Better than a lens? Increasing the signal-to-noise ratio through pupil splitting

Incoherent imaging via an unmodified full pupil seemingly yields the maximum achievable signal-to-noise ratio (SNR) with respect to a fixed photon budget. Such photon-limited SNR is critical in many scenarios, for example, case of fluorescence microscopy. In this work, we propose general method that achieves better transmitting high spatial frequency information through optical system, without need capture more photons. This achieved by splitting incoherent system such two sub-images are simultaneously acquired and computationally recombined. We compared theoretical performance split non-split scenario implement using tilted elliptical mirror covering ≈50% pupil, placed at back-focal-plane (BFP) widefield microscope. Additionally, proposed exhibits extended-depth-of-field (EDoF), utilized further assign some measured (in-focus) signal different axial planes reconstructed sample, thick slice deconvolution. Our can be modified tailor enhancements specific metrology tasks or exploit other properties (e.g., spectral polarization information) enhancement impact on future schemes.