Multi-physical field coupling analysis system for continuous wave distributed feedback semiconductor laser

Abstract

The application relates to a multi-physical field coupling analysis system of a continuous wave distributed feedback semiconductor laser, which comprises: a semiconductor module for calculating the net carrier density distribution and the electric field distribution of the active region of a target laser; a quantum mechanics module for determining the optical gain according to the carrier density; an optical module for calculating the lasing wavelength and the threshold gain of the target laser and generating a performance prediction result of the target laser; and a thermal module for calculating the temperature change of the target laser and feeding back to the semiconductor, quantum mechanics and optical modules to update the material parameters and accurately predict the performance influence under high injection current, such as output power saturation and wavelength redshift. Thus, the problems of the related art, such as the loose multi-physical field coupling, the dependence on experimental calibration parameters, the poor universality and the low simulation result accuracy, are solved, and the nonlinear behavior of the semiconductor laser caused by self-heating can be accurately predicted without experimental calibration parameters.

Description

Technical Field

[0001] This application relates to the field of semiconductor optoelectronic device simulation and design technology, and in particular to a multiphysics coupling analysis system for a continuous wave distributed feedback semiconductor laser. Background Technology

[0002] Currently, distributed feedback (DFB) semiconductor lasers are widely used in fiber optic communication and microwave photonics systems due to their single longitudinal mode output, narrow linewidth, and good wavelength stability. Accurately predicting their nonlinear behavior at high power operating points (such as output power saturation and lasing wavelength redshift with current) is crucial during the device design phase.

[0003] In related technologies, methods for simulating semiconductor lasers mainly fall into two categories: first, separating optical modes, carrier distribution, and thermal effects; and second, using simplified phenomenological models to approximate the nonlinear characteristics of semiconductor lasers. Most simulation models employ isothermal assumptions or only consider unidirectional thermo-optical coupling, such as rate equation-based methods. Other phenomenological models at the Technology Computer-Aided Design (TCAD) level rely on pre-calibrated phenomenological parameters such as ABC recombination coefficients and differential gain. Additionally, some simulation methods directly use macroscopic gain formulas for simulation calculations.

[0004] However, simulation methods in related technologies fail to consider the dynamic changes in carrier mobility and recombination mechanisms caused by temperature variations, as well as the reverse effects of these changes on optical modes and gain spectra. This makes it difficult to accurately predict various complex nonlinear behaviors induced by device self-heating under high injection current conditions. Furthermore, some TCAD phenomenological models rely on experimentally calibrated phenomenological parameters such as ABC recombination coefficients and differential gain. These parameters vary significantly with different device structures, resulting in poor model universality and difficulty in reflecting the internal microscopic physical mechanisms of the device. In addition, directly using macroscopic gain expressions ignores the strain effects of multiple quantum well (MQW) structures, light-heavy hole coupling, and the microscopic heat source distribution formed by SRH / Auger nonradiative recombination. This ultimately leads to significant discrepancies between simulated predictions of wavelength redshift coefficients and saturation power and actual values, which urgently need to be addressed. Summary of the Invention

[0005] This application provides a multiphysics coupling analysis system for continuous wave distributed feedback semiconductor lasers to solve the problems of loose multiphysics coupling, reliance on experimental calibration parameters, poor versatility, and low accuracy of simulation results in related technologies. It can accurately predict the nonlinear behavior caused by self-heating of semiconductor lasers without the need for experimental calibration parameters.

[0006] The first aspect of this application provides a multiphysics coupling analysis system for a continuous-wave distributed feedback semiconductor laser, comprising: The semiconductor module is used to calculate the net carrier density distribution, electric field distribution, and non-radiative composite heat source in the active region of the target laser based on the operating current and the current temperature field fed back by the thermal module. The quantum mechanics module is used to solve the multi-quantum well energy level structure and wave function based on the preset Schrödinger equation, the band gap width determined by the net carrier density distribution provided by the semiconductor module and the current temperature field, and the gain spectrum by using k·p perturbation theory, without the need to introduce empirical fitting parameters. The optical module is used to iteratively solve the lasing wavelength and threshold gain of the target laser based on the transfer matrix method combined with the finite difference method, according to the gain spectrum provided by the quantum mechanics module and the refractive index distribution determined by the current temperature field, and generate the output performance prediction results of the target laser based on the lasing wavelength and threshold gain. The thermal module is used to calculate Joule heat based on the operating current of the target laser, and based on the preset heat conduction equation, determine the current temperature field of the target laser according to the nonradiative recombination heat and Joule heat provided by the semiconductor module, so as to update the band gap and carrier mobility of the semiconductor module and the refractive index of the optical module through the current temperature field.

[0007] Optionally, in some embodiments, the preset heat conduction equation is: ; in, It is a divergence operator; Thermal conductivity is temperature-dependent; For temperature gradient; This represents the current temperature field. Joules of heat; This is non-radiative heat.

[0008] Optionally, in some embodiments, the semiconductor module is specifically used for: Collect the operating current of the target laser; Based on the operating current and the current temperature field, the carrier mobility is determined, the drift-diffusion equation is solved, and the electric field distribution, electron concentration distribution, and hole concentration distribution inside the target laser are calculated. The net carrier density and nonradiative recombination heat of the active region of the target laser are calculated based on the electric field distribution, electron concentration distribution, and hole concentration distribution.

[0009] Optionally, in some embodiments, the quantum mechanics module is specifically used for: In response to the received carrier density and current temperature field, the bandgap width of the semiconductor material is updated using the current temperature field. Based on the preset Schrödinger equation, the energy eigenvalues ​​of electrons, heavy holes, light holes and wave functions are calculated according to the carrier density. The optical gain parameters are determined based on the energy eigenvalues ​​of electrons, heavy holes, and light holes, and their wave functions.

[0010] Optionally, in some embodiments, the optical module is specifically used for: The refractive index consists of the reference refractive index at the reference temperature and the incremental term that changes with temperature, wherein the rate of change of the refractive index with temperature depends on the material composition of the active region or waveguide layer of the laser. The optical module calculates the transverse optical field distribution based on the updated refractive index distribution using the finite difference method to obtain the effective refractive index and optical confinement factor at the current temperature, and uses the transfer matrix method combined with complex refractive index iteration to solve for the lasing wavelength and threshold gain of the target laser.

[0011] A second aspect of this application provides a multiphysics coupling analysis method for a continuous-wave distributed feedback semiconductor laser, comprising the following steps: Collect the operating current of the target laser and initialize the current temperature field to the ambient temperature. Based on the operating current and the current temperature field, calculate the net carrier density, electric field distribution and nonradiative recombination heat of the active region of the target laser. Based on the pre-defined Schrödinger equation, the energy level structure and gain spectrum are determined according to the band gap width determined by the carrier density and the current temperature field. Based on the refractive index distribution determined by the gain spectrum and the current temperature field, the lasing wavelength and threshold gain of the target laser are calculated, and the light prediction result of the target laser is generated based on the lasing wavelength and threshold gain. Based on the preset heat conduction equation, the current temperature field is updated by the thermal module according to the non-radiative composite heat source.

[0012] Therefore, the embodiments of this application have at least the following beneficial effects: (1) High-precision prediction of nonlinear behavior: By introducing a complete thermal-optical-electric closed-loop coupling and a microscopic non-radiative heat source, the embodiments of this application can accurately reproduce the power saturation phenomenon and wavelength monotonic redshift characteristics observed in experiments under high current, with errors significantly lower than those of constant temperature models in related technologies.

[0013] (2) No empirical fitting parameters required: All input parameters in the embodiments of this application are the basic physical constants of the material (such as effective mass, thermal conductivity, composite lifetime, etc.), which makes the model have strong versatility and predictive ability, and is particularly suitable for the pre-design of new structure DFB lasers.

[0014] (3) Clear physical mechanism: The embodiments of this application can quantify and analyze the specific contributions of self-heating effect, carrier leakage and bandgap shrinkage to device performance, providing a theoretical basis for the thermal management design and structural optimization of the device.

[0015] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0016] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a block diagram of a multiphysics coupling analysis system for a continuous-wave distributed feedback semiconductor laser according to an embodiment of this application; Figure 2 This is a block diagram illustrating a cross-domain multiphysics coupling modeling of a CW-DFB laser according to an embodiment of this application; Figure 3 This is a flowchart of a multiphysics coupling analysis method for a continuous wave distributed feedback semiconductor laser according to an embodiment of this application. Detailed Implementation

[0017] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0018] The following description, with reference to the accompanying drawings, describes a multiphysics coupling analysis system for a continuous-wave distributed feedback semiconductor laser according to an embodiment of this application. Addressing the problems mentioned in the background art regarding the loose multiphysics coupling, reliance on experimental calibration parameters, poor versatility, and low accuracy of simulation results in related simulation methods, this application provides a multiphysics coupling analysis system for a continuous-wave distributed feedback semiconductor laser. This system can calculate the net carrier density and nonradiative recombination heat of the active region of the target laser using a semiconductor module, determine the optical gain parameters based on the carrier density using a quantum mechanics module, and calculate the lasing wavelength and threshold gain of the target laser using the optical gain parameters. Finally, it generates a prediction result for the target laser based on the lasing wavelength and threshold gain. This solves the problems of loose multiphysics coupling, reliance on experimental calibration parameters, poor versatility, and low accuracy of simulation results in related simulation methods, enabling accurate prediction of the nonlinear behavior induced by self-heating of the semiconductor laser without the need for experimental calibration parameters.

[0019] Specifically, Figure 1 This is a block diagram of a multiphysics coupling analysis system for a continuous-wave distributed feedback semiconductor laser provided in an embodiment of this application.

[0020] like Figure 1 As shown, the multiphysics coupling analysis system 10 for the continuous wave distributed feedback semiconductor laser includes: a semiconductor module 100, a quantum mechanics module 200, an optical module 300, and a thermal module 400.

[0021] The semiconductor module 100 is used to calculate the net carrier density distribution, electric field distribution, and non-radiative composite heat source of the active region of the target laser based on the operating current and the current temperature field fed back by the thermal module. The quantum mechanics module 200 is used to solve for the multi-quantum well energy level structure and wavefunction using k·p perturbation theory based on the preset Schrödinger equation and the bandgap width determined by the net carrier density distribution and current temperature field provided by the semiconductor module 100, thus determining the gain spectrum without introducing empirical fitting parameters. The optical module 300 is used to calculate the gain spectrum based on the transfer matrix method combined with the finite difference method, according to the data provided by the quantum mechanics module. The system uses the provided gain spectrum and the refractive index distribution determined by the current temperature field to iteratively solve the lasing wavelength and threshold gain of the target laser, and generates the output performance prediction result of the target laser based on the lasing wavelength and threshold gain; the thermal module 400 is used to calculate Joule heat based on the operating current of the target laser, and based on the preset heat conduction equation, it determines the current temperature field of the target laser based on the nonradiative recombination heat and Joule heat provided by the semiconductor module 100, so as to update the band gap, carrier mobility and refractive index of the semiconductor module 100 and the optical module in reverse through the current temperature field, so as to realize the self-consistent iterative solution of the multiphysics field.

[0022] Specifically, embodiments of this application can construct a multiphysics coupling analysis system 10 for a continuous-wave distributed feedback semiconductor laser, comprising a semiconductor module 100, a quantum mechanics module 200, an optical module 300, and a thermal module 400, capable of self-consistent iteration. The semiconductor module 100 employs a semiconductor carrier transport model to collect the operating current of the target laser and, based on this current, calculates the net carrier density and nonradiative recombination heat of the active region of the target laser. The quantum mechanics module 200 employs a quantum gain model to determine the optical gain parameters based on the carrier density according to a pre-defined Schrödinger equation. The optical module 300 employs an optical model to calculate the lasing wavelength and threshold gain of the target laser based on the optical gain parameters and generates a light prediction result for the target laser based on the lasing wavelength and threshold gain. Furthermore, the modules interact with each other through key physical quantities such as carrier density, temperature, refractive index, and gain coefficient, forming a closed-loop feedback.

[0023] Furthermore, the aforementioned thermal module 400 can calculate Joule heat based on the operating current of the target laser, and determine the current temperature field of the target laser based on the preset heat conduction equation, according to the nonradiative recombination heat and Joule heat, so as to update the bandgap and carrier mobility of the semiconductor module 100 and the refractive index of the optical module 300 through the current temperature field.

[0024] Specifically, in this embodiment, Joule heating can be calculated based on the operating current of the target laser, and a preset heat conduction equation can be constructed. The preset heat conduction equation is as follows: ; in, It is a divergence operator; Thermal conductivity is temperature-dependent; For temperature gradient; This represents the current temperature field. Joules of heat; This is non-radiative heat.

[0025] Furthermore, embodiments of this application can determine the current temperature field T of the target laser based on a preset heat conduction equation, using Joule heating and nonradiative recombination heat (SRH / Auger) as the heat source, and use the thermal module 400 to feed back the current temperature field T to the semiconductor module 100, the quantum mechanics module 200, and the optical module 300: on the one hand, the parameters of the semiconductor module 100 are updated using the current temperature field, causing a band gap Changes in carrier mobility µ(T) and Fermi-Dirac distribution affect gain and carrier distribution. Furthermore, updating the temperature-dependent refractive index n(T) in the optical module 300 (thermo-optic effect) causes a redshift. In summary, the embodiments of this application can achieve a self-consistent solution through iterative loops until temperature, carrier density, and optical power converge.

[0026] Therefore, this application proposes a self-consistent multiphysics simulation method for CW-DFB lasers based on first-principles calculations. It constructs a closed-loop iterative coupling framework of four modules: optics, semiconductor carrier transport, quantum mechanical gain, and thermal dynamics. This method jointly solves the multi-field control equations, addressing the problems of multiphysics decoupling, reliance on empirical parameters, and insufficient description of microscopic mechanisms in related technologies. It can accurately predict power saturation characteristics and wavelength redshift phenomena under high injection current without the need for empirical fitting parameters, making it suitable for the design and optimization of high-performance DFB lasers in optical communication, microwave photonics systems, and lidar. Furthermore, this application explicitly includes local heat sources generated by SRH and Auger recombination in the thermal module to accurately reflect the temperature gradient within the active region and its reaction on carrier transport, thereby achieving microscopic non-radiative heat source modeling.

[0027] Furthermore, to enable those skilled in the art to better understand the specific working principle of the semiconductor module 100 in the multiphysics coupling analysis system 10 for the continuous wave distributed feedback semiconductor laser of this application, the following description is provided in conjunction with specific embodiments.

[0028] As some possible implementation methods, in some embodiments, the semiconductor module 100 is specifically used for: acquiring the operating current of the target laser; determining the carrier mobility based on the operating current and the current temperature field, solving the drift-diffusion equation, calculating the electric field distribution, electron concentration distribution, and hole concentration distribution inside the target laser; and calculating the net carrier density and nonradiative recombination heat of the active region of the target laser based on the electric field distribution, electron concentration distribution, and hole concentration distribution.

[0029] Specifically, embodiments of this application can solve for the electric field distribution, electron concentration distribution, and hole concentration distribution inside the target laser based on the drift-diffusion model and the Poisson equation. The drift-diffusion model explicitly includes Shockley-Reid-Hall (SRH), radiative recombination, and Auger recombination mechanisms, and the Poisson equation is:

[0030] in, It is a divergence operator; It is the dielectric constant; The gradient of the electric potential; It is the electric potential; It is the elementary charge; Hole concentration; Electron concentration; The concentration of ionized donor impurities; The concentration of ionized acceptor impurities.

[0031] Therefore, the embodiments of this application can fully characterize various carrier recombination processes based on the drift-diffusion model, accurately calculate the net carrier density and non-radiative recombination heat source in the active region, and provide reliable semiconductor field input for subsequent multiphysics self-consistent coupling simulation.

[0032] Furthermore, to enable those skilled in the art to better understand the specific working principle of the quantum mechanics module 200 in the multiphysics coupling analysis system 10 for the continuous wave distributed feedback semiconductor laser of this application, the following description is provided in conjunction with specific embodiments.

[0033] As some possible implementation methods, in some embodiments, the quantum mechanics module 200 is specifically used to: in response to receiving the carrier density and the current temperature field, update the bandgap width of the semiconductor material using the current temperature field, calculate the energy eigenvalues ​​of electrons, heavy holes, and light holes, and the wave function based on the preset Schrödinger equation and the carrier density; and determine the optical gain parameters based on the energy eigenvalues ​​of electrons, heavy holes, and light holes, and the wave function.

[0034] Specifically, embodiments of this application can employ effective mass approximation and... k·p Perturbation theory is used to solve the pre-defined Schrödinger equation, yielding the energy eigenvalues ​​of electrons, heavy holes, and light holes, as well as their wave functions. This model directly starts from the material physics parameters, eliminating the need for empirical fitting of gain parameters.

[0035] Therefore, the embodiments of this application can be based on effective quality and k·p The theory calculates the gain spectrum from first principles to avoid using phenomenological ABC parameters or empirically fitted optical limitation factors, thereby achieving the gain calculation.

[0036] Furthermore, to enable those skilled in the art to better understand the specific working principle of the optical module 300 in the multiphysics coupling analysis system 10 for the continuous wave distributed feedback semiconductor laser of this application, the following description is provided in conjunction with specific embodiments.

[0037] As one possible implementation, in some embodiments, the optical module 300 is specifically used for: refractive index determined by a reference temperature. The reference refractive index The optical module 300, based on the updated refractive index distribution n(T), calculates the transverse optical field distribution using the finite difference method to obtain the effective refractive index at the current temperature. This is in addition to the incremental term varying with temperature, where the rate of change of refractive index with temperature depends on the material composition of the laser's active region or waveguide layer. The optical confinement factor Γ is calculated, and the lasing wavelength and threshold gain of the target laser are solved by combining the transfer matrix method with the complex refractive index iteration. The relationship between the material refractive index n(T) and temperature T is used to update the propagation constant and transfer matrix of the optical cavity.

[0038] Specifically, embodiments of this application can solve the wave equation based on the transfer matrix method (TMM) combined with the finite difference method (FDM). The transfer matrix method is used to handle the periodic structure of the DFB grating, while the finite difference method is used to accurately calculate the transverse optical field distribution and confinement factor of the ridge waveguide. Through iterative solving, embodiments of this application can determine the lasing wavelength of the target laser. and threshold gain .

[0039] Therefore, the embodiments of this application can introduce a temperature-dependent refractive index model, combine the finite difference method and the transfer matrix method to complete the iterative calculation of the optical field, fully consider the refractive index temperature effect caused by the material composition, accurately update the optical cavity propagation parameters, realize the temperature dependence characteristics simulation of the laser lasing wavelength and threshold gain, and improve the accuracy of the laser thermal characteristic simulation results.

[0040] Furthermore, to enable those skilled in the art to better understand the multiphysics coupling analysis system 10 for continuous wave distributed feedback semiconductor lasers of this application, the following description is provided in conjunction with specific embodiments.

[0041] Specifically, this application example uses a typical 1550 nm InP-based CW-DFB laser as an example for simulation verification. First, this application example needs to define the structural parameters of the laser, including the geometric dimensions and doping concentration of the n-InP substrate, waveguide layer, AlGaInAs multi-quantum-well active region, p-InP confinement layer, and DFB grating. Second, this application example needs to perform initial solutions: assuming the initial solution temperature is room temperature (25°C), the semiconductor module 100 is used to solve for the carrier distribution under low current, the quantum mechanics module 200 is used to calculate the gain spectrum, and the transfer matrix method (TMM) is used to determine the initial lasing wavelength.

[0042] Furthermore, this embodiment requires multiphysics iterative solutions. Specifically, the injected current is gradually increased, the Joule heating and nonradiative heat generated by SRH and Auger recombination are calculated, and a preset heat conduction equation is solved to obtain the current temperature field. Based on the current temperature field, the refractive index of the optical module 300 (causing a wavelength redshift), the band gap and carrier mobility of the semiconductor module 100 are updated, and the carrier distribution and gain are resolved until the power and temperature changes are less than a preset threshold, where the preset threshold can be 0.1%.

[0043] Furthermore, the embodiments of this application require simulation result analysis. The simulation results show: (1) LI characteristics: As the current increases, the output power first increases linearly and then saturates, which is consistent with the experimental data. If the thermal model is not included, the simulation results will show an unrealistic linear increase.

[0044] (2) Wavelength redshift: Simulation predicts that the lasing wavelength redshifts monotonically with current, mainly due to the effective refractive index caused by temperature increase. Increase( The predicted curve is highly consistent with the experimental measurement.

[0045] Therefore, this application embodiment constructs a complete thermally induced nonlinear closed-loop feedback mechanism by tightly and self-consistently coupling the four physical fields of optics, semiconductors, quantum gain, and thermal, rather than unidirectional or loosely connecting them. This mechanism establishes a complete thermally induced nonlinear closed-loop feedback mechanism: temperature → refractive index / band gap / carrier mobility → optical mode / carrier distribution / gain → heat source → temperature. Each module achieves self-consistent solution through iterative loops. Specifically, the thermal module comprehensively considers Joule heating and the combined SRH and Auger nonradiative heat sources, feeding back the solved temperature field to the optical and semiconductor modules and updating key parameters such as refractive index, band gap, and mobility in real time. The quantum mechanical module is based on… k·p The perturbation theory and effective mass approximation are used to solve the energy level structure of multiple quantum wells, which can directly calculate the material gain spectrum without introducing various empirical fitting parameters. The optical module combines the transfer matrix method and the finite difference method to accurately solve the resonant wavelength of the DFB grating and the confinement factor of the ridge waveguide, and considers the effect of temperature on the effective refractive index, so as to achieve accurate prediction of the laser wavelength redshift characteristics. This effectively solves the problems of loose multi-physics coupling, lack of self-consistency, reliance on empirical parameter fitting, and insufficient accuracy in describing quantum effects and microscopic heat sources in related technologies.

[0046] Furthermore, to enable those skilled in the art to better understand the multiphysics coupling analysis system 10 for continuous-wave distributed feedback semiconductor lasers of this application, the following is combined with... Figure 2 The specific embodiments shown will be described in detail.

[0047] Figure 2This is a block diagram illustrating a cross-domain multiphysics coupling modeling of a CW-DFB laser, provided as an embodiment of this application.

[0048] like Figure 2 As shown, the cross-domain multiphysics coupling modeling framework for the CW-DFB laser consists of a semiconductor module 100, a quantum mechanics module 200, an optical module 300, and a thermal module 400. The semiconductor module 100 generates and outputs carrier distribution data to the quantum mechanics module 200 based on electrical signals; the quantum mechanics module 200 calculates the gain and inputs it to the optical module 300. The thermal module 400 feeds back the temperature field to the other three modules to update temperature-related parameters; the optical module 300 outputs the optical prediction results of the target laser, and the heat source information generated by each module flows back to the thermal module. Thus, a closed-loop simulation solution system is formed that couples semiconductor, quantum mechanics, optical, and thermal fields.

[0049] The multiphysics coupling analysis system for continuous-wave distributed feedback semiconductor lasers proposed in this application can calculate the net carrier density and nonradiative recombination heat of the active region of the target laser through a semiconductor module, determine the optical gain parameters based on the carrier density through a quantum mechanics module, and calculate the lasing wavelength and threshold gain of the target laser based on the optical gain parameters through a quantum mechanics module. Finally, it generates the optical prediction results of the target laser based on the lasing wavelength and threshold gain. This solves the problems of loose multiphysics coupling, reliance on experimental calibration parameters, poor versatility, and low accuracy of simulation results in related technologies. It can accurately predict the nonlinear behavior induced by self-heating of semiconductor lasers without the need for experimental calibration parameters.

[0050] Next, referring to the accompanying drawings, the multiphysics coupling analysis method for continuous wave distributed feedback semiconductor lasers proposed in this application is described.

[0051] Figure 3 This is a flowchart of the multiphysics coupling analysis method for a continuous wave distributed feedback semiconductor laser proposed in an embodiment of this application.

[0052] like Figure 3 As shown, the multiphysics coupling analysis method for this continuous-wave distributed feedback semiconductor laser includes the following steps: In step S301, the operating current of the target laser is collected, and the current temperature field is initialized to the ambient temperature.

[0053] In step S302, based on the operating current and the current temperature field, the net carrier density, electric field distribution and nonradiative recombination heat of the active region of the target laser are calculated.

[0054] In step S303, based on the preset Schrödinger equation, the energy level structure is solved and the gain spectrum is determined according to the band gap width determined by the carrier density and the current temperature field.

[0055] In step S304, the lasing wavelength and threshold gain of the target laser are calculated based on the gain spectrum and the refractive index distribution determined by the current temperature field. The light prediction result of the target laser is generated based on the lasing wavelength and threshold gain. Based on the preset heat conduction equation, the current temperature field is updated by the thermal module according to the non-radiative composite heat source.

[0056] Specifically, firstly, this embodiment can collect the operating current of the target laser as the driving input and set the initial temperature field to the ambient temperature. Simultaneously, a preset threshold for determining iterative convergence is set, preparing initial conditions for subsequent multiphysics self-consistent solutions. Secondly, this embodiment can solve the Poisson equation and the carrier continuity equation based on the carrier mobility determined by the operating current and the current temperature field, calculating the electric field distribution, electron and hole concentration distribution in the active region. Thirdly, this embodiment can calculate the total heat source distribution within the active region based on the electric field distribution and carrier concentration obtained from the semiconductor module, combined with the Joule heating effect and non-radiative recombination mechanisms such as SRH and Auger, providing input for the thermal field solution.

[0057] Furthermore, firstly, this embodiment can utilize k·p perturbation theory to solve the Schrödinger equation, and combine the updated bandgap width and net carrier density from the current temperature field to calculate the energy eigenvalues ​​and wave functions of electrons, heavy holes, and light holes, thereby obtaining the gain spectrum. Secondly, this embodiment can use the transfer matrix method and the finite difference method, combined with the gain spectrum provided by the quantum mechanics module and the refractive index distribution determined by the current temperature field, to solve the wave equation and calculate the lasing wavelength, threshold gain, and output optical power of the target laser. Thirdly, this embodiment can use the total heat source term calculated by the semiconductor module to solve the preset heat conduction equation, obtaining the updated internal temperature field of the laser, reflecting the self-heating effect during device operation. Finally, this embodiment needs to determine whether the changes in the current output optical power and temperature field are less than a preset convergence threshold. If convergence has not occurred, the updated temperature field is fed back to the semiconductor module to update the mobility and bandgap parameters, and the process returns to step S302 to continue iterating; if convergence has occurred, the final simulation result is output.

[0058] It should be noted that the explanation of the above-described embodiment of the multiphysics coupling analysis system for a continuous-wave distributed feedback semiconductor laser also applies to the multiphysics coupling analysis method for the continuous-wave distributed feedback semiconductor laser in this embodiment, and will not be repeated here.

[0059] The multiphysics coupling analysis method for continuous-wave distributed feedback semiconductor lasers proposed in this application can calculate the net carrier density, electric field distribution, and nonradiative recombination heat of the active region of the target laser using a semiconductor module. A quantum mechanics module determines the optical gain parameters based on the carrier density, and a quantum mechanics module calculates the lasing wavelength and threshold gain of the target laser based on these parameters. Finally, it generates a prediction result for the target laser based on the lasing wavelength and threshold gain. This solves the problems of loose multiphysics coupling, reliance on experimental calibration parameters, poor versatility, and low accuracy of simulation results in related technologies. It can accurately predict the nonlinear behavior induced by self-heating of semiconductor lasers without the need for experimental parameter calibration.

[0060] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0061] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0062] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0063] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0064] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

Claims

1. A multiphysics coupling analysis system for a continuous-wave distributed feedback semiconductor laser, characterized in that, include: The semiconductor module is used to calculate the net carrier density distribution, electric field distribution, and non-radiative composite heat source in the active region of the target laser based on the operating current and the current temperature field fed back by the thermal module. The quantum mechanics module is used to solve the multi-quantum well energy level structure and wave function based on the preset Schrödinger equation, the net carrier density distribution provided by the semiconductor module and the band gap width determined by the current temperature field, and to determine the gain spectrum through k·p perturbation theory, without the need to introduce empirical fitting parameters. An optical module is used to iteratively solve for the lasing wavelength and threshold gain of the target laser based on the transfer matrix method combined with the finite difference method, according to the gain spectrum provided by the quantum mechanics module and the refractive index distribution determined by the current temperature field, and to generate a predicted output performance result of the target laser based on the lasing wavelength and the threshold gain. The thermal module is used to calculate Joule heat based on the operating current of the target laser, and determine the current temperature field of the target laser based on the nonradiative recombination heat and Joule heat provided by the semiconductor module according to the preset heat conduction equation, so as to update the band gap and carrier mobility of the semiconductor module and the refractive index of the optical module through the current temperature field.

2. The multiphysics coupling analysis system for a continuous-wave distributed feedback semiconductor laser according to claim 1, characterized in that, The preset heat conduction equation is: ； in, ·(·) represents the divergence operator; k(T) is the temperature-dependent thermal conductivity. T represents the temperature gradient; T represents the current temperature field; Q Joule Joules of heat; Q non-rad This is non-radiative heat.

3. The multiphysics coupling analysis system for a continuous-wave distributed feedback semiconductor laser according to claim 1, characterized in that, The semiconductor module is specifically used for: The operating current of the target laser is collected; The carrier mobility is determined based on the operating current and the current temperature field, the drift-diffusion equation is solved, and the electric field distribution, electron concentration distribution, and hole concentration distribution inside the target laser are calculated. The net carrier density and nonradiative recombination heat of the active region of the target laser are calculated based on the electric field distribution, the electron concentration distribution, and the hole concentration distribution.

4. The multiphysics coupling analysis system for a continuous-wave distributed feedback semiconductor laser according to claim 1, characterized in that, The quantum mechanics module is specifically used for: In response to receiving the carrier density and the current temperature field, the bandgap width of the semiconductor material is updated using the current temperature field, and the energy eigenvalues ​​of electrons, heavy holes, light holes, and wave functions are calculated based on the preset Schrödinger equation and the carrier density. The optical gain parameters are determined based on the energy eigenvalues ​​of the electrons, the heavy holes, the light holes, and the wave function.

5. The multiphysics coupling analysis system for a continuous-wave distributed feedback semiconductor laser according to claim 1, characterized in that, The optical module is specifically used for: The refractive index consists of a reference refractive index at a reference temperature and an incremental term that varies with temperature, wherein the rate of change of the refractive index with temperature depends on the material composition of the active region or waveguide layer of the laser. The optical module calculates the transverse optical field distribution based on the updated refractive index distribution using the finite difference method to obtain the effective refractive index and optical confinement factor at the current temperature, and uses the transfer matrix method combined with complex refractive index iteration to solve for the lasing wavelength and threshold gain of the target laser.

6. A multiphysics coupling analysis method for a continuous-wave distributed feedback semiconductor laser, characterized in that, The method is applied to a multiphysics coupling analysis system for a continuous-wave distributed feedback semiconductor laser as described in any one of claims 1-5, wherein the method includes the following steps: Collect the operating current of the target laser and initialize the current temperature field to the ambient temperature. Based on the operating current and the current temperature field, calculate the net carrier density, electric field distribution, and nonradiative recombination heat of the active region of the target laser. Based on the preset Schrödinger equation, the energy level structure and gain spectrum are determined according to the band gap width determined by the carrier density and the current temperature field. Based on the gain spectrum and the refractive index distribution determined by the current temperature field, the lasing wavelength and threshold gain of the target laser are calculated, and the light prediction result of the target laser is generated based on the lasing wavelength and the threshold gain. Based on the preset heat conduction equation, the current temperature field is updated by the thermal module according to the non-radiative composite heat source.

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