Abstract

Single-mode distributed feedback (DFM) erbium-doped fiber lasers, based on directly UV-written Bragg gratings in fibers were demonstrated recently.^1–3 A π/2 phase-shift, introduced in the central part of the structure, results in robust single longitudinal-mode operation with high stability and low lasing threshold. These characteristics combined with optical fiber compatibility, compact size, and wavelength setability make fiber DFB lasers highly attractive sources for externally modulated high bit-rate^4,5 and wavelength-division multiplexed (WDM) systems.

© 1996 Optical Society of America