Large hollow-core fiber random dye laser

Random lasers (RL) have several interesting features that cannot be achieved with common bulk or fiber lasers such as simultaneous emission of several different wavelengths at the same time and emission at new extremely low gain lines. They also permit miniaturization and very low cost. To make the random emission useful, some sort of guiding mechanism that collects the stimulated emission is desirable. In this work we propose the use of a hollow-core photonic crystal fiber (HC-PCF) based on a large-pitch Kagome lattice to achieve a quasi-one-dimensional random laser (1D-RL) emission. The effective guiding property is demonstrated by a lower threshold of the high-gain scattering media RL inside the HC-PCF when compared with bulk RL emission inside a fluorescence cell. During the experiment, a strong and well collimated yellow emission, around 570 nm, was observed. We can also observe a strong reduction in linewidth for the pure dye solution suggesting ASE (amplified spontaneous emission). Thus, the use of the Kagome fiber permits a quasi 1D-RL that could be used in diverse applications.