Title :
Gain saturation in fiber distributed feedback lasers
Author :
Szczepanski, Pawel ; Sklodowska, Malgorzata ; Wolinski, Wieslaw
Author_Institution :
Inst. of Microelectron. & Optoelectron., Warsaw Univ. of Technol., Poland
fDate :
3/1/1991 12:00:00 AM
Abstract :
Systematic numerical studies of the nonlinear operation of a fiber distributed feedback (DFB) Nd:YAG laser are presented. An approximate formula relating small-signal gain to output power and the parameters of the structure for this kind of laser is derived. Characteristics revealing saturation effects for weak and strong coupling regions are presented. The fiber DFB structure provides the discrimination between the different kinds of transverse modes. An interesting behavior of the laser characteristics is revealed. For large coupling strength the longitudinal mode spectrum is inversed to the one observed at the threshold or to the one above the threshold for weak coupling. This mode inversion strongly depends on the output power level and the normalized loss coefficient. Similar phenomena are observed for the transverse mode
Keywords :
distributed feedback lasers; fibre lasers; laser modes; neodymium; optical communication equipment; optical saturation; DFB lasers; Nd:YAG laser; YAG:Nd; YAl5O12:Nd; coupling strength; fiber DFB structure; fiber distributed feedback lasers; gain saturation; laser characteristics; longitudinal mode spectrum; mode inversion; nonlinear operation; normalized loss coefficient; output power level; saturation effects; small-signal gain; strong coupling regions; transverse modes; weak coupling regions; Distributed feedback devices; Fiber lasers; Laser feedback; Laser theory; Optical fiber communication; Optical fiber theory; Optical fibers; Power lasers; Pump lasers; Waveguide lasers;
Journal_Title :
Lightwave Technology, Journal of
