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 surgical applications in medicine. Since I
first entered the laboratory of Professor Yasuharu Suematsu in 1962 to
complete my thesis, I have been studying the new field of laser optics.
In spite of many expectations and a vast investment in research, the
first practical use of lasers was difficult to of Univ. Erlangen once
jokingly achieve. The late Professor K. H. Zchauer remarked that laser
was defined by an English physicist as "Less Application of Stimulated
Expensive Research. " In a similiar vein, Dr. Herwig Kogelnik reminded
me that in the early 1960s, maser was often called "Money Acqui- sition
Scheme for Expensive Research. " Initially I worked with a ruby laser,
then with a helium-neon-gas laser, and am presently engaged in
semiconductor laser research. There are proba- bly not a large number of
researchers who have had the opportunity to build these three
representative types of lasers. My primary objective of study lies in
optical communications however, and therefore, I have been approaching
the laser mainly as a lightwave propagator.