Anomalous dispersion in Er/sup 3+/ and Yb/sup 3+/-doped fibers

Abstract

In experimental and theoretical study of anomalous dispersion in Er/sup 3+/and Er/sup 3+/-Yb/sup 3+/-doped fibers has been developed. Anomalous time delay caused by both absorption and emission at 1.535 /spl mu/m has been theoretically calculated and experimentally measured. A pump power dependence of anomalous time delay in rare-earth-doped fibers has been theoretically calculated and experimentally investigated. It has been shown that pump power fluctuations lead to propagation time jitter in Er/sup 3+/-doped fiber amplifiers. The pulse interaction due to refractive index change caused by gain saturation is predicted. It has been shown that for Er/sup 3+/-doped fibers with SiO/sub 2/-GeO/sub 2/ core composition, the anomalous dispersion per 1-dB gain is twice that of fibers with SiO/sub 2/-Al/sub 2/O/sub 3/ core, which is caused by gain curve form difference. A scheme of mutual compensation of intrinsic fiber dispersion and anomalous dispersion caused by Er/sup 3+/ in the region 1.532-1.537 /spl mu/m has been suggested. >