Greater than 30-dB gain at 1500nm in S-band erbium-doped silica fiber with distributed ASE suppression

Abstract

S-band amplification with >30 dB peak gain at 1500 nm, >20 dB gain for wavelengths between 1475 nm and 1520 nm, and 5 dB noise figure is demonstrated in Erbium-doped Alumino-germanosilicate fiber. Using standard MCVD processing and solution doping, we combined a depressed-cladding fiber design with erbium doping to create a new type of gain fiber. A fundamental mode cutoff near 1530 nm provides distributed suppression of C-band amplified spontaneous emission, thereby enabling the high population inversion required for S-band gain. This type of S-band amplifier is compatible with standard fusion splicing techniques and is pumped by standard 980 nm pump lasers. In this talk, we will describe gain and noise characteristics for several amplifier architectures, gain saturation characteristics, and gain flattening.