Long coherence length for cw photolytic atomic iodine lasers at 1.315 microm

With a low-power cw photolytic atomic iodine laser operating at 1.315 microm, coherence lengths greater than 220 m have been observed. These results are to our knowledge the first coherent length measurements of any type of atomic iodine laser. A Michelson interferometer was used to demonstrate this long-coherence-length property. In addition, Fabry-Perot interferometric measurements provided a laser frequency linewidth (Deltaf < 1.0 MHz) consistent with this long-coherence-length observation. Such a large coherence length should be common to all homogeneously broadened, photolytic atomic iodine lasers.