Laser Electronics (3rd Edition)

Book Preface

The underlying philosophy of this third edition of Laser Electronics is the same as in the previous two: lasers are very simple devices and are far simpler than the very complicated high frequency RF or microwave transistor circuits. The main purpose of the book is to convince the student of this fact. In one sense, lasers are a simple movement of the decimal point on the frequency scale three to five places to the right, but much of the terminology and all of the insight developed by the earlier pioneers of radio have been translated to the optical domain.

The potential of the many applications oflasers and optical phenomena has necessitated the formation of a new word to describe the field: photonics. One would be hard pressed to define all of its ramifications since new ideas, devices, and applications are frequently being added. In a very loose sort of way, the early history of radio is being repeated in the optical frequency domain, and this is a theme that will be employed throughout the book.

Although both have a common basis in electromagnetic theory, there are special phenomena peculiar to the optical wavelengths.

For instance, a wave intensity of 1015_1019 watts/m2 would have been incomprehensible in 1960, but is now attainable with rather common lasers and comparativel y cheap optics. Similarly, a 50 femtoseconds (50 x 10-15 s) pulse requires more frequency bandwidth for transmission than that which was installed in all of the telecommunications networks of 1960. Yet such a pulse is rather common with optical techniques.