Photonic crystal distributed feedback fiber lasers with Bragg gratings

Two new types of optical fibers, where air-holes are running down their len gth, are considered for making fiber lasers with Bragg gratings, The mode a reas for pump and signal in these fiber lasers may be either larger or smal ler compared to the corresponding mode areas for fiber lasers based on stan dard step index fibers. This makes possible realization of fiber lasers wit h a low pump threshold (small mode area), and fiber lasers suitable for hig h-power applications (large mode area).