A modular bidirectional optical amplification system includes a multiwavelength dual amplifier building block, a multiwavelength unidirectional booster amplifier BB, a unidirectional and a bidirectional Optical Service Channel (OSC) BB, an Intelligent Optical Terminal Accessway (IOTA) module, and an interleaved filter BB. The dual amplifier BB is available in a C-band version, an E-band version and a hybrid version, and provides unidirectional or bidirectional multichannel amplification. The booster amplifier is available in a C-band version, an E-band version and in a booster plus variant;. one for the C-band and one for E-band. The unidirectional and bidirectional OSC BBs provide a means for OAM&P functionality to the optical network. The IOTA BB provides multiplexing and demultiplexing, and the filter BB provides separation of the signal into grid-1 and grid-2 channels.