The laser, initially called the "optical maser," was proposed in 1958 by Charles Townes and Arthur Schawlow; in 1960, Theodore Maiman was the first among several researchers to achieve laser oscillation by using a ruby crystal. In the following quarter of a century, a considerable amount of re- search and development has taken place, and the laser is now utilized for many diverse applications, ranging from the commonplace compact disk to intricate...