Figure 6

Power coupling efficiency using two spherical mirrors versus the ratio d1/zo for d2=R/2 in (a) and versus d2/zo for d1=R/2 in (b), at different zo/R ratios.
Power coupling efficiency using two spherical mirrors versus the ratio d1/zo for d2=R/2 in (a) and versus d2/zo for d1=R/2 in (b), at different zo/R ratios.