Figure 8
Quantification of resolution provided by a ball lens with \(R=1\) mm at \(\lambda \)=480 nm. (a) Image of the Siemens star showing the cross-sections (dashed lines) along which the intensity profiles were measured. (b) Experimental intensity profiles (points) and estimated maximum and minimum of intensity levels (horizontal solid lines). The x scale is obtained after dividing the image coordinates by magnification. (c) Theoretical variation \(f(W/L)=(I_{\rm peak}-I_{\rm dip})/I_0\) for a periodic stripe pattern for several values of \(L_1/L\). (d) Experimental points fitted with the theoretical f(W/L) at \(L_1/L=0.6\) for several sets of FWHM W and intensity \(I_0\). The solid red line shows the best fit while the two dashed lines show much worse fits for slightly different parameter sets.
