Twin coupler for optical amplifier, couplers fused and tapered by different amounts

摘要

An optical amplifier system includes a multimode pump laser 3500. Energy from laser 3500 is coupled into a signal fibre 3100 at two couplers 3600 and 3700. The second coupler 3700 uses energy not transferred into fibre 3100 by first coupler 3600. The amount of energy transferred by the second coupler is dependent on the amount of energy transferred by the first coupler. The couplers are formed by fusion and tapering operations, these operations being carried out while a multimode laser is coupled to the pump fibre. The fusion and tapering operations are terminated when it is determined that maximum multimode optical signal transfer is obtained.