The radial structure of the transversal modes causes a corresponding structure of the gain coefficient g(r). This gain reacts on the modes and distorts the field distribution. In such small gain laser systems as He-Ne, the distortion is small and the transversal modes differ little from those of the empty resonator. But in high-power, solid-state, or CO2 lasers the situation is different.
© 1984 Optical Society of AmericaPDF Article