Temporal dynamics of diode-pumped circulation-free liquid dye lasers

Abstract

A highly stable diode-pumped circulation-free liquid dye laser in a vertical external cavity is reported. The design is simple (no fabrication process step required, no fluid circuitry), compact (~ cm sized), and cost-effective. An optical efficiency of 18% with a M${}^2$ of 1 are reported, with an excellent photostability-no efficiency drop was seen after 1.4 million pulses at 50 Hz, a value comparable to flowing systems and much higher than values achievable with organic solid-state lasers. We show that thermal effects are central in the stability and also on the dynamics of this laser. The laser build-up and shutdown dynamics are studied in detail for different pump pulse durations/repetition rates; they reveal a pulse shortening with increasing pump pulse duration and repetition rate that are shown to be due to thermal lensing diffraction losses. This laser structure offers a very convenient and simple platform for testing or harvesting solution-processable gain materials.