Tunable ASE filters

The advantages of low cost amplifier solutions in single-channel link extender or loss compensator systems cannot be fully realized unless the ASE noise around the signal peak is removed. Doing so requires a cost-effective solution with high performance, including low insertion loss (<-2.5dB), low PDL (<-0.25dB), low power operation (<200mW), and fast tuning (<1sec). We have successfully fabricated and packaged a tunable ASE filter into a small form-factor 2-port package which meets these requirements. We obtain filter properties at both the chip and package-levels and examine filter performance operating under optically open and closed loop control.