Fast-response, wide-dynamic-range optical equalisation based on silicon photonic platform

Fast optical power equalisation using a monolithic integrated germanium photodetector and a silicon variable optical attenuator on a compact silicon photonic platform is demonstrated. With an external electronic feedback circuit, the output power of the device is stabilised within a residual deviation of 2.7 dB for 22 dB input power variation. For a surge pulse, a sudden input power increase of over 16 dB can be suppressed within 50 ns for a 3 dB recovery.