(LIGHTTRANSPinhole Modeling in a Low-Fresnel-Number SystemAbstractModeling of imaging systems with lowFresnel numbers is known to bechallenging.In such systems,the lightpropagation is greatly determined bydiffraction,and,to correctly model thecomplete system,possible diffractions atmultiple surfaces and apertures must beconsidered.With the Fourier transformsettings in VirtualLab Fusion,theinclusion of such diffraction effects can beadjusted flexibly.In this example,weshow effect of the diffraction due to lensapertures and pinhole inside a low-Fresnel-number system.2Modeling TaskIn the low Fresnel-number system,we showhow does the pinhole truncate the light at theintermediate image plane,andhow to calculate the spot size at the final image planelens #2pinholeintermediatelens #1D=0.8mmimage planecircularD=0.4mmD=0.2mmimageinput plane waveplanewavelength 500nmon-axis and fullillumination of lens #1assumed from infinity250mm250mm50mmsystem parameters adapted from Fig.9,M.Mout,et al.,Appl.Opt.55,3847-3853(2016)3