Single-mode operation of a zigzag dye laser

We report single-mode operation of a laser pumped zigzag dye laser for pulse lengths >1 /spl mu/s with beam quality close to the diffraction limit. A unique linear optical cavity using counter-propagating orthogonally polarized waves was used. Laser efficiency measurements performed with a stable cavity had outputs of greater than 1.7 J at 568 mn using Pyrromethene-567 dye. The intrinsic laser efficiency was 55% with a slope efficiency of 77%. Single-mode operation was achieved using an unstable resonator with intra-cavity etalons to control the free running modes of the cavity and seeding with a single-mode Kr-ion laser operating at 568 nm. Heterodyne measurements were used to determine that the bandwidth was near the transform limit with the frequency chirping at a rate /spl sim/60 MHz/Ms. Far-field measurements of the beam quality indicated close to diffraction limited output.<
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