M-ARY frequency presence modulation communication system and method

An apparatus for transmitting and receiving encoded optical signals, the apparatus comprising:

• a data transmitter including:
• at least one optical emission device configured to output light energy as an optical beam having an operating bandwidth with at least one communication band,
• a frequency presence modulator configured to:
• spectrally segregate the bandwidth of the at least one communication band into plural channels, each channel having different wavelengths, and
• modulate the bandwidth to selectively produce an optical output signal with wavelengths that correspond to one or more of the channels, wherein a presence and absence of energy within channels of the communication band will constitute an information packet for data communication;
• an optical pathway for bi-directional optical communication over a common optical path for transmitting the optical output signal and for receiving an optical input signal;
• and
• a data receiver configured to receive the optical input signal from the optical pathway.