HELICAL-WAVE EMISSION OF LASERS

The emission of higher-order helical waves from lasers is experimental ly investigated. Multistability between different helical states and t ime-dependent emission occurs for class B lasers. The statistical appe arance of the different states can be influenced by radial and azimuth al variation of the losses in the laser resonator. Second-order helica l-wave emission is also demonstrated for a class A laser. In the case of a small astigmatism the spatial intensity distribution is linked to the helicity.