Investigation of fields in wide-aperture plane resonators

Theoretical and experimental investigations were carried out (in the latter case using a neodymium glass laser) of methods for separating the individual monochromatic self-imaging (self-reproducing) fields in a wideaperture resonator by inserting amplitude gratings and grating mirrors. It is shown that the use of these in a plane resonator provides an effective means for increasing the spatial coherence and for stably exciting monochromatic fields having various spatial characteristics. It is pointed out that gratings can be used to control the lasing frequency, and to produce phase modulation and convert the fields into each other on introducing an additional phase grating into the resonator.