10] The use of lasers for one- and two-photon photolysis of caged compounds

Abstract

This chapter gives basic knowledge of laser systems to use them reliably and safely in experiments involving photolysis of caged compounds. The basic concept involved in lasers is that of stimulated emission; in fact, the acronym laser means “light amplification by stimulated emission of radiation.” While using lasers, it is very important to realize that one is dealing with high-intensity light so that normal light filters used in the biochemical laboratory should not be used to protect the eyes from laser light. The stimulated emission must also be taken into account when high-intensity (laser) light is being used. For low-intensity light, only absorption and fluorescence need to be taken into account. The chapter provides some important safety points. The voltages used in pulsed laser systems come from high-voltage power supplies. Users are well protected from these voltages, but if one takes off the protective covers, extreme care must be exercised in order to avoid electrocution. Also, all laser beams should be covered, and any unused reflections or final main beams should be dumped in recessed blackened beam stops.