Subaperture sampling for digital-holography applications involving atmospheric turbulence

Using wave-optics simulations, this paper defines what subaperture sampling effectively means for digital-holography applications involving atmospheric turbulence. Throughout, we consider the on-axis phase shifting recording geometry (PSRG) and off-axis PSRG, both with the effects of sensor noise. The results ultimately show that (1) insufficient subaperture sampling manifests as an efficiency loss that limits the achievable signal-to-noise ratio and field-estimated Strehl ratio; (2) digital-holography applications involving atmospheric turbulence require at least three focal-plane array (FPA) pixels per Fried coherence length to meet the Maréchal criterion; and (3) off-axis PSRG is a valid and efficient implementation with minor losses, as compared to on-axis PSRG. Such results will inform future research efforts on how to efficiently use the available FPA pixels.