with a parabolic mirror system with the aperture angle of π/2 whereas the side lobe level is increased by only 0.21% when the dipole is oriented along Z axis.