Enhanced received signal power indicators for optical receivers and transceivers, and methods of making and using the same
View Patent ↗An optical transceiver and/or optical network, and methods of monitoring optical transceivers, may be useful for increasing the dynamic range and/or determining the received signal strength and/or link budget of the optical transceiver and/or a different optical transceiver in the optical network. The circuitry generally comprises a photodiode configured to generate a first current responsive to an optical signal, a current mirror configured to produce a second current equal or proportional to the first current, and a nonlinear element configured to produce a first voltage from the first current.
1. A circuit, comprising:
(a) a photodiode configured to generate a first current and an electrical signal responsive to an optical signal;
(b) a current mirror configured to produce a second current equal to or proportional to the first current;
(c) a nonlinear element configured to produce a first voltage from the second current;
(d) an amplifier configured to produce a second voltage in response to the electrical signal; and
(e) a processor coupled to receive the first voltage and the second voltage, configured to determine or calculate a link budget from the first voltage and the second voltage.
2. The circuit of claim 1 , wherein the nonlinear element comprises a logarithmic amplifier.
3. The circuit of claim 1 , wherein the nonlinear element comprises a gain amplifier.
4. The circuit of claim 1 , wherein the nonlinear element comprises a first diode.
5. The circuit of claim 1 , wherein the nonlinear element comprises a segmented linear amplifier.
6. The circuit of claim 1 , wherein the nonlinear element comprises a segmented nonlinear resistor.
7. The circuit of claim 6 , wherein the segmented nonlinear resistor comprises a plurality of parallel resistive segments.
8. The circuit of claim 6 , wherein the segmented nonlinear resistor comprises one or more diodes and a plurality of resistors.
9. The circuit of claim 8 , wherein the segmented nonlinear resistor comprises:
a first resistive segment comprising a first resistor; and
a second resistive segment, comprising a second resistor and a second diode in series with the second resistor.
10. An optical transceiver, comprising an optical receiver including the circuit of claim 1 and a laser diode coupled to the processor, wherein the photodiode is configured to receive optical information from a remote transceiver.
11. The circuit of claim 10 , wherein the amplifier comprises a transimpedance amplifier.
12. The circuit of claim 10 , further comprising a laser driver circuit coupled to the laser diode and the processor.
13. The circuit of claim 1 , wherein the nonlinear element comprises a passive nonlinear device and an operational amplifier configured to determine a voltage differential across the nonlinear device.
14. The circuit of claim 13 , wherein passive nonlinear device comprises a diode.
15. A circuit, comprising:
a) a photodiode configured to generate, in response to an optical signal, (i) an electrical signal and (ii) a first current;
b) a nonlinear element coupled to the photodiode and configured to produce a first voltage from the first current;
c) a first amplifier configured to amplify the electrical signal and produce a second voltage; and
d) a processor coupled to receive the first voltage and the second voltage, configured to determine or calculate a link budget from the first voltage and the second voltage.
16. The circuit of claim 15 , wherein the nonlinear element comprises:
a) a passive nonlinear device coupled between a terminal of the photodiode and a power supply; and
b) an operational amplifier configured to detect a voltage differential across the passive nonlinear device and output the first voltage therefrom.
17. The circuit of claim 16 , wherein the passive nonlinear device comprises a diode.
18. The circuit of claim 16 , further comprising a second amplifier receiving an output of the first amplifier.
19. A method for monitoring one or more optical transceivers, the method comprising:
(a) receiving and/or sending one or more optical signals;
(b) converting the optical signal(s) into a first current and an electrical signal using a current mirror;
(c) converting the first current into a first voltage using a nonlinear element;
(d) producing a second voltage from the electrical signal using an amplifier; and
(e) calculating a link budget using the first voltage and the second voltage.
20. The method of claim 19 , further comprising calculating the received signal strength, wherein the method further comprises transmitting a first flag and/or state corresponding to a value range of the received signal strength to a network or host.
21. An optical transceiver, comprising:
a) an optical receiver including the circuit of claim 1 , wherein the photodiode is configured to receive optical information from a remote transceiver; and
b) a transmitter, comprising a laser diode coupled to the processor.
22. The method of claim 20 , further comprising transmitting a second flag and/or state corresponding to a value range of the link budget to the network or host.