The effect of geometry arrangements of optical-limiting media with cubic nonlinearities in infrared focused optical-detecting systems on the optical limiting was calculated and analyzed by using beam propagaton and Gaussian decomposition (GD) methods, and optimum geometry arrangements were given in the analysis. The results show that the optical limiting for the near-field geometry arrangement is very different from that for the far-field geometry arrangements, and in some geometry arrangements nonlinear media with positive nonlinear index can not be employed as optical-limiting media, which is different from previous suggestions for the far-field geometry arrangements. It is also shown that focused geometry arrangements can be employed for measurements of nonlinear refractive index with a higher sensitivity than that of common Z-scan techniques.