Smart optical transceiver having integrated optical dying gasp function

1. An optical transceiver, comprising:

an electric terminal configured to receive power from a host equipment and to provide a power supply voltage to the optical transceiver;

a power failure monitor circuit integrated in the optical transceiver, where the power failure monitor circuit is configured to detect an imminent loss of the power supply voltage, wherein the power failure monitor circuit is configured to produce a dying-gasp control signal when such imminent loss of power supply voltage is detected or when a disabling control signal is received from the host equipment;

a driver configured to receive output data and the dying-gasp control signal; and

an optical transmitter powered by the power supply voltage and configured to emit a first optical signal under the control of the driver, wherein the driver and the optical transmitter are configured to produce an optical-layer dying-gasp signal in response to the dying-gasp control signal.

2. The optical transceiver of claim 1 , wherein the driver is configured to modulate an envelope of the first optical signal to produce a sequence of optical pulses in the first optical signal, the sequence of optical pulses comprising the first dying gasp signal.

3. The optical transceiver of claim 2 , wherein the sequence of optical pulses comprises alternate on and off in the optical power of the first optical signal.

4. The optical transceiver of claim 2 , wherein the driver comprises an enable/disable control configured to turn on or off the output of the optical transmitter, wherein the dying-gasp control signal controls to enable/disable control to turn on or off the output power of the optical transmitter to produce the sequence of optical pulses.

5. The optical transceiver of claim 2 , wherein a time interval between adjacent optical pulses is in a range between 0.01 ms and 5 ms.

6. The optical transceiver of claim 1 , wherein the power failure monitor circuit comprises:

a voltage comparator configured to compare the power supply voltage with a predetermined threshold voltage; and

a dying gasp signal generator configured to generate the dying-gasp control signal when the power supply voltage falls below the predetermined threshold voltage.

7. The optical transceiver of claim 6 , wherein the driver and the optical transmitter are configured to modulate an envelope of the first optical signal when the voltage comparator detects that the power supply voltage falls below the predetermined threshold voltage.

8. The optical transceiver of claim 6 , wherein the optical transceiver operates at a nominal power supply voltage under normal operations, wherein the optical transceiver fails to function when the power supply voltage falls below a minimum voltage, wherein the predetermined threshold voltage is between the nominal power supply voltage and the minimum voltage.

9. The optical transceiver of claim 1 , wherein the driver and the optical transmitter are configured to modulate an envelope of the first optical signal when the power failure monitor circuit detects an imminent loss of the power supply voltage.

10. The optical transceiver of claim 1 , wherein the disabling control signal from the host equipment is configured to control the driver to stop the optical transmitter from emitting the first optical signal.

11. The optical transceiver of claim 1 , further comprising a reception electrical interface configure to receive a first electrical signal, wherein the optical transmitter is configured to emit the first optical signal in response to the first electrical signal, wherein the reception electrical interface is in compliance with a standard selected from the group consisting of SFF, SFP, XFP, and SFP+.