An optical module

Abstract

The present application provides an optical module, which is internally provided with a first laser diode and a second laser diode located on the same substrate, and the resonant cavities of the two laser diodes have an angle between them. A driving circuit is provided to drive the first laser diode to emit light, and when the first laser diode is controlled to be turned off, the second laser diode is driven to emit light. Since the second laser diode and the first laser diode are grown on a substrate, when the first laser diode is turned off, the second laser diode can transfer the heat generated when it is turned on to the first laser diode to stabilize the temperature of the first laser diode and reduce the temperature difference caused by the first laser diode being turned on and off, which causes the emission wavelength drift; at the same time, an angle is provided between the resonant cavities of the two laser diodes, so that the light emitted by the second laser diode can be reduced from entering the coupling lens, thereby avoiding the problem of the optical module's shutdown power not meeting the standard.

Description

Technical Field

[0001] The present application relates to the field of optical fiber communication technology, and in particular to an optical module. Background Art

[0002] In the field of optical communications, wavelength division multiplexing technology is a common bandwidth extension technology in the field of optical communications. Wavelength division multiplexing technology uses multiple lights with different wavelengths in the same optical fiber for data transmission, and uses the difference in light wavelength to distinguish different signal channels. Among them, orderly data transmission depends on the wavelength stability of the optical signal.

[0003] In PON (Passive Optical Network), the Optical Network Unit (ONU) usually realizes optical communication with the Optical Line Terminal (OLT) in the form of burst light emission. Specifically, the optical module in the optical network unit works in burst mode, that is, the laser chip in the optical module switches between emitting light and not emitting light. Since the laser chip generates heat during operation, the above working mode will cause the temperature of the laser chip to be different in different states. When the laser chip is working, the highest temperature reached by the laser chip is recorded as Ton; when the laser chip stops working, it does not emit light, so the temperature of the laser chip begins to decrease, and the temperature of the laser chip is recorded as Toff. Generally, there is a temperature drift coefficient between the temperature of the laser chip and the working wavelength. This coefficient varies with different types of laser chips, but it is generally between 0.1 and 0.15nm / ℃, that is, for every degree increase or decrease, the emission wavelength will drift by 0.1 to 0.15nm. Therefore, every time the laser chip is turned on, it emits light and generates heat. The temperature of the laser chip starts to rise from Toff and then remains stable to reach Ton. During this process, the temperature of the laser chip changes dramatically and the emission wavelength of the laser chip also drifts.

[0004] As the bandwidth of optical communication expands, more and more wavelengths are multiplexed in the optical communication network, and the wavelength interval between channels is getting smaller and smaller. Therefore, if the temperature difference of the laser chip from Toff to Ton is large enough, its emission wavelength will drift to the adjacent channel, causing the receiving end to lose the optical signal or receive the wrong optical signal. Summary of the invention

[0005] The present application provides an optical module to solve the problem of serious wavelength drift of optical signals emitted by existing optical modules in burst mode.

[0006] The optical module provided in the embodiment of the present application mainly includes:

[0007] Circuit boards;

[0008] A laser chip, electrically connected to the circuit board, comprising a first laser diode and a second laser diode located on the same substrate, wherein the resonant cavity of the second laser diode is arranged non-parallel to the resonant cavity of the first laser diode;

[0009] a driving circuit, arranged on the circuit board, electrically connected to the first laser diode and the second laser diode through the circuit board, respectively, for driving the first laser diode to emit light; and for driving the second laser diode to emit light when the first laser diode is turned off;

[0010] The coupling lens is arranged on the light-emitting side of the first laser diode and is used for collimating the light emitted by the first laser diode.

[0011] The optical module of the embodiment of the present application is provided with a first laser diode and a second laser diode located on the same substrate, and a driving circuit is provided to be electrically connected to the first laser diode and the second laser diode respectively. The driving circuit is provided to drive the first laser diode to emit light, and the first laser diode is stopped from being driven to emit light and the second laser diode is driven to emit light. In this way, when the first laser diode is turned off, the second laser diode is turned on, and the second laser diode and the first laser diode are grown on a laser chip. At this time, the second laser diode can transfer the heat generated when it is turned on to the first laser diode to stabilize the temperature of the first laser diode, reduce the temperature difference between the temperature of the first laser diode between the on and off, and the temperature drift caused by the temperature difference caused by the temperature difference; at the same time, since the resonant cavity of the second laser diode is provided with an angle with the resonant cavity of the first laser diode, the light emitted by the second laser diode can be prevented from entering the coupling lens, thereby avoiding the problem that the shutdown power of the entire optical module does not meet the standard during the shutdown of the first laser diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0013] Figure 1 It is a schematic diagram of the connection relationship of optical communication terminals;

[0014] Figure 2 is a schematic diagram of the structure of an optical network unit;

[0015] Figure 3 This is a schematic diagram of the structure of an optical module provided in this embodiment;

[0016] Figure 4 This is a schematic diagram of the exploded structure of an optical module provided in this embodiment;

[0017] Figure 5 A schematic diagram of the partial structure of the first optical module provided in this embodiment;

[0018] Figure 6 A schematic diagram of the structure of a laser chip provided in this embodiment;

[0019] Figure 7 A schematic diagram of the positional relationship between the laser chip and the coupling lens provided in this embodiment;

[0020] Figure 8 A timing diagram of a burst signal provided in this embodiment;

[0021] Fig. 9 A schematic diagram of a partial structure of a second optical module provided in this embodiment;

[0022] Fig.10 A schematic diagram of the partial structure of the third optical module provided in this embodiment;

[0023] Fig.11 A schematic diagram of the partial structure of the fourth optical module provided in this embodiment;

[0024] Fig.12 A schematic diagram of the partial structure of the fifth optical module provided in this embodiment;

[0025] Fig.13 A schematic diagram of the partial structure of the sixth optical module provided in this embodiment. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in this embodiment to clearly and completely describe the technical solution in this embodiment. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] One of the core links of fiber-optic communication is the conversion of photoelectric signals. Fiber-optic communication uses optical signals carrying information to transmit in optical fibers / waveguides. The passive transmission characteristics of light in optical fibers can achieve low-cost and low-loss information transmission. Computers and other information processing devices use electrical signals, which requires the mutual conversion of electrical signals and optical signals during signal transmission.

[0028] Optical modules realize the above-mentioned photoelectric conversion function in the field of optical fiber communication technology. The mutual conversion between optical signals and electrical signals is the core function of optical modules. Optical modules realize electrical connection with external host computers through gold fingers on the circuit board. The main electrical connections include power supply, I2C signal, transmission data signal and grounding. The electrical connection method realized by gold fingers has become the standard method in the optical module industry. Based on this, circuit boards are an essential technical feature in most optical modules.

[0029] Figure 1 Figure 1 is a schematic diagram of the connection relationship of optical communication terminals. Figure 1 As shown, the connection of the optical communication terminal mainly includes an optical network unit 100, an optical module 200, an optical fiber 101 and a network cable 103;

[0030] One end of the optical fiber is connected to the remote server, and one end of the network cable is connected to the local information processing device. The connection between the local information processing device and the remote server is completed by the connection between the optical fiber and the network cable; and the connection between the optical fiber and the network cable is completed by an optical network unit with an optical module.

[0031] The optical port of the optical module 200 is connected to the optical fiber 101, and a bidirectional optical signal connection is established with the optical fiber; the electrical port of the optical module 200 is connected to the optical network unit 100, and a bidirectional electrical signal connection is established with the optical network unit; the optical module realizes the mutual conversion between optical signals and electrical signals, thereby realizing the establishment of a connection between the optical fiber and the optical network unit; specifically, the optical signal from the optical fiber is converted into an electrical signal by the optical module and then input into the optical network unit 100, and the electrical signal from the optical network unit 100 is converted into an optical signal by the optical module and input into the optical fiber. The optical module 200 is a tool for realizing the mutual conversion of optical and electrical signals, and does not have the function of processing data. In the above-mentioned optical-electrical conversion process, the information does not change.

[0032] The optical network unit has an optical module interface 102, which is used to access the optical module and establish a bidirectional electrical signal connection with the optical module; the optical network unit has a network cable interface 104, which is used to access the network cable and establish a bidirectional electrical signal connection with the network cable; a connection is established between the optical module and the network cable through the optical network unit. Specifically, the optical network unit transmits the signal from the optical module to the network cable, and transmits the signal from the network cable to the optical module. The optical network unit acts as a host computer of the optical module to monitor the operation of the optical module.

[0033] At this point, the remote server establishes a two-way signal transmission channel with the local information processing device through optical fibers, optical modules, optical network units and network cables.

[0034] Common information processing equipment includes routers, switches, and electronic computers. The optical network unit is the host computer of the optical module, which provides data signals to the optical module and receives data signals from the optical module. Other common optical module host computers include optical line terminals.

[0035] Figure 2 Figure 1 is a schematic diagram of the structure of an optical network unit. Figure 2 As shown, a circuit board 105 is provided in the optical network unit 100, and a cage 106 is arranged on the surface of the circuit board 105; an electrical connector is arranged in the cage 106 for accessing the electrical port of the optical module such as the gold finger; a heat sink 107 is arranged on the cage 106, and the heat sink 107 has a protruding structure such as fins for increasing the heat dissipation area.

[0036] The optical module 200 is inserted into the optical network unit. Specifically, the electrical port of the optical module is inserted into the electrical connector in the cage 106 , and the optical port of the optical module is connected to the optical fiber 101 .

[0037] The cage 106 is located on the circuit board, and wraps the electrical connector on the circuit board in the cage; the optical module is inserted into the cage, and the cage fixes the optical module. The heat generated by the optical module is conducted to the cage through the optical module housing, and finally diffused through the heat sink 107 on the cage.

[0038] Figure 3 A schematic diagram of the structure of an optical module 200 provided in an embodiment of the present application is shown in FIG. Figure 4 The present embodiment provides a schematic diagram of the exploded structure of the optical module 200. Figure 3 and Figure 4 As shown, the optical module 200 provided in the embodiment of the present application includes an upper housing 201 , a lower housing 202 , an unlocking handle 203 , a circuit board 204 , a light emitting component 205 and a light receiving component 206 .

[0039] The upper shell 201 is covered on the lower shell 202 to form a wrapping cavity with two openings; the outer contour of the wrapping cavity is generally a square body. Specifically, the lower shell includes a main board and two side panels located on both sides of the main board and perpendicular to the main board; the upper shell includes a cover plate, which is covered on the two side panels of the upper shell to form a wrapping cavity; the upper shell may also include two side walls located on both sides of the cover plate and perpendicular to the cover plate, and the two side walls are combined with the two side panels to achieve the upper shell covering the lower shell.

[0040] The two openings can specifically be two end openings (208, 209) in the same direction, or two openings in different directions; one of the openings is an electrical port 208, and the gold finger of the circuit board extends from the electrical port 208 and is inserted into a host computer such as an optical network unit; the other opening is an optical port 209, which is used for external optical fiber access to connect the optical transmitting component 205 and the optical receiving component 206 inside the optical module; optoelectronic devices such as the circuit board 204, the optical transmitting component 205 and the optical receiving component 206 are located in the encapsulating cavity.

[0041] The upper shell and the lower shell are combined to facilitate installation of components such as the circuit board 204, the optical transmitting component 205 and the optical receiving component 206 into the shell. The upper shell and the lower shell form the outermost packaging protection shell of the optical module. The upper shell and the lower shell are generally made of metal materials, which is conducive to electromagnetic shielding and heat dissipation. The shell of the optical module is generally not made into an integrated structure. In this way, when assembling components such as circuit boards, positioning components, heat dissipation and electromagnetic shielding structures cannot be installed, which is not conducive to production automation.

[0042] The unlocking handle 203 is located on the outer wall of the cavity / lower shell 202 and is used to achieve a fixed connection between the optical module and the host computer, or to release the fixed connection between the optical module and the host computer.

[0043] The unlocking handle 203 has a snap-fit ​​structure that matches the cage of the host computer; pulling the end of the unlocking handle can make the unlocking handle move relative to the surface of the outer wall; the optical module is inserted into the cage of the host computer, and the snap-fit ​​structure of the unlocking handle fixes the optical module in the cage of the host computer; by pulling the unlocking handle, the snap-fit ​​structure of the unlocking handle moves accordingly, thereby changing the connection relationship between the snap-fit ​​structure and the host computer, so as to release the snap-fit ​​relationship between the optical module and the host computer, so that the optical module can be pulled out of the cage of the host computer.

[0044] The circuit board 204 is provided with circuit traces, electronic components (such as capacitors, resistors, transistors, MOS tubes) and chips (such as microprocessor MCU2045, laser driver chip, limiting amplifier, clock data recovery CDR, power management chip, data processing chip DSP) and the like.

[0045] The circuit board 204 connects the electrical components in the optical module together according to the circuit design through circuit routing to achieve electrical functions such as power supply, electrical signal transmission and grounding.

[0046] The circuit board 204 is generally a rigid circuit board. Due to its relatively hard material, the rigid circuit board can also realize the load-bearing function. For example, the rigid circuit board can stably carry the chip; when the optical transmitting component 205 and the optical receiving component 206 are located on the circuit board, the rigid circuit board can also provide stable load-bearing; the rigid circuit board can also be inserted into the electrical connector in the upper computer cage. Specifically, a metal pin / gold finger is formed on the end surface of one side of the rigid circuit board for connecting to the electrical connector; these are not easy to achieve with flexible circuit boards.

[0047] Flexible circuit boards are also used in some optical modules as a supplement to rigid circuit boards. Flexible circuit boards are generally used in conjunction with rigid circuit boards. For example, flexible circuit boards can be used to connect rigid circuit boards to optical transceiver devices.

[0048] The optical transmitting component 205 and the optical receiving component 206 are used to transmit and receive optical signals, respectively. The optical transmitting component 206 in this embodiment adopts a coaxial TO package, is physically separated from the circuit board, and is electrically connected through a flexible board; the optical receiving component 206 also adopts a coaxial TO package, is physically separated from the circuit board, and is electrically connected through a flexible board. In another common implementation method, it can be set on the surface of the circuit board 204; in addition, the optical transmitting component 205 and the optical receiving component 206 can also be combined together to form an integrated optical transceiver structure.

[0049] Furthermore, the gold finger on the surface of the circuit board 204 has an I2C pin, and the upper computer and the optical module can use the I2C protocol to transmit information through the I2C pin. Among them, for the signal transmission of the optical module, the burst signal from the upper computer passes through the input of the gold finger on the surface of the circuit board 204 and enters the laser driver chip Driver. The laser driver chip Driver adjusts the amplitude of the burst signal and outputs it to the optical transmission component 205 to drive the laser chip in the optical transmission component 205 to emit light of a preset wavelength. However, in the above-mentioned burst mode, the laser chip in the optical transmission component 205 is constantly turned on and off, which will cause the wavelength of its light output to change due to the change of chip temperature. In addition, with the expansion of optical communication bandwidth, more and more wavelengths are reused in the optical communication network, the interval between wavelengths is getting smaller and smaller, and the rate of optical signals is getting higher and higher. Therefore, the actual wavelength of the light emitted by the laser chip will be confused with the preset communication channel, causing the receiving end to lose the optical signal or receive the wrong optical signal.

[0050] In view of the above problems, this embodiment designs a new optical module solution. Figure 5 This is a partial structural diagram of the first optical module provided in this embodiment. In actual products, there are many packaging methods used in optical modules, such as TO packaging, COB packaging, BOX packaging and silicon-based optical chip packaging. The specific structure will change adaptively when using specific packaging, but its essential principle is as follows: Figure 5 In this embodiment, a driving circuit 10 is provided in the optical module, and a laser chip 20 including a first laser diode 21 and a second laser diode 22 is provided in the optical emission component.

[0051] Figure 6 This is a schematic diagram of the structure of a laser chip provided in this embodiment. Figure 6As shown, two active regions Wa and Wb are arranged on the substrate 23 of the laser chip 20, and an isolation groove 24 is arranged between the active regions Wa and Wb. The isolation groove 24 divides the laser chip into two light-emitting units. In this embodiment, the two independent light-emitting units are respectively formed into a first laser diode 21 and a second laser diode 22. In addition, the resonant cavity of the first laser diode 21 and the resonant cavity of the second laser diode 22 are arranged non-parallel, that is, the two have a certain angle, so in Figure 6 In the cross-sectional view of the laser chip in FIG. 1 , the widths of the active regions of the first laser diode 21 and the second laser diode 22 are different.

[0052] The driving circuit 10 is disposed on the circuit board 204 and is electrically connected to the anodes of the first laser diode 21 and the second laser diode 22 through the wiring on the circuit board 204. In addition, the cathodes of the first laser diode 21 and the second laser diode 22 are mounted on a TEC (thermoelectric cooler) and grounded, and can also be directly grounded.

[0053] A double-pole double-throw switch is provided in the driving circuit 10, and the double-pole double-throw switch is controlled by a burst signal. One end of the double-pole double-throw switch is electrically connected to the anodes of the first laser diode 21 and the second laser diode 22, respectively, and the other end is movably connected to contacts A, A', B, and B', respectively, wherein contacts A and B' are grounded, contacts A' and B are connected to a current source, contacts A and B can be conducted with the first laser diode 21, and contacts A' and B' can be conducted with the second laser diode 22.

[0054] Figure 8 A timing diagram of a burst signal provided in this embodiment. Figure 8 As shown, the burst signal is a rectangular wave signal whose voltage changes with time. At t1, it changes from a low level to a high level; at t2, it changes from a high level to a low level; at t3, it changes from a low level to a high level, and so on. The burst signal is generally generated by the host computer, and the time for which the high level or low level is maintained is set by the actual light emission needs. In this embodiment, when the burst signal is at the first level, the drive circuit drives the first laser diode 21 to work; when the burst signal is at the second level, the first laser diode 21 is stopped from driving to work, and the second laser diode 22 is driven to work. The burst signal is a signal in which the first level and the second level change with each other, which is specifically embodied as a signal of high and low level changes. Specifically, when the optical signal needs to be transmitted, a high level signal is provided to the drive circuit 10; when the optical signal does not need to be transmitted, a low level signal is provided to the drive circuit 10. Of course, it is also possible to provide a low level signal to the drive circuit 10 when the optical signal needs to be transmitted; and to provide a high level signal to the drive circuit 10 when the optical signal does not need to be transmitted.

[0055] Based on the timing change of the above-mentioned burst signal. When the burst signal is at the first level, the double-pole double-throw switch is enabled to be turned on with B and B', at this time, the anode of the first laser diode 21 is connected to the bias current and then emits light, and the anode of the second laser diode 22 is grounded and cannot emit light. When the burst signal is at the second level, the double-pole double-throw switch is enabled to be turned on with A and A', the anode of the first laser diode 21 is grounded, and the anode of the second laser diode 22 is connected to the bias current. At this time, the second laser diode 22 can obtain current and emit light normally, and the first laser diode 21 does not emit light because it does not obtain current; when coupling the laser light, we select the first laser diode 21 as the working diode, so that the light emitted by the first laser diode 21 is aligned with the coupling lens 30, and then the light it emits is coupled into the optical fiber. The second laser diode 22 is a heating diode. Since there is an angle between the resonant cavity of the second laser diode 22 and the resonant cavity of the first laser diode 21, it can effectively reduce the light emitted by the second laser diode 22 from being coupled into the optical fiber through the coupling lens 30.

[0056] Figure 7 Schematic diagram of the positional relationship between the laser chip and the coupling lens provided in this embodiment. Figure 7 As shown, in order to avoid the light emitted by the second laser diode 22 from being coupled into the optical fiber through the coupling lens 30 as much as possible, the light-emitting point of the first laser diode 21 is arranged in the present embodiment to be located near the focal point F of the coupling lens 30, and the angle θ between the resonant cavity of the second laser diode 22 and the resonant cavity of the first laser diode 21 is arranged to be greater than the angle μ between the central axis of the coupling lens 30 and the maximum angle ray, wherein the maximum incident angle ray μ is defined as the ray parallel to the line connecting the focal point F of the coupling lens 30 and the edge of the coupling lens 30 in the present embodiment. In addition, a light-absorbing component may be arranged in the light-emitting direction of the second laser diode 22 to absorb the light emitted by the second laser diode 22, wherein the light-absorbing component may be arranged on the light-emitting cavity surface of the second laser diode 22, or mounted on the inner wall of the TO tube used to encapsulate the first laser diode 21 and the second laser diode 22.

[0057] In this embodiment, two laser diodes are designed at the chip level. Combined with the strong consistency of the existing chip manufacturing process, the thermal efficiency of the two laser diodes when working is very close. Moreover, they are grown on the same substrate, and the efficiency of heat exchange of the two laser diodes is very high. Moreover, by configuring the driving circuit, no matter whether the first laser diode 21 or the second laser diode 22 is working, only one of the two laser diodes is working at the same time, so the heat generated by the entire laser chip changes very little, and the wavelength changes very little, which can meet the demanding wavelength division multiplexing technical requirements. At the same time, since there is an angle between the resonant cavity of the second laser diode 22 and the resonant cavity of the first laser diode 21, the light emitted by the second laser diode 22 can be prevented from entering the coupling lens, thereby avoiding the problem that the shutdown power of the entire optical module does not meet the standard during the shutdown period of the first laser diode 21.

[0058] Furthermore, the driving circuit 10 in this embodiment may also adopt other circuit structures, and specific embodiments will be given below.

[0059] Fig. 9 The schematic diagram of the partial structure of the second optical module provided in this embodiment. Fig. 9 In the optical module provided in this embodiment, the driving circuit 10 includes a first driving circuit 11 and a second driving circuit 12, the first driving circuit 11 is connected to the first laser diode 21, and the second driving circuit 12 is connected to the second laser diode 22, wherein the first driving circuit 11 is used to make the first laser diode 21 emit light of the working wavelength when the received burst signal is a first level value; and is used to make the first laser diode 21 stop emitting light, i.e., turn it off, when the received burst signal is a second level value; the second driving circuit 12 is used to make the second laser diode 22 emit light when the received burst signal is a second level value.

[0060] Specifically, the first drive circuit 11 can use an existing laser drive chip. For example, in one embodiment, the anode of the first laser diode 21 is connected to a current source that can output a preset current signal, and the cathode of the first laser diode 21 is connected to the first drive circuit 11. At this time, when the first drive circuit 11 receives a burst signal of the first level, the port connected to the first laser diode 21 is set to a low level, so that there is a voltage difference between the two ends of the first laser diode 21, and the first laser diode 21 is turned on and emits light of the working wavelength. Further, when the first drive circuit 11 receives a burst signal of the second level, the port connected to the first laser diode 21 is set to a high level, for example, the port connected to the first laser diode is set to a voltage of the same value as the output port of the current source, and at this time, there is no voltage difference between the two ends of the first laser diode 21, and the first laser diode 21 is turned off.

[0061] Furthermore, the second driving circuit 12 may adopt an existing laser driving chip or other circuit structures. A specific embodiment will be given below to introduce the circuit structure of the second driving circuit 12 in detail, which will not be repeated here.

[0062] Fig.10 The schematic diagram of the partial structure of the third optical module provided in this embodiment. Fig.10 As described above, based on the second optical module, in the optical module provided in this embodiment, the second driving circuit 12 includes a first electric switch 121 , a first MOS tube 122 and a first operational amplifier 123 .

[0063] The input end of the first operational amplifier 123 is connected to the MCU of the optical module, the output end of the first operational amplifier 123 is connected to the gate G of the first MOS tube 122, the drain D of the first MOS tube 122 is connected to the cathode of the second laser diode, and the source S of the first MOS tube 122 is connected to the first end of the first electric switch 121. The second end of the first electric switch 121 can be grounded through a resistor. At the same time, the first electric switch 121 is closed when the received burst signal is the second level value, so that the second laser diode 22 is turned on.

[0064] In addition, the specific structure of the first operational amplifier 123 can refer to the description in the prior art, which will not be repeated here. Further, the first operational amplifier 123 can be an operational amplifier with a fixed amplification factor, or an operational amplifier with an adjustable amplification factor. When the first operational amplifier 123 is an operational amplifier with an adjustable amplification factor, the amplification factor of the first operational amplifier 123 can be adjusted according to actual needs. For example, in order to minimize the temperature drift of the first laser diode 21, the amplification factor of the first operational amplifier 123 is adjusted to 1.

[0065] Further, the input end of the first operational amplifier 123 is connected to the MCU of the optical module, and the MCU is used to provide an input voltage to the first operational amplifier 123. Specifically, the MCU can determine the specific value of the input voltage provided to the first operational amplifier 123 according to the feedback data (for example, the feedback data can include the bias current or the wavelength of the light emitted by the first laser diode 21) to control the magnitude of the current flowing through the second laser diode 22. For example, in one embodiment, the specific value of the input voltage provided to the first operational amplifier 123 can be determined according to the current flowing through the first laser diode 21 when the first laser diode 21 emits an optical signal, so as to control the current flowing through the second laser diode 22, thereby reducing the temperature difference of the first laser diode 21 from the shutdown process to the conduction process to 0. For example, in one embodiment, when the first laser diode 21 is turned on, the current flowing through the first laser diode 21 is i1. At the same time, when the first laser diode 21 is turned on, the second laser diode 22 is not turned on. At this time, in order to reduce the temperature drift of the first laser diode 21, i12*r1*6.25=i22*r2*118.75 can be set (wherein, i2 is the current flowing through the second laser diode 22 when the second laser diode 22 is turned on; r1 is the internal resistance of the first laser diode 21; r2 is the internal resistance of the second laser diode 22; 6.25us is the time when the first laser diode 21 is turned on during a burst signal cycle; 118.75us is the time when the first laser diode 21 is turned off during a burst signal cycle). In this way, i2 can be calculated through i1, and then the specific value of the input voltage provided by the MCU to the first operational amplifier 123 can be determined according to i2 and the current amplification factor of the first operational amplifier 123 (for example, the specific value of the input voltage provided by the MCU to the first operational amplifier 123 is determined to be aV). In this way, when the MCU provides an input voltage of aV to the first operational amplifier 123, when the second laser diode 22 is turned on, the current flowing through the second laser diode 22 is i2.

[0066] The optical module provided in this embodiment sets the second driving circuit as a circuit including a first operational amplifier, a first MOS tube and a first electric switch. Thus, when the second laser diode is turned on, the current flowing through the second laser diode can be controlled by the MCU to control the heat emitted by the second laser diode, thereby reducing the temperature difference of the first laser diode from the shutdown process to the conduction process to 0, so as to reduce the temperature drift of the optical signal emitted by the first laser diode caused by the temperature drift of the first laser diode.

[0067] Fig.11 The schematic diagram of the partial structure of the fourth optical module provided in this embodiment. Fig.11In the optical module provided in this embodiment, the anode of the first laser diode 21 is connected to the current source, and the cathode of the first laser diode 21 is connected to the first drive circuit 11; the anode of the second laser diode 22 is connected to the second drive circuit 12, and the cathode of the second laser diode 22 is grounded; wherein the second drive circuit 12 is used to output current to the second laser diode 22 when receiving the above-mentioned burst signal with a second level value, so as to turn on the second laser diode 22.

[0068] The anode of the first laser diode 21 can be connected to a current source through a resistor, and the current source can be a 3.3V current source. In addition, the first drive circuit 11 can use an existing laser drive chip. In this case, it is only necessary to connect a bias current port of the drive chip to the cathode of the first laser diode 21.

[0069] It should be noted that, in this embodiment, the magnitude of the current output by the second drive circuit 12 can be controlled by the controller in the optical module. The controller can specifically be an MCU originally integrated in the optical module. In addition, the controller can also be an FPGA or a CPU, etc. For example, in one embodiment, the magnitude of the current output by the second drive circuit 12 can be adjusted according to the current flowing through the first laser diode 21 when the first laser diode 21 emits light, so as to adjust the heat emitted when the second laser diode 22 is turned on, thereby reducing the temperature difference of the first laser diode 21 from the shutdown process to the conduction process to 0. The specific implementation principle of adjusting the current output by the second drive circuit 12 according to the current flowing through the first laser diode 21 when the first laser diode 21 is turned on can be referred to the description of the previous embodiment, which will not be repeated here.

[0070] Fig.12 The schematic diagram of the partial structure of the fifth optical module provided in this embodiment. Fig.12 As shown, in the optical module provided in this embodiment, the second driving circuit 12 includes a second operational amplifier 124 , a second MOS transistor 125 and a second electric switch 126 .

[0071] The input end of the second operational amplifier 124 is connected to the MCU of the optical module, the output end of the second operational amplifier 124 is connected to the gate G of the second MOS tube 125, the source S of the second MOS tube 125 is connected to the current source, the drain D of the second MOS tube 125 is connected to the first end of the second electric switch 126, the second end of the second electric switch 126 is connected to the anode of the second laser diode 22, and the cathode of the second laser diode 22 is grounded.

[0072] The second electric switch 126 is used to connect the second MOS transistor 125 to the second laser diode 22 when the burst signal received is of a second level value.

[0073] In addition, the second operational amplifier 124 can be an operational amplifier with a fixed amplification factor or an operational amplifier with an adjustable amplification factor. When the second operational amplifier 124 is an operational amplifier with an adjustable amplification factor, the amplification factor of the second operational amplifier 124 can be adjusted according to actual needs. For example, in order to control the heat emitted by the second laser diode 22 when the second laser diode 22 is turned on, the amplification factor of the second operational amplifier 124 is adjusted to 2. Further, the input end of the second operational amplifier 124 is connected to the MCU of the optical module, and the MCU is used to provide an input voltage to the second operational amplifier 124. Specifically, the MCU can control the current flowing through the second laser diode 22 according to the feedback data (for example, the feedback data can be a bias current or the wavelength of the light emitted by the first laser diode 21), thereby reducing the temperature difference of the first laser diode 21 from the shutdown process to the conduction process to 0. In order to reduce the wavelength drift of the optical signal emitted by the first laser diode 21 due to the temperature drift of the first laser diode 21.

[0074] Optionally, in a possible implementation of the present application, the second electrical switch 126 is a single-pole single-throw electrical switch; the second electrical switch 126 is used to close when receiving the burst signal with a second level value, so that the second MOS tube 125 outputs current to the second laser diode 22. Further, in another possible implementation of the present application, the second electrical switch 126 is a switching switch.

[0075] Fig.13 The sixth optical module provided in this embodiment is a partial structural diagram. Fig.13 As shown, the second driving circuit 12 also includes a first resistor 127, a third end of the second electric switch 126 is connected to the first end of the first resistor 127, and the second end of the first resistor 127 is grounded; the second electric switch 126 is used to connect the second MOS tube 125 to the first resistor 127 when the above-mentioned burst signal is received as a first level value.

[0076] Specifically, the optical module provided in this embodiment sets the second electric switch 126 as a switching switch. In this way, when the burst signal received is a first level value, the first end of the second electric switch 126 is connected to the third end, at which time the second laser diode 22 is not turned on and the first resistor 127 is turned on. Further, when the burst signal received is a second level value, the first end of the second electric switch 126 is connected to the second end, at which time the second laser diode 22 is turned on. It should be noted that in this embodiment, although the first resistor 127 is turned on when the first laser diode 21 is turned on, the first resistor 127 is not thermally coupled with the first laser diode 21. Therefore, although the first resistor 127 generates heat when the first laser diode 21 is turned on, it will not transfer the generated heat to the first laser diode 21.

[0077] The optical module provided in this embodiment configures the second driving circuit to be a circuit including a second operational amplifier, a second MOS tube and a second electric switch. Thus, the current flowing through the second laser diode when the second laser diode is turned on can be controlled by controlling the input voltage or amplification factor of the second operational amplifier, so as to minimize the temperature drift of the first laser diode and reduce the wavelength drift of the optical signal emitted by the first laser diode caused by the temperature drift of the first laser diode.

[0078] It should be noted that the optical module provided in this embodiment is not only applicable to the form of packaging the above-mentioned optical transmitting component and optical receiving component separately, but also applicable to packaging forms such as packaging the optical transmitting component and the optical receiving component together to form an optical transceiver submodule, mounting the optical transceiver chip on a circuit board, etc., and for any packaging form, the related devices for sending optical signals are referred to as optical transmitting components in this embodiment, and the related devices for receiving optical signals are referred to as optical receiving components in this embodiment. In addition, the above-mentioned optical module can be an optical module in an OLT or an ONU, but is not limited thereto.

[0079] Finally, it should be noted that: this embodiment is described in a progressive manner, and different parts can refer to each other; in addition, the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that: it is still possible to modify the technical solutions recorded in the aforementioned embodiments, or to replace some of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An optical module, characterized in that: include: Circuit boards; A laser chip, electrically connected to the circuit board, comprising a first laser diode and a second laser diode located on the same substrate, wherein the resonant cavity of the second laser diode is arranged non-parallel to the resonant cavity of the first laser diode, and the angle between the resonant cavity of the second laser diode and the resonant cavity of the first laser diode is greater than the angle between the central axis of the coupling lens and the maximum angle ray, and the maximum angle ray is a ray parallel to the line connecting the focus and the edge of the coupling lens; a light absorbing component is arranged in the light emitting direction of the second laser diode; a driving circuit, arranged on the circuit board, electrically connected to the first laser diode and the second laser diode through the circuit board, respectively, for driving the first laser diode to emit light; and for driving the second laser diode to emit light when the first laser diode is turned off; The coupling lens is arranged on the light-emitting side of the first laser diode and is used for collimating the light emitted by the first laser diode.

2. The optical module according to claim 1, characterized in that: The light emitting point of the first laser diode is located near the focus of the coupling lens.

3. The optical module according to claim 1, characterized in that: The driving circuit comprises a switching switch, wherein: The first end of the switch is connected to the current source, the second end of the switch is connected to the anode of the first laser diode, and the third end of the switch is connected to the anode of the second laser diode; The switching switch is used to connect the current source to the first laser diode when the received burst signal is a first level value so that the first laser diode emits light; and to connect the current source to the second laser diode when the received burst signal is a second level value so that the first laser diode is turned off and the second laser diode emits light.

4. The optical module according to claim 1, characterized in that: The driving circuit comprises a first driving circuit and a second driving circuit, wherein: The first driving circuit is connected to the first laser diode, and is used to make the first laser diode emit light when the received burst signal has a first level value; and is used to make the first laser diode stop emitting light when the received burst signal has a second level value; The second driving circuit is connected to the second laser diode, and is used to make the second laser diode emit light when the received burst signal has a second level value.

5. The optical module according to claim 4, characterized in that: The second drive circuit comprises a first electrical switch, wherein: The anode of the first laser diode and the anode of the second laser diode are respectively connected to a current source, and the cathode of the first laser diode is connected to the first driving circuit; The cathode of the second laser diode is connected to the first end of the first electric switch, and the second end of the first electric switch is grounded; The first electrical switch is used to close when the received burst signal has a second level value, so as to enable the second laser diode to emit light.

6. The optical module according to claim 5, characterized in that: The second driving circuit further includes a first operational amplifier and a first MOS tube, wherein: The input end of the first operational amplifier is connected to the MCU of the optical module, the output end of the first operational amplifier is connected to the gate of the first MOS tube, the drain of the first MOS tube is connected to the cathode of the second laser diode, and the source of the first MOS tube is connected to the first end of the first electric switch.

7. The optical module according to claim 4, characterized in that: The anode of the second laser diode is connected to the second driving circuit, and the cathode of the second laser diode is grounded; The second driving circuit is used to output current to the second laser diode when the received burst signal has a second level value, so as to make the second laser diode emit light.

8. The optical module according to claim 7, characterized in that: The second driving circuit includes a current source, a second operational amplifier, a second MOS tube and a second electric switch, wherein: The input end of the second operational amplifier is connected to the MCU of the optical module, the output end of the second operational amplifier is connected to the gate of the second MOS tube, the source of the second MOS tube is connected to the output end of the current source, the drain of the second MOS tube is connected to the first end of the second electric switch, the second end of the second electric switch is connected to the anode of the second laser diode, and the cathode of the second laser diode is grounded; The second electric switch connects the second MOS transistor to the second laser diode when the received burst signal has a second level value.

9. The optical module according to claim 8, characterized in that: The second electrical switch is a switching switch, and the second driving circuit further includes a first resistor, wherein: The third end of the second electrical switch is connected to the first end of the first resistor, and the second end of the first resistor is grounded; The second electrical switch is used to connect the second MOS transistor to the first resistor when the received burst signal has a first level value.

Images