LASER PIGTAIL FIBER WITH INHERENT ATTENUATION CHARACTERISTIC

摘要

A fiber optic telecommunication system (900) with a pump laser (910) and an optical amplifier (930) is designed to stabilize the pump laser (910) while preventing back reflections from the pump laser (910) into the optical amplifier (930). The pump laser (910) emits radiation at a shorter wavelength, while the optical amplifier (930) emits radiation at a longer wavelength. An optical fiber (920) is provided to connect the devices which has an ultraviolet photosensitive core, a low attenuation single mode wavelength region and a very high attenuation, longer wavelength region. The photosensitive core allows a weak Bragg grating (970) to be written into the fiber (920), to stabilize the pump laser (910). Apparent fundamental mode cutoff is accomplished with a depressed well design to attenuate the unwanted back reflections from the pump laser (910) into the amplifier (930). The pump laser (910) is also protected from longer wavelength signal amplifier or signal laser radiation.