High gain (21 dB) packaged semiconductor optical amplifiers

Record gains of 19 to 21 dB have been obtained reproducibly using a type of semiconductor optical amplifier package incorporating of 1.3-μm tilted-facet ridge amplifier. The authors describe the package, which utilizes a novel two-temperature-zone design to achieve a process for independent soldering of the input and output fibers. The process permits stable and efficient fiber coupling to both facets, and permits reworking of less-than-optimum fiber attachments. Since the thermoelectric coolers used to control the amplifier´s temperature also serve as the heat source used for soldering, the package contributes to its own self-assembly. It is noted that simple, highly manufacturable high-gain packages, such as these, will be invaluable to the development of branched or long-distance optical links