Abstract

Fiber lasers, in which the active medium is a dopant in an optical-fiber core, are attractive because of their potential for narrow-linewidth operation. A number of fiber-laser configurations, yielding a single-mode regime, have been investigated.^1–3 These lasers achieve single-frequency operation by using frequency-selective elements in the cavity, including an optical isolator to secure traveling-wave operation. We report here a new all-fiber traveling-wave ring laser with a Mach-Zehnder interferometer (MZI) that was used to provide spectral-selective coupling into the ring cavity and to ensure unidirectional light propagation without nonreciprocal elements.

© 1993 Optical Society of America