Integrated laser driving circuit for OTDR (Optical Time Domain Reflectometer) optical module and optical module

Abstract

The utility model discloses an integrated laser drive circuit for an OTDR optical module and the optical module. The integrated laser drive circuit comprises a laser chip, a laser drive chip, a pulse generation circuit and a microcontroller. The laser driving chip comprises n paths of high-speed communication driving channels and n paths of OTDR driving channels which are correspondingly connected with the n paths of lasers in the laser chip respectively so as to realize time division multiplexing of the n paths of lasers. And the microcontroller controls the laser driving chip to gate and switch between the high-speed communication driving channel and the OTDR driving channel through a register arranged in the laser driving chip, and controls the pulse generation circuit to transmit a pulse signal for OTDR testing to the laser driving chip. According to the optical module, a high-speed switching chip does not need to be used, switching between a high-speed communication function and a network diagnosis function is achieved through cooperation of the microcontroller and the built-in register of the laser driving chip, the circuit integration degree is high, and miniaturization packaging of the optical module is facilitated.

Description

Technical Field

[0001] This utility model belongs to the field of optical fiber communication technology and relates to an optical module, specifically, to an integrated laser driver circuit for an OTDR optical module. Background Technology

[0002] Optical Time Domain Reflectometry (OTDR) is one of the most effective methods for detecting fiber length, fiber attenuation, splice loss, and fault location, and is widely used in the construction and maintenance of optical cable lines. When a fiber optic link requires maintenance or experiences a fault, maintenance personnel must carry an OTDR to disconnect the fiber optic network on-site to perform maintenance and diagnosis, and then troubleshoot and repair the problem. This process is extremely costly.

[0003] To enable online testing of fiber optic networks, optical modules integrating OTDR functionality have emerged. Compared to OTDR test instruments, these modules are relatively small in size, integrating OTDR and high-speed communication functions. Testing does not require disconnecting the fiber optic network, simplifying operation and reducing network maintenance costs. However, these OTDR optical modules can only be used in a single fiber optic channel and require specially designed driver circuits, necessitating an external optical module, thus resulting in a relatively low level of integration.

[0004] In data center communications and specialized optical network applications, optical cables contain a large number of optical fibers, requiring the simultaneous transmission of multiple communication optical signals. The optical modules used are multi-channel parallel transmission optical modules. These multi-channel optical modules have small package sizes and high communication signal transmission rates. The driving circuits designed for these modules are dedicated multi-channel parallel chips, which integrate multiple independently operating laser driving circuits.

[0005] To integrate OTDR testing functionality within a multi-channel optical module, existing methods such as Figure 1 As shown, the high-speed communication signal is driven by a laser driver chip, which is a multi-channel chip array. The OTDR pulse signal driver does not yet have a multi-channel chip array and is implemented using discrete circuitry, including a multi-channel pulse generation circuit and a multi-channel OTDR driver circuit. The pulse generation circuit generates narrow pulse electrical signals, and the OTDR driver circuit loads these narrow pulse electrical signals onto the laser chip. A high-speed switching chip is used to select and switch between the high-speed communication signal and the narrow pulse electrical signal, enabling multiplexing of the two signals onto the laser chip. The high-speed switching chip is controlled by a microcontroller.

[0006] The main problems with the above solution are as follows:

[0007] (1) Selecting a high-speed switching chip to switch between two functions requires that the bandwidth of the high-speed switching chip be greater than that of the high-speed communication function. For a high-speed communication signal with a communication rate of 10Gbps, the bandwidth of the high-speed switching chip needs to be greater than 8GHz. However, the size and power consumption of such high-speed switching chips are very large, and a dedicated power supply chip is also required to provide voltage. Therefore, it is not conducive to the miniaturization and low power consumption design of optical modules.

[0008] (2) A high-speed switching chip is added between the laser driver chip and the laser chip. In the actual circuit design, the multi-channel laser driver chip is a bare die, the high-speed switching chip is a plastic-encapsulated component, and the laser chip is a bare die. Therefore, the pads of the laser driver chip need to be wire-bonded to the substrate first, and then connected to the input pins of the high-speed switching chip through the internal traces of the substrate. The input and output pins of the high-speed switching chip are soldered to the substrate, reach the laser chip position through the internal traces of the substrate, and then connected to the laser chip through wire bonding. This circuit design causes the high-speed communication signal to have to go through a long path and multiple impedance discontinuities to reach the laser chip. The signal noise is large, the signal quality is easily distorted, and the communication quality and the accuracy of fiber optic network diagnosis are affected.

[0009] (3) The pulse generation circuit and OTDR drive circuit do not have multi-channel chips. They need to be combined with single chips and then designed side by side, which results in large size and power consumption, making integration difficult.

[0010] (4) The microcontroller needs to coordinate the control of the pulse generation circuit, laser driver chip, high-speed switching chip, etc., which is complex and occupies a lot of IO port resources, thus limiting the selection of microcontrollers. Utility Model Content

[0011] In order to solve at least one of the above-mentioned technical problems existing in existing multi-channel OTDR optical modules, this utility model proposes an integrated laser driving circuit for OTDR optical modules. By improving the integration of the driving circuit, the miniaturization design of multi-channel OTDR optical modules can be achieved.

[0012] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0013] In one aspect, this invention proposes an integrated laser driver circuit for an OTDR optical module, comprising:

[0014] A laser chip, which is a laser array with n channels, is used for electro-optical conversion, where n>1;

[0015] A laser driver chip, which is a driver chip array with 2n channels; the laser driver chip includes a high-speed communication driver channel, an OTDR driver channel, and registers; wherein,

[0016] The high-speed communication driving channel has n channels and is used to receive n high-speed communication signals, modulate them, and then drive the n lasers in the laser chip to convert the n high-speed communication signals into n optical signals.

[0017] The OTDR drive channel has n channels. After receiving and modulating the pulse signal used for OTDR testing, it drives the n lasers in the laser chip to convert the n pulse signals into n optical pulses.

[0018] The register is used to receive channel selection instructions; the laser driver chip switches between the high-speed communication driver channel and the OTDR driver channel according to the channel selection instructions written in the register.

[0019] A pulse generation circuit generates pulse signals for OTDR testing and transmits them to the OTDR drive channel;

[0020] The microcontroller generates the channel selection instruction and sends it to the register, and controls the pulse generation circuit to output the pulse signal used for OTDR testing.

[0021] In some embodiments of this application, in order to shorten the wiring length between the laser driver chip and the laser chip, reduce signal noise, and ensure the transmission quality of high-speed communication signals, the n high-speed communication driver channels and n OTDR driver channels can be arranged alternately on the laser driver chip, and an adjacent set of high-speed communication driver channels and OTDR driver channels can be selected to connect to the same laser in the laser chip, so as to realize the multiplexing of high-speed communication signals and OTDR pulse signals to the laser.

[0022] In some embodiments of this application, when the 2n drive channels of the laser driver chip are differential channels, two differential + output terminals of a set of high-speed communication drive channels and OTDR drive channels connected to the same laser can be connected to the anode of the laser, and one differential - output terminal can be connected to the cathode of the laser. The drive current output by the two differential + output terminals is used to drive the laser to emit light, so as to realize the time-division multiplexing of high-speed communication function and OTDR detection function.

[0023] In some embodiments of this application, the laser driver chip and the laser chip can be arranged side by side on the substrate, with the laser chip located on the output side of the drive channel of the laser driver chip. The two chips are connected by gold wire bonding. By minimizing the wiring distance between the two chips, the communication quality of high-speed communication signals can be guaranteed and distortion can be reduced.

[0024] In some embodiments of this application, a ceramic block can be placed between the lower surface of the laser chip and the substrate to achieve insulation between the laser chip and the substrate.

[0025] In some embodiments of this application, an adapter pad may be provided on the ceramic block, and the laser driver chip may be first wire bonded to the adapter pad, and then the laser chip may be connected to the adapter pad by wire bonding.

[0026] In some embodiments of this application, to reduce the package size of the optical module, the laser driver chip can be a bare die, directly bonded to the substrate. To receive high-speed communication signals, the input terminal of the high-speed communication drive channel of the laser driver chip can be connected to the substrate via wire bonding, and the electrical interface of the optical module can be connected via internal traces on the substrate. The electrical interface receives n high-speed communication signals transmitted in parallel from the user side.

[0027] In some embodiments of this application, the microcontroller can be configured to output two pulse signals to the pulse generation circuit, and the pulse signal output by the pulse generation circuit for OTDR testing can be controlled to be a narrow pulse signal in the nanosecond or picosecond range. Then, the laser driver chip and the laser chip output OTDR detection optical pulses with a pulse width in the nanosecond or picosecond range, so that the OTDR optical module of this application can be used for short-distance multimode fiber optic transmission links.

[0028] In some embodiments of this application, NOT gates and AND gates can be set in the pulse generation circuit; wherein, the NOT gate is used to invert one pulse signal output by the microcontroller; the AND gate is used to perform an AND operation on the pulse signal output by the NOT gate and another pulse signal output by the microcontroller to generate an output pulse; the microcontroller is configured to adjust the time difference between the two output pulse signals to change the pulse width of the output pulse generated by the AND gate, thereby generating a narrow pulse signal at the nanosecond or picosecond level.

[0029] In another aspect, this utility model also proposes an optical module, including a housing and an integrated laser driving circuit encapsulated within the housing; the integrated laser driving circuit includes:

[0030] A laser chip, which is a laser array with n channels, is used for electro-optical conversion, where n>1;

[0031] A laser driver chip, which is a driver chip array with 2n channels; the laser driver chip includes a high-speed communication driver channel, an OTDR driver channel, and registers; wherein,

[0032] The high-speed communication driving channel has n channels and is used to receive n high-speed communication signals, modulate them, and then drive the n lasers in the laser chip to convert the n high-speed communication signals into n optical signals.

[0033] The OTDR drive channel has n channels and is used to receive n pulse signals for OTDR testing, modulate them, and drive the n lasers in the laser chip to convert the n pulse signals into n optical pulses.

[0034] The register is used to receive channel selection instructions; the laser driver chip switches between the high-speed communication driver channel and the OTDR driver channel according to the channel selection instructions written in the register.

[0035] A pulse generation circuit generates pulse signals for OTDR testing and transmits them to the OTDR drive channel;

[0036] The microcontroller generates the channel selection instruction and sends it to the register, and controls the pulse generation circuit to output the pulse signal used for OTDR testing.

[0037] Compared with the prior art, the advantages and positive effects of this utility model are mainly reflected in:

[0038] 1. This utility model designs an optical module for multi-channel fiber optic networks, which has multi-channel parallel high-speed communication function and multi-channel parallel fiber optic network detection function. The two functions are multiplexed by a laser driver chip and a laser chip. The microcontroller switches between the two functions by cooperating with the registers inside the laser driver chip. This minimizes the optical path and circuit scheme, improves the system integration, and helps to reduce the package size of the optical module.

[0039] 2. Compared to existing OTDR optical modules, this invention eliminates the need for a high-speed switching chip, resulting in lower system power consumption and eliminating the need for a dedicated power supply chip to power the high-speed switching chip, thereby reducing the complexity of the optical module system circuitry. Furthermore, by eliminating the high-speed switching chip, the laser driver chip and the laser chip can be arranged adjacently and directly connected via gold wire bonding, minimizing the high-speed communication signal transmission lines, reducing signal noise, ensuring signal quality, and avoiding distortion.

[0040] 3. This utility model uses time-division multiplexing technology to isolate the high-speed communication function and the fiber optic network detection function, so that they do not interfere with each other. During testing, the connection status of the multi-channel fiber optic network can be diagnosed without disconnecting the multi-channel fiber optic network, which helps to improve the maintenance efficiency of the multi-channel fiber optic network.

[0041] 4. This utility model designs a pulse generation circuit that works with a microcontroller to generate narrow pulse signals at the nanosecond or picosecond level, which are then transmitted to a laser driver chip to drive the laser chip to emit OTDR detection light pulses at the nanosecond or picosecond level. This can meet the OTDR detection requirements of multi-channel fiber optic networks with fiber optic distances within 300 meters and distances between two event points of tens of centimeters or less.

[0042] 5. The OTDR optical module of this utility model is particularly suitable for installation in fiber optic links in the fields of data center communication and special optical network applications, so as to solve the problems of daily management, maintenance and testing of fiber optic networks in these fields.

[0043] Other features and advantages of this utility model will become clearer after reading the detailed description of the embodiments of this utility model in conjunction with the accompanying drawings. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a block diagram of the laser driver circuit in an existing multi-channel OTDR optical module;

[0046] Figure 2 This is a circuit block diagram of one embodiment of the integrated laser driver circuit for OTDR optical modules proposed in this utility model.

[0047] Figure 3 It is Figure 2 A schematic diagram showing the arrangement and wiring method of a laser driver chip and a laser chip disposed on a substrate in one embodiment.

[0048] Figure 4 It is Figure 2 A schematic diagram showing the arrangement and wiring method of the laser driver chip and the laser chip arranged on the substrate in another embodiment.

[0049] Figure 5 This is a circuit schematic diagram of one embodiment of a pulse generation circuit;

[0050] Figure 6 yes Figure 5 Waveforms of the input and output pulses of the AND gate;

[0051] Figure 7This is a circuit block diagram of one embodiment of the multi-channel OTDR optical module proposed in this utility model. Detailed Implementation

[0052] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0053] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances. In the description of the embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0054] In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0055] To implement OTDR testing functionality on a multi-channel optical module while also meeting the miniaturization requirements of the multi-channel optical module, this embodiment integrates the functions of a high-speed switching chip and an OTDR driving circuit from existing technologies into a conventional multi-channel laser driver chip. This enables time-division modulation of high-speed communication signals and OTDR pulse signals, as well as time-division driving of the laser chip. While improving the system circuit integration, it can shorten the wiring distance between the multi-channel laser driver chip and the laser chip, thereby ensuring the communication quality of high-speed communication signals and reducing signal distortion.

[0056] like Figure 2 As shown, the integrated laser driver circuit in this embodiment mainly includes key components such as a laser driver chip, a laser chip, a pulse generation circuit, and a microcontroller.

[0057] The laser driver chip is used to modulate the received electrical signal, for example, by generating a modulation current and applying it to the bias current to form a driving signal, which is used to drive the laser in the laser chip to emit light, thereby realizing the conversion of electrical signal to optical signal (electro-optic conversion).

[0058] In this embodiment, the laser driver chip includes multiple driving channels. For cases where the laser chip contains n lasers, the laser driver chip should include at least 2n driving channels. Two driving channels drive one laser in a time-division manner to perform electro-optical conversion and generate optical communication signals and OTDR detection optical pulses in a time-division manner, so as to complete the isolation and switching of the two functions of high-speed communication and network detection.

[0059] In some embodiments, for multi-channel fiber optic networks, n is an integer greater than 1.

[0060] Specifically, in this embodiment, the laser driver chip is a driver chip array with 2n channels. The n-channel driver chip array can be used to construct n high-speed communication signal driving channels. These channels receive and modulate the n high-speed communication signals, and then drive the n lasers in the laser chip to convert these signals into n optical communication signals, performing multi-channel fiber optic network communication. The remaining n-channel driver chip array is used to construct n OTDR driving channels. These channels receive and modulate pulse signals used for OTDR testing, and then drive the n lasers in the laser chip to convert these pulse signals into n OTDR detection optical pulses, performing multi-channel fiber optic network diagnostic functions.

[0061] The selection and switching between the high-speed communication drive channel and the OTDR drive channel is achieved by the microcontroller writing channel selection instructions to the registers inside the laser driver chip.

[0062] To shorten the wiring length between the laser driver chip and the laser chip and avoid introducing noise interference, the n odd-numbered drive channels (1, 3, 5, ..., 2n-1) on the laser driver chip can be arranged in the order of 2n drive channels. These n channels are used as high-speed communication signal drive channels, and the n even-numbered drive channels (2, 4, 6, ..., 2n) are used as OTDR drive channels. By alternating the arrangement of the n high-speed communication drive channels and n OTDR drive channels on the laser driver chip, adjacent sets of high-speed communication drive channels and OTDR drive channels can be selected to connect to the same laser in the laser chip. Simultaneously, the laser chip and the laser driver chip are configured to be arranged side-by-side, adjacent to each other, and located at the output terminal (OUT) of the drive channel of the laser driver chip. i On the side where it is located, combined Figure 2 , Figure 3 As shown, the two chips can be directly connected by gold wire bonding without needing to go through the internal traces of the substrate 100. Therefore, problems such as impedance discontinuity, high signal noise, and distortion of high-speed communication signal quality will not occur.

[0063] Specifically, the substrate 100 is a PCB circuit board on which electronic components such as a microcontroller, a pulse generation circuit, a laser driver chip 200, and a laser chip 300 are arranged.

[0064] The laser driver chip 200 is a bare die, directly bonded to the substrate 100, such as... Figure 3 As shown. In some embodiments, the lower surface of the laser driver chip 200 can be bonded to the substrate 100 with adhesive such as silver paste. The laser driver chip 200 and the substrate 100 are electrically connected by gold wire bonding via leads 500, and then electrically connected to the electrical interface of the optical module, the pulse generation circuit, and the microcontroller through the internal wiring of the substrate 100.

[0065] The laser chip 300 is also a bare die, and a ceramic block 400 can be placed between its lower surface and the substrate 100 to achieve insulation and isolation between the laser chip 300 and the substrate 100. In some embodiments, the lower surface of the laser chip 300 can be glued to the ceramic block 400, and the ceramic block 400 can be glued to the substrate 100. The laser chip 300 and the laser driver chip 200 are electrically connected by gold wire bonding 600. Because the laser chip 300 and the laser driver chip 200 are placed close together and directly connected by gold wire bonding, and the gold wire 600 is short, high-speed signal quality can be guaranteed and distortion can be prevented.

[0066] In some embodiments, adapter pads 401 may be provided on the ceramic block 400, such as Figure 4 As shown, the laser driver chip 200 is first wire-bonded to the adapter pad 401 of the ceramic block 400, and then wire-bonded to the laser chip 300 to solve the problem that the laser driver chip 200 is not convenient to be directly wire-bonded to the laser chip 300 in some cases.

[0067] For laser driver chips with 2n differential drive channels, such as Figure 2 As shown, it includes 2n differential input terminals IN. i+ 2n-channel differential input IN i- 2n-way differential + output terminal OUT i+ and 2n-way differential output OUT i- Where i = 1, 2, ..., 2n. The differential + input IN of the n high-speed communication drive channels can be... i+ (i=1,3,5,……,2n-1) are connected to the transmitter of the electrical interface on the optical module, combined with Figure 7 As shown, it receives n high-speed communication signals transmitted in parallel from the user side, and the differential + output terminal OUT of the n high-speed communication drive channel. i+(i=1,3,5,……,2n-1) are then connected one-to-one with the anodes of the n lasers in the laser chip. The differential + input terminal IN of the n OTDR drive channels is then connected. i+ (i=2,4,6,……,2n) After being connected in parallel, they are connected to the pulse generation circuit to receive the pulse signal output by the pulse generation circuit. The differential + output terminal OUT of the n OTDR drive channels i+ (i=2,4,6,...,2n) are then connected one-to-one with the anodes of the n lasers in the laser chip. The differential output terminal OUT of the n high-speed communication drive channels can be selected. i- (i=1,3,5,……,2n-1) or the differential output terminal OUT of n OTDR drive channels i- (i=2,4,6,……,2n) are connected one-to-one with the cathodes of the n lasers in the laser chip to control the on / off state of the power supply circuit of the n laser array.

[0068] To simplify the circuit structure of the optical module and facilitate its small-size packaging, this embodiment designs a pulse generation circuit to output pulse signals for OTDR testing, which are then transmitted to the differential + input terminal IN of the n OTDR drive channels of the laser driver chip. i+ (i=2,4,6,……,2n), the microcontroller controls the pulse generation circuit to generate the required pulse signal at a certain moment, and controls which channel of the 2, 4, 6, …, 2n channel the pulse signal enters by controlling the register inside the laser driver chip.

[0069] For multi-channel optical modules, a pulse generation circuit needs to be designed to output narrow pulse signals in the nanosecond or even picosecond range in order to drive the laser chip to emit OTDR detection optical pulses that meet the testing requirements of multi-channel fiber optic networks. The reasons are as follows:

[0070] Currently, optical modules with integrated OTDR functionality are mainly designed for long-distance single-mode fiber optic networks, with fiber optic links ranging from several kilometers to tens of kilometers in length. The width of the OTDR detection light pulse emitted by such OTDR optical modules is generally tens of nanoseconds or more, corresponding to a fiber optic distance resolution of several meters.

[0071] For multi-channel fiber optic networks, the length of fiber optic links is generally in the range of a few meters to three hundred meters, and the distance between two event points (such as two connectors) is tens of centimeters or less. Therefore, optical pulses of tens of nanoseconds cannot meet the OTDR testing requirements of multi-channel fiber optic networks.

[0072] Therefore, in order to be suitable for short-distance multi-channel fiber optic transmission links, it is necessary to configure narrow pulse optical signal generation circuits at the nanosecond or even picosecond level in multi-channel OTDR optical modules.

[0073] Therefore, this embodiment is designed as follows: Figure 5 The pulse generation circuit shown, in conjunction with the microcontroller, outputs narrow pulse signals at the nanosecond or even picosecond level. After being modulated by the laser driver chip, the laser chip is driven to emit narrow pulse light signals at the nanosecond or even picosecond level.

[0074] Specifically, the pulse generation circuit in this embodiment includes a NOT gate and an AND gate. The microcontroller outputs two pulse signals, P1 and P2, with a certain delay between them. This delay can be controlled by the microcontroller through the time difference between the outputs of the two pulse signals P1 and P2. One pulse signal, P1, is transmitted to one input of the AND gate. The other pulse signal, P2, is inverted by the NOT gate to obtain an inverted pulse signal -P2, which is then transmitted to the other input of the AND gate. The AND gate performs an AND operation on the received two pulse signals P1 and -P2 to generate an output pulse, Pulse, which is transmitted to the input of the n-channel OTDR drive channel of the laser driver chip.

[0075] Because there is a time delay between the two inverted pulse signals P1 and -P2 entering the AND gate, such as Figure 6 As shown, the pulse width of the output pulse Pulse generated after the AND gate is equal to or slightly less than the delay time between the two inverted pulse signals P1 and -P2. Therefore, by adjusting the time difference between the two pulse signals P1 and P2 output by the microcontroller, a narrow pulse electrical signal Pulse in the nanosecond or picosecond range can be obtained. Modulating the narrow pulse electrical signal Pulse and driving the laser chip to emit light can generate a narrow pulse optical signal in the nanosecond or picosecond range (i.e., OTDR detection optical pulse) to meet the testing requirements of multi-channel fiber optic networks.

[0076] This embodiment generates nanosecond or picosecond-level OTDR detection optical pulses by controlling the delay between two pulse signals P1 and P2. The solution is simple, requiring only a small number of gate devices, which are small in size, facilitating integration and contributing to the miniaturization of optical module packaging. Furthermore, by adjusting the delay between the two pulse signals P1 and P2 output by the microcontroller, the pulse width of the generated OTDR detection optical pulses can be adjusted, providing technical support for subsequent intelligent pulse width adjustment.

[0077] Based on the above-described integrated laser driver circuit, this embodiment designs as follows: Figure 7The multi-channel optical module shown has multi-channel parallel high-speed communication function and multi-channel parallel optical fiber network intelligent detection function. The two functions are multiplexed and isolated by time division multiplexing, and do not affect each other. It can monitor the connection status of multi-channel optical fiber network without disconnecting the optical fiber network.

[0078] Its working principle is: the microcontroller is configured via I... 2 The C-bus communicates with the laser driver chip to initialize and configure the laser driver chip.

[0079] When performing high-speed communication, the microcontroller writes a channel selection instruction to the register in the laser driver chip, controlling the laser driver chip to open its n high-speed communication drive channels 1,3,5,...,2n-1 to receive n high-speed communication signals transmitted in parallel from the user side through the electrical interface transmitter on the optical module, while simultaneously closing its n OTDR drive channels 2,4,6,...,2n.

[0080] The n high-speed communication driving channels 1, 3, 5, ..., 2n-1 in the laser driver chip are independent of each other. The output bias current and modulation current drive the n lasers in the laser chip to emit light, forming an optical communication signal that enters the optical fiber through the subsequent optical path array and is output to the outside from the optical interface of the optical module.

[0081] The n-channel optical communication signals emitted from the opposite optical module enter the optical module of this embodiment through the optical interface. After being focused by the optical path array, they are transmitted to the communication signal detector to complete the conversion from optical signal to electrical signal. The n-channel electrical signals output by the communication signal detector are amplified and shaped by the communication signal amplifier, and then output to the user side through the electrical interface receiver on the optical module.

[0082] When fault detection is required in an optical fiber network, the microcontroller first controls the n high-speed communication drive channels 1, 3, 5, ..., 2n-1 in the laser driver chip to shut down through the registers in the laser driver chip. Then, it controls the pulse generation circuit to output a pulse signal that meets the requirements of OTDR testing and transmits it to the n OTDR drive channels of the laser driver chip.

[0083] The microcontroller writes channel selection instructions to the registers in the laser driver chip. Through these registers, the microcontroller controls the laser driver chip to sequentially open its n OTDR drive channels 2, 4, 6, ..., 2n. This causes pulse signals to be sequentially loaded onto the n lasers from their corresponding channels, undergoing electro-optical conversion to generate n OTDR detection optical pulses. These OTDR detection optical pulses then enter the optical fiber via a subsequent optical path array and, through the optical interface of the optical module, enter the optical fiber link under test.

[0084] During the propagation of optical pulses in an optical fiber link, OTDR (Optical Detector Resonance Device) generates reflected signals when encountering fiber joints, breaks, defects, end faces, and tail ends. Simultaneously, Rayleigh scattering occurs due to inhomogeneous particles in the fiber material. These back-reflected and scattered signals are received by the optical path array and fed back into the OTDR detector to convert the back-reflected optical signal into an electrical signal. This signal is then sent to the OTDR processing circuit for amplification, shaping, filtering, and other processing before being sent to the microcontroller. The microcontroller's built-in ADC (Analog-to-Digital Converter) sampling circuit completes the sampling, obtaining back-reflected signal strength data that varies over time. The microcontroller can further process this back-reflected signal strength data to obtain data on the variation of back-reflected signal strength with fiber distance, thereby generating OTDR test curves and / or event tables. This data is then transmitted through the optical module's data interface (e.g., I / O). 2 Output and report (using C interface or SPI interface, etc.).

[0085] During the operation of the optical module, the microcontroller monitors the internal operating voltage, chip temperature, transmitted optical power, and received optical power in real time to ensure the safe operation of the optical module.

[0086] This embodiment designs an optical module that integrates high-speed communication with multiple parallel channels and multi-channel fiber optic network detection functions for data center communication networks and special optical network applications with a large number of fiber optic channels and complex connections. It can be widely used in fiber optic communication or Internet of Things fiber optic networks such as the Internet, vehicle-mounted, airborne, and terrestrial networks. Without disconnecting the fiber optic network, it can automatically detect the connection status of multi-channel fiber optic networks, making it particularly suitable for monitoring network connection status in scenarios with complex connections or where disassembly is difficult.

[0087] Of course, the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions claimed by this utility model.

Claims

1. An integrated laser driver circuit for an OTDR optical module, characterized in that, include: A laser chip, which is a laser array with n channels, is used for electro-optical conversion, where n>1; A laser driver chip, which is a driver chip array with 2n channels, includes: --High-speed communication driving channel, which has n channels, is used to receive n high-speed communication signals and modulate them to drive the n lasers in the laser chip to convert the n high-speed communication signals into n optical communication signals; --OTDR drive channel, which has n channels, receives pulse signals for OTDR testing and modulates them to drive the n lasers in the laser chip to convert the n pulse signals into n OTDR detection optical pulses; -- A register, used to receive channel selection instructions; the laser driver chip switches between the high-speed communication drive channel and the OTDR drive channel according to the channel selection instructions written in the register; A pulse generation circuit generates pulse signals for OTDR testing and transmits them to the OTDR drive channel; The microcontroller generates a channel selection instruction, sends it to the register, and controls the pulse generation circuit to output the pulse signal used for OTDR testing.

2. The integrated laser driver circuit for an OTDR optical module according to claim 1, characterized in that, The n high-speed communication drive channels and the n OTDR drive channels are arranged alternately on the laser driver chip, and an adjacent set of high-speed communication drive channels and OTDR drive channels are selected to connect to the same laser in the laser chip.

3. The integrated laser driver circuit for an OTDR optical module according to claim 2, characterized in that, The laser driver chip has 2n differential driving channels. In a group of high-speed communication driving channels and OTDR driving channels connected to the same laser, two differential + output terminals are connected to the anode of the laser, and one differential - output terminal is connected to the cathode of the laser.

4. The integrated laser driver circuit for an OTDR optical module according to any one of claims 1 to 3, characterized in that, The laser driver chip and the laser chip are arranged side by side on the substrate, with the laser chip located on the side of the output end of the driving channel of the laser driver chip, and the two chips are connected by gold wire bonding.

5. The integrated laser driver circuit for an OTDR optical module according to claim 4, characterized in that, A ceramic block is placed between the lower surface of the laser chip and the substrate.

6. The integrated laser driver circuit for an OTDR optical module according to claim 5, characterized in that, A bonding pad is provided on the ceramic block, and the laser driver chip is wire-bonded to the bonding pad, thereby connecting the laser chip through the bonding pad.

7. The integrated laser driver circuit for an OTDR optical module according to claim 4, characterized in that, The laser driver chip is a bare die, which is directly bonded to the substrate; The input end of the high-speed communication drive channel of the laser driver chip is connected to the substrate by gold wire bonding, and is connected to the electrical interface of the optical module through the internal wiring of the substrate. The electrical interface receives n high-speed communication signals transmitted in parallel from the user side.

8. The integrated laser driver circuit for an OTDR optical module according to any one of claims 1 to 3, characterized in that, The microcontroller outputs two pulse signals to the pulse generation circuit, controlling the pulse generation circuit to output narrow pulse signals for OTDR testing in the nanosecond or picosecond range, which in turn output OTDR detection light pulses with pulse widths in the nanosecond or picosecond range through the laser driver chip and the laser chip.

9. The integrated laser driver circuit for an OTDR optical module according to claim 8, characterized in that, The pulse generation circuit includes: The NOT gate is used to invert one pulse signal output by the microcontroller; An AND gate is used to perform an AND operation on the pulse signal output by the NOT gate and another pulse signal output by the microcontroller to generate an output pulse; The microcontroller adjusts the time difference between the two output pulse signals to change the pulse width of the output pulse generated by the AND gate, thereby generating narrow pulse signals at the nanosecond or picosecond level.

10. An optical module, characterized in that, The device includes a housing and an integrated laser driving circuit for an OTDR optical module as described in any one of claims 1 to 9, encapsulated within the housing.

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