3. Continuous wave dye lasers II

Abstract

In the foregoing chapter by Snavely on continuous-wave dye lasers, early results on cw dye lasers are discussed. Besides theoretical descriptions of dye properties and gain analysis, results on tuning of cw dye lasers are given. In this chapter the latest achievements in modern cw dye laser design will be described. In Sect. 3.1, cw dye lasers in linear configuration are discussed. Special emphasis is devoted to the free running jet technology and to tuning elements, e.g. birefringent filters. Section 3.2 treats single mode (SM) operation of linear laser systems. The most recent results on traveling-wave (TW) operation of ring dye lasers are described in Sect. 3.3. Special attention is given to SM operation and to some ring laser devices, e.g. undirectional devices. The chapter concludes with a short discussion of frequency doubling in cw dye lasers. Frequency stabilization techniques are not discussed, since the description of these techniques exceeds the scope of this book. As discussed in Chap. 2, the threshold excitation power density of a practical cw dye laser system is about 50 kW/cm 2. This high power density is not easily obtained by arc discharge lamps. Therefore it was a widely held notion that cw dye lasers cannot be pumped with incoherent light sources. Thiel et al. (1987) have reported cw operation of a dye laser, pumped by a high pressure arc. With an electrical input power of 8.8 kW they were able to reach threshold. However, it remains to be seen whether the output power of an incoherently pumped dye laser can be raised into the milliwatt range.