6 - Transition Metal Solid-State Lasers

Abstract

This chapter discusses various aspects of transition metal solid-state lasers. Transition metal lasers have active atoms that come from the fourth row in the periodic table of the elements, whereas lanthanide series lasers have active atoms that come from the sixth row. Transition metal lasers are usually tunable over a relatively wide spectral range, whereas the tuning range of lanthanide series lasers is relatively limited. In transition metal lasers, electrons in the 3d subshell participate in the lasing process. Transition metal atoms that demonstrate laser action reside in the fourth row of the periodic table of the elements. Crystal-field effects contribute strongly to the energy levels of the 3d electrons of a transition metal atom embedded in a laser material. Absorption and emission of transition metals in a laser material are characterized primarily by band structures. The absorption and emission spectra are characterized by broad spectral features. It is the broad absorption features that allow transition metal atoms to be efficient absorbers of the broadband flashlamp radiation. It is found that slope efficiencies of a Cr:BeAl2O4 laser can be relatively high, primarily because of the efficient absorption of the flashlamp radiation.