Very long lasers.

The properties and oscillation characteristics of very long cw xenon lasers are discussed and pertinent long laser experiments described. High-gain 3.508-microm xenon laser amplifiers were used in these experiments. Laser cavity lengths of up to 30 km were studied. Spectrum analyses revealed complex oscillation spectra exhibiting the characteristics of both homogeneous and inhomogeneous laser mode structures. Long laser Doppler experiments, Q-switching studies, and modulation experiments were performed. Applications to atmospheric pollution detection are discussed.