Optical module
The present disclosure provides an optical module comprising: a photoelectric conversion unit, a first demodulation circuit, and a second demodulation circuit; the first demodulation circuit and the second demodulation circuit are respectively connected to the photoelectric conversion unit; the photoelectric conversion unit is configured to convert the received optical signal into an electrical signal; the first demodulation circuit is configured to demodulate an electrical signal converted by the photoelectric conversion unit and generate a high-frequency electrical signal; the second demodulation circuit is configured to demodulate an electrical signal converted by the photoelectric conversion unit and generate a low-frequency electrical signal.
1. An optical module, comprising: a photoelectric conversion unit, a first demodulation circuit, and a second demodulation circuit; wherein
the first demodulation circuit and the second demodulation circuit are respectively connected to the photoelectric conversion unit;
the photoelectric conversion unit is configured to convert a received optical signal into an electrical signal;
the first demodulation circuit is configured to demodulate the electrical signal converted by the photoelectric conversion unit and generate a high-frequency electrical signal;
the second demodulation circuit is configured to demodulate the electrical signal converted by the photoelectric conversion unit and generate a low-frequency electrical signal.
2. The optical module according to claim 1 , wherein the first demodulation circuit comprises: a transimpedance amplifier and a high-pass filtering unit;
the transimpedance amplifier is connected to the photoelectric conversion unit;
the high-pass filtering unit is connected to the transimpedance amplifier;
the transimpedance amplifier is configured to convert a current signal output from the photoelectric conversion unit into a voltage signal and output the voltage signal;
the high-pass filtering unit is configured to perform high-pass filtering on the voltage signal output from the transimpedance amplifier.
3. The optical module according to claim 2 , wherein the high-pass filtering unit comprises: a limiting amplifier, a first capacitor and a second capacitor;
the first capacitor is connected to the transimpedance amplifier, and the second capacitor is connected to the transimpedance amplifier;
the limiting amplifier is connected to the first capacitor and the second capacitor, respectively;
the limiting amplifier is configured to perform high-pass filtering on the voltage signal output by the transimpedance amplifier along with the first capacitor and the second capacitor.
4. The optical module according to claim 1 , wherein the second demodulation circuit comprises: a current mirroring unit and a sample-and-hold circuit;
the current mirroring unit is connected to the photoelectric conversion unit;
the sample-and-hold circuit is connected to a first output end of the current mirroring unit;
the current mirroring unit is configured to receive a response current signal of the photoelectric conversion unit, perform low-pass filtering on the response current signal, and output a mirror current signal of the response current signal to the sample-and-hold circuit;
the sample-and-hold circuit is configured to convert the received mirror current signal into a voltage signal.
5. The optical module according to claim 4 , wherein the second demodulation circuit further comprises a high voltage driven circuit;
the high voltage driven circuit is connected to the current mirroring unit;
the high voltage driven circuit is configured to provide the photoelectric conversion unit with a reverse high voltage, so as to enable the photoelectric conversion unit to generate a response current signal.
6. The optical module according to claim 5 , wherein the second demodulation circuit further comprises: a received signal strength indication (RSSI) sampling circuit and a micro processing unit (MCU);
one end of the RSSI sampling circuit is connected to the current mirroring unit, and the other end of the RSSI sampling circuit is connected to the MCU;
the RSSI sampling circuit is configured to monitor the mirror current signal output by the current mirroring unit and send a monitoring result to the MCU.
7. The optical module according to claim 6 , wherein the current mirroring unit comprises a mirror current source;
a first input end of the mirror current source is connected to the high voltage driven circuit;
a first output end of the mirror current source is connected to the sample-and-hold circuit;
a second output end of the mirror current source is connected to the RSSI sampling circuit;
a third output end of the mirror current source is connected to the photoelectric conversion unit.
8. The optical module according to claim 4 , wherein the second demodulation circuit further comprises an operational amplifier;
the operational amplifier is connected to the sample-and-hold circuit;
the operational amplifier is configured to amplify the voltage signal output from the sample-and-hold circuit.
9. The optical module according to claim 5 , wherein the second demodulation circuit further comprises an operational amplifier;
the operational amplifier is connected to the sample-and-hold circuit;
the operational amplifier is configured to amplify the voltage signal output from the sample-and-hold circuit.
10. The optical module according to claim 6 , wherein the second demodulation circuit further comprises an operational amplifier;
the operational amplifier is connected to the sample-and-hold circuit;
the operational amplifier is configured to amplify the voltage signal output from the sample-and-hold circuit.
11. The optical module according to claim 7 , wherein the second demodulation circuit further comprises an operational amplifier;
the operational amplifier is connected to the sample-and-hold circuit;
the operational amplifier is configured to amplify the voltage signal output from the sample-and-hold circuit.
12. The optical module according to claim 1 , wherein the photoelectric conversion unit is an avalanche photo diode (APD) or a PIN photo diode.
13. The optical module according to claim 1 , wherein the low-frequency electrical signal is a signal that supports the Auxiliary Management and Control Channel (AMCC) function.