Delayed self-heterodyne interferometer measurements of narrow linewidth fiber lasers

Summary form only given. Narrow linewidth lasers are critical for many scientific applications, including sensing, coherent signal generation, the study of quantum phenomena, and phase-sensitive systems. One key practical technology for generating narrow linewidths is the fiber ring laser. The delayed self-heterodyne interferometer (DSHI), in which one arm is delayed to decorrelate the phases of the optical fields before recombination, is commonly used for laser linewidth measurements.