It is surprising how easy it is to damage a lens or other optical component with a laser. A typical occurrence is during the alignment of lab optics, where the slightest tweak results in the sound of a cracked coating, broken glass, or worse. This is not due to any inherent weakness of laser system optics, but of the tight focus to which coherent beams can be imaged, resulting in unintended consequences when re-imaged back-reflections are focused to a high power density.
Laser system optics are also susceptible to—and will contribute to - system wavefront error. As we have seen in Chapter 3, one source of WFE in a laser system is the laser modes themselves, for which the beam-quality factor M2 is used to estimate the focused spot size and far-field divergence angle. In this chapter, we will see that there are other sources as well: thermal lensing, optical fabrication WFE, aberration WFE, and so on.
Online access to SPIE eBooks is limited to subscribing institutions.