Aspects are generally directed to receivers and methods for actively demodulating optical signals. In one example, a receiver includes an optical resonator to receive an optical signal, the optical resonator including an active optical medium interposed between first and second semi-reflective surfaces, where the active optical medium is configured to accumulate resonant optical signal energy inside the optical resonator based on the received optical signal, the second semi-reflective surface is positioned to emit output optical signal energy, and the optical resonator is configured to disturb the output optical signal energy in response to a variation in the received optical signal. The receiver may further include a detector configured to detect the disturbance in the output optical signal energy, and a pump source coupled to the active optical medium to excite the active optical medium to generate an optical gain in the received optical signal.

An optical analog-to-digital converter (O-ADC) converts an input optical signal (IOS) into an output digital signal. The O-ADC includes ADC stages, each of which can generate an electrical bit of the output digital signal and an optical bit. An ADC stage can include a photodetector, an ADC circuit, and an optical output circuit. The photodetector generates an analog electrical signal based on a portion of the IOS. The ADC circuit generates a digital electrical signal (electrical bit) based on the analog electrical signal and a reference analog electrical signal, which is based on a portion of a reference optical signal (ROS). The optical output circuit provides an output optical signal (OOS) (optical bit) based on the digital electrical signal and the portion of the ROS. Photodetectors of subsequent ADC stages generate analog electrical signals based further on an OOS from an optical output circuit of a previous respective ADC stage.

An optical analog-to-digital converter (O-ADC) converts an input optical signal (IOS) into an output digital signal. The O-ADC includes ADC stages, each of which can generate an electrical bit of the output digital signal and an optical bit. An ADC stage can include a photodetector, an ADC circuit, and an optical output circuit. The photodetector generates an analog electrical signal based on a portion of the IOS. The ADC circuit generates a digital electrical signal (electrical bit) based on the analog electrical signal and a reference analog electrical signal, which is based on a portion of a reference optical signal (ROS). The optical output circuit provides an output optical signal (OOS) (optical bit) based on the digital electrical signal and the portion of the ROS. Photodetectors of subsequent ADC stages generate analog electrical signals based further on an OOS from an optical output circuit of a previous respective ADC stage.