Novel optical fiber lasers

The most important area of activity in research into fiber lasers continues to be the erbium-doped fiber amplifier for optical communications systems; complementary activities include work on ultrafast erbium lasers, soliton transmission and narrow-linewidth/tunable lasers in the 1.5 μm band. The development of in-fiber Bragg gratings has contributed greatly to progress in these areas. In contrast, progress in optical fiber amplifiers at 1.3 μm has been slow, and the future for fiber-based amplifier technology at this and other wavelengths is uncertain. Of activities not related to communication, the development of new laser transitions in the 2–4 μm region has the most practical significance.