OFDM direct detection using a balanced receiver

An optical receiver, comprising:

• an optical filter having an input and first and second outputs, the input being configured to receive an input optical signal, which includes a carrier and a plurality of subcarriers, the optical filter supplying a first output optical signal including the carrier at the first output and a second output optical signal including the plurality of subcarriers at the second output, the carrier having a first frequency, and each of the plurality of subcarriers having a corresponding one of a plurality of second frequencies;
• an optical coupler having first and second inputs and first and second outputs, the first input of the optical coupler being configured to receive the first output optical signal and the second input of the optical coupler being configured to receive the second output optical signal, a third output optical signal being supplied from the first output of the optical coupler and a fourth output optical signal being supplied from the second output of the optical coupler;
• a first photodetector configured to receive the third output optical signal and generate a first electrical signal in response to the third output optical signal;
• and
• a second photodetector configured to receive the fourth output optical signal and generate a second electrical signal in response to the fourth output optical signal.