Granted Patent B2

US 12,564,047 · App. 18/123,170 · Granted Feb 24, 2026

Inventor: Subal Sahni (La Jolla, CA)

Assignee: Celestial AI Inc.

H01L23/34G02F1/0157H01L25/167

Abstract

Claims (37)

1 . A thermal control system comprising:

a semiconductor having an optical layer stacked with an electrical layer, the semiconductor partitioned into an electrical-only region and an optoelectrical region;

one or more nodes in the optoelectrical region, each of the one or more nodes residing in the optical layer and the electrical layer, a first portion of each of the one or more nodes residing in the optical layer and having at least one optical modulator and one or more heat-producing elements residing in the electrical layer and radiating heat toward the optical layer;

a temperature sensing region in a second portion of each of the one or more nodes, the temperature sensing region having a temperature sensor therein for sending a thermal signal to the electrical-only region, the thermal signal associated with a current temperature of the at least one optical modulator; and

a controller in the electrical-only region having an electrical interconnect to each of the one or more nodes for receiving the thermal signal from the temperature sensor and for sending a new voltage signal to the optoelectrical region based on the thermal signal.

2 . The thermal control system of claim 1 , wherein the at least one optical modulator is selected from a group consisting of an electro-absorption modulator (EAM) and a quantum confined stark effect (QCSE) electro-absorptive modulator.

3 . The thermal control system of claim 1 , wherein the new voltage signal is a negative DC bias voltage that is associated with a value of the thermal signal.

4 . The thermal control system of claim 1 , wherein the at least one optical modulator has an anode and a cathode and wherein the controller sends an AC swing signal to the cathode and the new voltage signal to the anode.

5 . The thermal control system of claim 1 , further comprising a table including a plurality of voltage values associated with a plurality of temperatures, wherein the controller selects a voltage value for the new voltage signal using the table and the current temperature.

6 . The thermal control system of claim 1 , further comprising a function for computing the new voltage signal using a product of the current temperature and an activation function.

7 . The thermal control system of claim 1 , wherein the one or more heat-producing elements are selected from a group consisting of central processing units (CPUs), graphics processing units (GPUs), memory units, message routers, tensor engines, digital neural networks, field-programmable gate arrays (FPGAs), and processing elements.

8 . A system-in-package (SIP) comprising:

a photonic integrated circuit (PIC);

an electronic integrated circuit (EIC) having an electrical connection with the PIC;

a node having a first portion of the node residing in the EIC and a second portion of the node residing in the PIC;

a plurality of heat-producing elements in the first portion of the node that radiates heat toward the second portion of the node, thereby causing a thermal change in the second portion of the node;

a plurality of optical modulators in the second portion of the node; and

a temperature sensing region in the second portion of the node for sending a current temperature to a controller, wherein the controller sends a first signal to each of the plurality of optical modulators based on the current temperature.

9 . The SIP of claim 8 , wherein the first signal is a DC bias voltage signal.

10 . The SIP of claim 8 , wherein each of the plurality of optical modulators includes a cathode and an anode, and wherein the first signal is sent to the anode of each of the plurality of optical modulators.

11 . The SIP of claim 10 , wherein the controller is further configured to send a second signal to the cathode of each of the plurality of optical modulators, the second signal comprising an AC swing signal.

12 . The SIP of claim 10 , wherein the controller sends an AC swing signal to the cathode of the plurality of optical modulators.

13 . A method for controlling a thermal variable associated with a plurality of optical components, comprising:

applying a first signal to a cathode of each of the plurality of optical components;

applying a second signal to an anode of each of the plurality of optical components;

sensing a temperature in a region associated with the plurality of optical components;

receiving a current temperature associated with the region;

determining when to initiate a thermal control over the plurality of optical components using the current temperature; and

wherein when a first one of the plurality of optical components is an inter-chip modulator, obtaining a first voltage and sending the first voltage to the anode of the inter-chip modulator;

wherein when a second one of the plurality of optical components is an intra-chip modulator, obtaining a second voltage and sending the second voltage to the anode of the intra-chip modulator, the second voltage has a different value than the first voltage.

14 . The method of claim 13 , wherein determining when to initiate the thermal control over the plurality of optical components is performed using a control circuit.

15 . The method of claim 13 , wherein the second signal is a DC bias voltage signal.

16 . The method of claim 13 , wherein the first signal comprises an AC swing signal.

17 . The method of claim 14 , wherein the plurality of optical components is selected from a group consisting of electro-absorption modulators (EAM) and quantum confined stark effect (QCSE) electro-absorptive modulators.

18 . The method of claim 13 , further comprising a table including a plurality of voltage values associated with a plurality of temperatures, wherein determining when to initiate the thermal control over the plurality of optical components further comprises accessing the table.

19 . The method of claim 13 , wherein sending the first voltage and the second voltage comprise selecting one or more rows in a table and obtaining a value from one or more columns associated with the one or more rows.

20 . The method of claim 13 , further comprising one or more functions, wherein sending the first voltage to the anode of the inter-chip modulator and sending the second voltage to the anode of the inter-chip modulator comprise calculating the first voltage and the second voltage by multiplying the current temperature with an activation function.

Assignments (2)

Continuity (3)

References Cited (367)