Copyright 1996 Gordon Publications. Used by permission. The highly collimated laser beam delivers this energy in a precise position, size, distribution, and at very high intensity levels. The capability to accurately define the intensity distribution, or beam profile, and the laser mode content is a critical attribute of most laser applications. Deterioration Of Laser Beam Profiles Deterioration of the beam profile is the major cause of reduced laser performance.
Many factors can cause or contribute to beam profile and mode content instabilities.
When a change occurs in the intensity profile, even if the total power or energy in the beam remains unchanged, performance can be seriously compromised. Some of these sources of instability can cause the beam to change to multimode operation, while others can introduce scattering of light and non-uniform intensities. In the face of these potential problems, the availability of high-quality instrumentation for tracking the intensity distribution becomes a definite asset to optimum laser performance. LiSAF amplifier stage, the near-Gaussian beam of Figure 1 has been transformed into a more ragged beam, with about 15 percent of its energy in the wings. Figures 1 and 2 show a common problem in high-energy research lasers.