Reduction of temperature-dependent gain in L-band EDFA using antimony-aluminum codoped silica EDF

We report a novel technique to suppress the temperature-dependent gain (TDG) of an L-band erbium-doped fiber amplifier. The composite optical gain block consists of conventional L-band erbium-doped fiber (EDF) serially concatenated with a special EDF in a ternary glass composition, antimony-aluminum codoped silica that showed an opposite TDG coefficient in the L-band. The TDG variation of the composite gain block was suppressed to less than /spl plusmn/1.5 dB for a saturated gain of 15 dB between 1565 and 1605 nm, measured over a temperature range of -40/spl deg/C to +80/spl deg/C.