Haruki Ogoshi, Seiji Ichino, Katsuya Kurotori
The spread and expansion of DWDM (Dense Wavelength Multiplexing) systems are going on keeping pace with various technology developments of optical amplifiers and, in particular, the bandwidth broadening of EDFAs (Erbium Doped Fiber Amplifier). In this technology area, gain-equalizing technology has been developed to flatten the gain peaks around 1532 nm, making available a wide range of wavelengths from 1530 to 1560 nm. Furthermore, development of gain-shift technology is under way, in which gain is shifted to the long wavelength band of 1570-1600 nm using long lengths of Erbium doped fibers (EDFs). This paper reports on the optical amplifier products that Furukawa Electric has developed so far: 1) modularized optical amplifier for 1530-1560 nm, which permits flexible control using a microprocessor; 2) desktop optical amplifier having a gain band shifted to 1570-1600 nm; and 3) ultra compact gain module for single channel use, which compensates for the loss due to passive components in DWDM systems, thus improving flexibility in the system design.