Simultaneous defocusing of the aperture and medium on a spectroholographic storage system

In a spectroholographic storage system the defocusing method is often used to obtain spectrum uniformity and improve the quality of the recorded information. However, defocusing introduces vignette and stronger interpixel cross talk in the marginal field of view. We report a method that defocuses the aperture and medium together. Based on the pixel spread function, two inequalities are introduced to estimate the upper and lower bounds of the energy received at the CCD. We balance the spectrum uniformity with interpixel cross talk and vignette and then allow the designer to select optimal structure values of the defocusing spectroholographic storage system, i.e., the defocusing value, aperture size, and fill factors for the spatial light modulator and CCD.