CN-122003638-A - Mismatch resistant thermal control loop for cascaded optical ring resonators

Abstract

An Integrated Circuit (IC) device includes an optoelectronic circuit having a first heater and a second heater, and a controller circuit having an input coupled to a photodiode of the optoelectronic circuit and an output coupled to the first heater and the second heater of the optoelectronic circuit, the controller circuit configured to determine an offset from a baseline heater control signal code based on a Transimpedance (TIA) control signal code of an input signal received from the photodiode, and provide a first heater control signal to the first heater and a second heater control signal to the second heater based on the offset of the optoelectronic circuit.

Inventors

• M. RAJ
• C.Xie
• P. Epad Yaya
• Y. Frans

Assignees

• 赛灵思公司

Dates

Publication Date

20260508

Application Date

20240830

Priority Date

20230930

Claims (15)

1. 1. An Integrated Circuit (IC) device, the IC device comprising: an optoelectronic circuit having a first heater and a second heater, and A controller circuit having an input coupled to a photodiode of the optoelectronic circuit and an output coupled to the first and second heaters of the optoelectronic circuit, the controller circuit configured to determine an offset from a baseline heater control signal code based on a Transimpedance (TIA) control signal code of an input signal received from the photodiode, and to provide a first heater control signal to the first heater and a second heater control signal to the second heater based on the offset of the optoelectronic circuit.
2. 2. The IC device of claim 1, wherein the controller circuit further comprises: A TIA circuit having a first input coupled to the photodiode and an output coupled to an input of a limiter circuit, and A control code circuit having an input coupled to an output of the clipping circuit, the control code circuit configured to output a TIA control signal to an input of a first digital-to-analog converter (DAC), a first heater control signal code to a second DAC, and a second heater control signal code to a third DAC, the TIA circuit configured to cancel a Direct Current (DC) component of the input signal from the photodiode based on the TIA control signal, the second DAC configured to output the first heater control signal to the first heater based on the first heater control signal code, and the third DAC configured to output the second heater control signal to the second heater based on the second heater control signal code.
3. 3. The IC device of claim 2, wherein the control code circuit is configured to determine that the input signal comprises a convex shape or a flat shape based on the input signal having one maximum TIA control signal code.
4. 4. The IC device of claim 3, wherein the control code circuit is configured to increase the first heater control signal code and to stop increasing the first heater control signal code as the offset based on the one maximum TIA control signal code.
5. 5. The IC device of claim 4, wherein the control code circuit is configured to: increasing the first heater control signal code, and The second heater control signal code is incremented and stored as the offset based on the one maximum TIA control signal code stopping incrementing.
6. 6. The IC device of claim 2, wherein the control code circuit is configured to determine that the input signal has a concave shape based on the input signal having two largest TIA control signal codes, and to determine one smallest TIA control signal code located between the two largest TIA control signal codes.
7. 7. The IC device of claim 6, wherein the control code circuit is configured to increase the first heater control signal code and to stop increasing the first heater control signal code as the offset based on the one minimum TIA control signal code.
8. 8. The IC device of claim 6, wherein the control code circuit is configured to: increasing the first heater control signal code, and The second heater control signal code is incremented and the incrementing of the second heater control signal code is stopped based on the one minimum TIA control signal code to be stored as the offset.
9. 9. The IC device of claim 2, wherein the first heater control signal and the second heater control signal are provided differently from each other.
10. 10. A controller circuit, the controller circuit comprising: a Transimpedance (TIA) circuit having an input coupled to a photodiode of a photo-electric circuit and an output coupled to a control code circuit configured to generate a voltage signal based on an input signal received from the photodiode, the control code circuit comprising: A TIA control circuit having an input connected to the output of the TIA circuit, and A heater circuit having an input coupled to an output of the TIA control circuit, and a first output coupled to a first heater of the optoelectronic circuit, and a second output coupled to a second heater of the optoelectronic circuit, the heater circuit configured to determine an offset from a baseline heater control signal code of the optoelectronic circuit based on the voltage signal received from the TIA circuit, and provide a first heater control signal to the first heater and a second heater control signal to the second heater based on the offset of the optoelectronic circuit.
11. 11. The controller circuit of claim 10, wherein the control code circuit is configured to adjust the first heater control signal and the second heater control signal to determine the offset.
12. 12. The controller circuit of claim 11, wherein the heater circuit is configured to determine that the input signal comprises a concave shape, a convex shape, or a flat shape based on the voltage signal.
13. 13. A method for operating an integrated circuit device, the method comprising: Determining a shape of an input signal received from the photodiode by a controller circuit having an input coupled to the photodiode of the optoelectronic circuit, a first output coupled to a first heater of the optoelectronic circuit, and a second output coupled to a second heater of the optoelectronic circuit, and An offset from a baseline heater control signal code of the optoelectronic circuit is determined by the controller circuit based on the shape of the input signal, and a first heater control signal is provided to the first heater and a second heater control signal is provided to the second heater based on the offset of the optoelectronic circuit.
14. 14. The method of claim 13, further comprising determining that the input signal comprises a convex shape or a flat shape based on the input signal having one maximum TIA control signal code.
15. 15. The method of claim 14, further comprising at least one or more selected from the group consisting of: (A) Increasing the first heater control signal and storing the first heater control signal as the offset when the one maximum TIA control signal code stops increasing; (B) Increasing the first heater control signal, and Increasing the second heater control signal and storing the second heater control signal as the offset when the one maximum TIA control signal code stops increasing: (C) Determining that the input signal has a concave shape based on the input signal having two largest TIA control signal codes, and Determining a minimum TIA control signal code located between the two maximum TIA control signal codes; (D) Determining that the input signal has a concave shape based on the input signal having two largest TIA control signal codes; Determining a minimum TIA control signal code located between said two maximum TIA control signal codes, and Increasing the first heater control signal and storing the first heater control signal as the offset when the one minimum TIA control signal code stops increasing, and (E) Determining that the input signal has a concave shape based on the input signal having two largest TIA control signal codes; Determining a minimum TIA control signal code located between the two maximum TIA control signal codes; increasing the first heater control signal code, and The second heater control signal code is incremented and stored as the offset when the one minimum TIA control signal code stops incrementing.

Description

Mismatch resistant thermal control loop for cascaded optical ring resonators Government license rights The present invention was completed under U.S. government support under contract number HR0011-19-3-0004 awarded by the national Defense Advanced Research Program Agency (DARPA). The united states government has certain rights in this invention. Technical Field Examples of the present disclosure generally relate to temperature locked loops for optical elements having temperature-dependent responses. Background Optics have been used for communications, such as communications over fibre channel. Optical communication can achieve low loss physical channels and very high speeds. Similar to electrical devices, some optical devices may be used to process or filter signals, even optical signals. However, some optical devices may have features that are not present or are less important in electrical devices. Further developments and implementations of optics in future technologies may require addressing these features. Disclosure of Invention In one or more examples, an Integrated Circuit (IC) device includes an optoelectronic circuit having a first heater and a second heater, and a controller circuit having an input coupled to a photodiode of the optoelectronic circuit and an output coupled to the first heater and the second heater of the optoelectronic circuit, the controller circuit configured to determine an offset from a baseline heater control signal code based on a Transimpedance (TIA) control signal code of an input signal received from the photodiode, and provide a first heater control signal to the first heater and a second heater control signal to the second heater based on the offset of the optoelectronic circuit. In one or more examples, a controller circuit includes a Transimpedance (TIA) circuit having an input coupled to a photodiode of the optoelectronic circuit and an output coupled to a control code circuit configured to generate a voltage signal based on an input signal received from the photodiode, the control code circuit including a TIA control circuit having an input connected to an output of the TIA circuit, and a heater circuit having an input coupled to an output of the TIA control circuit and a first output coupled to a first heater of the optoelectronic circuit and a second heater of the optoelectronic circuit, the heater circuit configured to determine an offset from a baseline heater control signal code of the optoelectronic circuit based on the voltage signal received from the TIA circuit and to provide the first heater control signal to the first heater and the second heater control signal based on the offset of the optoelectronic circuit. In one or more examples, a method for operating an integrated circuit device includes determining, by a controller circuit, a shape of an input signal received from a photodiode, the controller circuit having an input coupled to the photodiode of the optoelectronic circuit, a first output coupled to a first heater of the optoelectronic circuit, and a second output coupled to a second heater of the optoelectronic circuit, and determining, by the controller circuit, an offset from a baseline heater control signal code of the optoelectronic circuit based on the shape of the input signal, and providing a first heater control signal to the first heater and a second heater control signal to the second heater based on the offset of the optoelectronic circuit. Drawings So that the manner in which the above recited features can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to exemplary embodiments, some of which are illustrated in the appended drawings. It should be noted, however, that the drawings illustrate only typical example implementations and are therefore not to be considered limiting of its scope. Fig. 1 illustrates an Integrated Circuit (IC) device in accordance with one or more examples. FIG. 2 is a more detailed schematic diagram of the schematic diagram of FIG. 1 according to one or more examples Fig. 3 illustrates a flow diagram illustrating a method for calibrating an input signal from an optoelectronic circuit in accordance with one or more examples. FIG. 4 illustrates a graph of an input signal in accordance with one or more examples. Fig. 5 illustrates a flow diagram illustrating a method for calibrating an optical element having a convex frequency response in accordance with one or more examples. FIG. 6 illustrates a graph of an example input signal having a convex shape in accordance with one or more examples. Fig. 7 illustrates a flow diagram illustrating a method for calibrating an optical element having a flat shape frequency response in accordance with one or more examples. FIG. 8 illustrates a graph of an example input signal having a flat shape in accordance with one or more examples. Fig. 9 illustrates a flow diagram illustrating a method for calibrati