Figure 6(b) shows the laser beam spot captured on the CCD camera with the lens. The image has been transformed into gray scale before intensity analysis with MATLAB® (Mathworks). The beam intensity profiles along the vertical and horizontal directions are also shown. The images were captured at 5.4, 5.6, and 5.8 mm distances. The focal length is found to be 5.6 mm, where the full-width half-maximum of the point spread function is captured as the minimum with the CCD camera. Figure 6(c) shows the comparison of the focal length of lenses created with various droplet volumes at 200°C. The focal lengths for volumes of 10, 25, 50, 75, 100, 125, 150, 175, and were , , , , , , , , and , respectively.