Abstract
An erbium-doped fiber amplifier installed inside an optical fiber cable is reported. This optical cable amplifier is mechanically flexible as the result of using a flexible stainless steel tube and wire mesh as the amplifier cavity and outer cover, respectively. The amplifier is pumped with a 0.98μm laser diode to reduce both the electric driving power and the wavelength dependence of optical gain. Backward pumping is used to obtain a high optical output power. A gain of 27.5dB and a maximum optical output power of + 10dBm have been successfully realized. The wavelength dependence of the optical gain was 2.1dB between 1540nm and 1560nm. A two-channel optical cable amplifier with two EDFAs in the cable is also described. The noise figure of the amplifiers was approximately 6dB and the output power dependence on ambient temperature change was less than ±0.2dB between 20°C and 60°C.
