Novel fiber amplifier technology

We must expand the operating wavelength range of the optical fiber amplifier if we are to achieve a large scale DWDM and CWDM optical communication system with high performance levels. In this report, we introduce the S-band amplification technique with a Tm 3+ -doped fluoride fiber amplifier and an Er 3+ -doped fiber amplifier, and a fiber Raman amplification technique with a wider application range realized by using tellurite fiber. Furthermore, we describe the use of our proposed wide optical fiber amplifiers in an 8-channel CWDM communication system.