Athermal optical gain block in C-band by serial concatenations of erbium-doped antimony oxide silica glass fiber

We report a new novel technique to suppress the temperature-dependent gain (TDG) of erbium-doped fiber amplifier in the C-band by providing a composite optical gain block, conventional erbium-doped fiber (EDF) serially concatenated with Sb-doped silica EDF. Compared with conventional EDFs, Sb-doped silica EDF showed an opposite TDG coefficient in the C-band. Detailed experimental athermalization schemes are reported for various concatenating configurations. The temperature-dependent optical gain variation was suppressed within /spl plusmn/0.35 dB for the temperature range of -40/spl deg/C to +80/spl deg/C from 1530 to 1560 nm.