# US 12,113,576 B2 · Transmitter circuit, optical module, and communications device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,113,576 B2 - Document ID: US12113576B2 - Status: Granted - Kind: B2 - Application number: 18/070,126 - Filed: 2022-11-28 - Published: 2023-04-13 - Granted: 2024-10-08 - Earliest claimed: 2020-05-29 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Zhiwei Li; Zhongzhi Shang; Wenjun Shi - Web page: https://patentgrep.com/patent/US12113576B2 ## CPC - H01S 5/0427: {for applying modulation to the laser} - H04B 10/504: {using direct modulation} - H01S 5/042: Electrical excitation {; Circuits therefor (monolithically integrated laser drive components H01S5/0261)} - H04B 10/40: Transceivers - H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL - H04B: TRANSMISSION ## Abstract A transmitter circuit, an optical module, and a communications device is disclosed. A transmitter circuit includes a driver and a directly modulated laser DML. A positive electrode of the driver is connected to a positive electrode of the DML, a negative electrode of the DML is connected to a voltage terminal, and the negative electrode of the DML is connected to a ground terminal through a capacitor. The driver is configured to generate a drive current based on an input signal, and output the drive current to the DML through the positive electrode of the driver. The DML inputs a first part of current of the drive current to the ground terminal through the capacitor, and the DML inputs a second part of current of the drive current to the voltage terminal. ## Claims ### Claim 1 A transmitter circuit, comprising a driver and a directly modulated laser (DML), wherein a positive electrode of the driver is connected to a positive electrode of the DML, a negative electrode of the DML is connected to a voltage terminal, and the negative electrode of the DML is connected to a ground terminal through a capacitor; the driver is configured to generate a drive current based on an input signal, and output the drive current to the DML through the positive electrode of the driver; and the DML is configured to output a first part of current of the drive current to the ground terminal through the capacitor, and output a second part of current of the drive current to the voltage terminal. ### Claim 2 (depends on 1) The transmitter circuit according to claim 1, wherein the positive electrode of the driver and the ground terminal are respectively located on two sides of the driver, and the positive electrode of the driver is connected to the positive electrode of the DML through a first bonding wire. ### Claim 3 (depends on 1) The transmitter circuit according to claim 1, wherein the positive electrode of the driver and the ground terminal are located on a same side of the driver, and the positive electrode of the driver extends to a transition layer outside the driver and is connected to the positive electrode of the DML through a first bonding wire. ### Claim 4 (depends on 1) The transmitter circuit according to claim 1, wherein the capacitor is a surface mount capacitor, and the surface mount capacitor is soldered between the negative electrode of the DML and the ground terminal. ### Claim 5 (depends on 1) The transmitter circuit according to claim 1, wherein the voltage terminal is connected to an external power supply. ### Claim 6 (depends on 1) The transmitter circuit according to claim 1, wherein the voltage terminal is the negative electrode of the driver. ### Claim 7 (depends on 1) The transmitter circuit according to claim 1, wherein a voltage of the voltage terminal is zero. ### Claim 8 (depends on 7) The transmitter circuit according to claim 7, wherein the positive electrode of the driver is connected in series to the positive electrode of the DML through a first switch. ### Claim 9 (depends on 7) The transmitter circuit according to claim 7, wherein the negative electrode of the DML is connected in series to the voltage terminal through a second switch. ### Claim 10 An optical module, comprising a transmitter circuit and a receiver circuit, the transmitter circuit comprising a driver and a directly modulated laser (DML), wherein a positive electrode of the driver is connected to a positive electrode of the DML, a negative electrode of the DML is connected to a voltage terminal, and the negative electrode of the DML is connected to a ground terminal through a capacitor; the driver is configured to generate a drive current based on an input signal, and output the drive current to the DML through the positive electrode of the driver; and the DML is configured to output a first part of current of the drive current to the ground terminal through the capacitor, and output a second part of current of the drive current to the voltage terminal. ### Claim 11 (depends on 10) The optical module according to claim 10, wherein the positive electrode of the driver and the ground terminal are respectively located on two sides of the driver, and the positive electrode of the driver is connected to the positive electrode of the DML through a first bonding wire. ### Claim 12 (depends on 10) The optical module according to claim 10, wherein the positive electrode of the driver and the ground terminal are located on a same side of the driver, and the positive electrode of the driver extends to a transition layer outside the driver and is connected to the positive electrode of the DML through a first bonding wire. ### Claim 13 (depends on 10) The optical module according to claim 10, wherein the capacitor is a surface mount capacitor, and the surface mount capacitor is soldered between the negative electrode of the DML and the ground terminal. ### Claim 14 (depends on 10) The optical module according to claim 10, wherein the voltage terminal is connected to an external power supply. ### Claim 15 (depends on 10) The optical module according to claim 10, wherein the voltage terminal is the negative electrode of the driver. ### Claim 16 (depends on 10) The optical module according to claim 10, wherein the positive electrode of the driver is connected in series to the positive electrode of the DML through a first switch. ### Claim 17 (depends on 10) The optical module according to claim 10, wherein the negative electrode of the DML is connected in series to the voltage terminal through a second switch. ### Claim 18 A package, comprising: a capacitor; a driver; and a directly modulated laser (DML), wherein: a positive electrode of the driver is connected to a positive electrode of the DML, a negative electrode of the DML is connected to a voltage terminal, the negative electrode of the DML is connected to a ground terminal through the capacitor, and the capacitor is surface mounted to the DML; the driver is configured to generate a drive current based on an input signal, and output the drive current to the DML through the positive electrode of the driver; and the DML is configured to output a first part of current of the drive current to the ground terminal through the capacitor, and output a second part of current of the drive current to the voltage terminal. ### Claim 19 (depends on 18) The package according to claim 18, wherein the positive electrode of the driver and the ground terminal are respectively located on two sides of the driver, and the positive electrode of the driver is connected to the positive electrode of the DML through a first bonding wire. ### Claim 20 (depends on 18) The package according to claim 18, wherein the positive electrode of the driver and the ground terminal are located on a same side of the driver, and the positive electrode of the driver extends to a transition layer outside the driver and is connected to the positive electrode of the DML through a first bonding wire.