This is the second edition of the book entitled Ocular Photocoagulation: A Stereoscopic Atlas (1975) by a person who has been active in the development and uses of lasers. Since that time, several new lasers have become available that emit different wavelengths, levels of absorption, and action on tissues.
A chapter by Arthur Vassiliadis, PhD, describes the physical basis of the various lasers. Briefly, light stimulation of low energy atoms of a crystal, gas, or dye excites the atoms with increase in the energy level and temperature. The laser material is in an optical cavity between two resonance mirrors that result in "light amplication" with "stimulated emission" through one partially transparent mirror of "radiation" photons with coherent monochromatic wavelength that depends on the laser material. Hence, the name LASER.
The characteristics of each laser are described in detail, including mechanical features, power, wavelength, and level of absorption in each tissue.