Transverse mode beating in high-Q pulsed dye lasers

This work provides a detailed analysis of transverse mode beating in high-Q pulsed dye lasers, achieved without the use of intra-cavity tuning elements, pinhole apertures, or external modulators. Various resonator configurations were tested, and the effects of the pump beam size on the laser emission were explored. Depending on the resonator configuration and pumping conditions, the emission could be single mode, with no beating, exhibit beating of a few transverse modes, or become multimodal with lost coherence. The simultaneous acquisition of the spatial, spectral, and temporal profiles of each output laser pulse reveals that mode beating is established from the onset of laser operation.