Multiple-prism grating laser oscillator

Multiple-prism grating laser oscillators,[1] or MPG laser oscillators, use multiple-prism beam expansion to illuminate a diffraction grating mounted either in Littrow configuration or grazing-incidence configuration.

Originally, these narrow-linewidth tunable dispersive oscillators were introduced as multiple-prism Littrow (MPL) grating oscillators,[2] or hybrid multiple-prism near-grazing-incidence (HMPGI) grating cavities,[3][4] in organic dye lasers.

[11] Under those conditions, that is, zero dispersion from the multiple-prism beam expander, the single-pass laser linewidth is given by[1][11] where

In the case of multiple-prism beam expanders this factor can be as high as 100–200.

[1][11] Optimized solid-state multiple-prism grating laser oscillators have been shown, by Duarte, to generate pulsed single-longitudinal-mode emission limited only by Heisenberg's uncertainty principle.