Laser device

Abstract

The application provides a kind of laser equipment, laser equipment includes first waveguide, second waveguide group and laser, second waveguide group includes third waveguide and fourth waveguide respectively arranged in the two sides of first waveguide;Laser includes: first ridge structure and second ridge structure;First ridge structure is excited to emit laser by applying driving current to first ridge structure, and the excitation mode of laser is single lobe far field base transverse mode;First ridge structure is excited to emit laser by applying excitation to first ridge structure and second ridge structure, and the excitation mode of laser is double lobe far field single high order mode.In this way, the laser can be switched between single lobe far field base transverse mode and double lobe far field single high order mode by changing driving current, so as to control the far field shape of laser, quickly switch single lobe far field and double lobe far field, which can ensure high power output of laser and narrow linewidth characteristics of laser.

Description

Technical Field

[0001] This invention relates to the field of laser technology, and in particular to a laser device. Background Technology

[0002] Currently, the far-field beam characteristics (including shape and divergence angle) of traditional semiconductor lasers are entirely limited by their inherent device structure, inherently lacking the ability for dynamic and active control. Attempts to artificially intervene in the far-field distribution must rely on complex additional structures such as high-order gratings, microelectromechanical systems (MEMS), and microlenses. This not only significantly increases system size, cost, and integration difficulty, but more seriously, these external control methods have fundamental limitations in their physical mechanisms: the control process is extremely inefficient, slow in response, and difficult to guarantee accuracy, and is highly susceptible to introducing additional optical losses and mode perturbations. Even more critically, while attempting to adjust the far-field, the laser's core performance indicators—such as output power and spectral linewidth—often suffer irreversible degradation: high power output is difficult to maintain, and narrow linewidth characteristics are easily disrupted, leading to severe degradation of the overall system performance.

[0003] Therefore, the existing technological approaches have an irreconcilable fundamental contradiction between achieving "high power and narrow linewidth" and "flexible and controllable far field," which has become a key bottleneck restricting the application of high-performance semiconductor lasers in advanced photonic systems. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a laser device that can control the far-field shape of a laser, quickly switch between the fundamental transverse mode of the single-lobe far-field and the single higher-order mode of the double-lobe far-field, so as to ensure both the high power output of the laser and the narrow linewidth characteristics of the laser.

[0005] In a first aspect, embodiments of the present invention provide a laser device, the laser device comprising a first waveguide, a second waveguide group, and a laser, wherein the second waveguide group includes a third waveguide and a fourth waveguide respectively disposed on both sides of the first waveguide; the laser includes a first ridge structure and a second ridge structure, wherein the width of the ridge strips of the first ridge structure and the second ridge structure is both smaller than the operating wavelength of the laser; applying a driving current to the first ridge structure causes the transverse mode corresponding to the first ridge strip of the first ridge structure to undergo lasing, and the lasing mode of the laser is a single-lobe far-field fundamental transverse mode; applying excitation to the first ridge structure and the... The second ridge structure is described, and the transverse mode corresponding to the second ridge of the first ridge structure is lased. The lasing mode of the laser is a single higher-order mode in the far field of a double-lobed structure. There is one first ridge and one second ridge. The angle between the third waveguide and the fourth waveguide is the same as the divergence angle of the laser emitted from the laser. When the lasing mode of the laser is a single higher-order mode in the far field of a double-lobed structure, the laser emitted from the laser is incident on the third waveguide and the fourth waveguide, respectively. When the lasing mode of the laser is a fundamental transverse mode in the far field of a single-lobed structure, the laser emitted from the laser is incident on the first waveguide.

[0006] In an optional embodiment of this application, the first ridge structure includes N ridge strips, and the second ridge structure includes N-1 ridge strips, where N≥2; the first ridge structure is configured to support N transverse molds, and the second ridge structure is configured to support N-1 transverse molds, with the transverse molds corresponding to the ridge strips; wherein, the N transverse molds of the first ridge structure include: TMM1 to TMM n The N-1 transverse modes of the second ridge structure are TMS1 to TMS2. n-1 , n=N.

[0007] In an optional embodiment of this application, a drive current is applied to the first ridge structure, and the transverse mode TMM of the first ridge structure... x+1 Transverse mode TMS of the second ridge structure x Coupling, 1≤x≤N-1, transverse mode TMM1 lasing of the first ridge structure.

[0008] In an optional embodiment of this application, a first excitation is applied to the first ridge structure and a second excitation is applied to the second ridge structure, wherein the transverse mode TMM of the first ridge structure is... y Coupled with the transverse mode TMSy of the second ridge structure, 1≤y≤N-1, and the transverse mode TMM of the first ridge structure. n The process involves lasing; the first excitation includes an electric current; the second excitation includes at least one of a driving current, optical excitation, and electron beam excitation.

[0009] In an optional embodiment of this application, the lasing mode of the laser is determined based on the width of each ridge, the interval between any two adjacent ridges, and the height of each ridge.

[0010] In an optional embodiment of this application, a second excitation is applied to the second ridge structure, the eigenvalue of the y-th transverse mode of the first ridge structure is equal to the eigenvalue of the y-th transverse mode of the second ridge structure, and the y-th transverse mode of the first ridge structure is coupled to the y-th transverse mode of the second ridge structure; wherein, 1≤y≤N-1.

[0011] In optional embodiments of this application, applying a second excitation to the second ridge structure includes: applying a driving current to the second ridge structure; applying a driving current to the second ridge structure includes: pre-determining a first relationship between the peak wavelength and the current; determining a second relationship between the effective refractive index of the material and the current based on the first relationship; determining a third relationship between the current and the temperature of the active region based on the second relationship; and determining the correspondence between the current and the change in eigenvalues ​​based on the third relationship.

[0012] In an optional embodiment of this application, the characteristic values ​​of N transverse modes of the first ridge structure are determined based on the diagonal elements of the Hamiltonian of the first ridge structure; and the characteristic values ​​of N-1 transverse modes of the second ridge structure are determined based on the diagonal elements of the Hamiltonian of the second ridge structure.

[0013] In an optional embodiment of this application, the Hamiltonian of the first ridge structure is constructed based on the width of each ridge of the first ridge structure, the interval between any two adjacent ridges of the first ridge structure, and the height of each ridge of the first ridge structure; wherein, the diagonal elements of the Hamiltonian of the first ridge structure represent the characteristic values ​​of a single ridge of the first ridge structure, the diagonal elements of the Hamiltonian of the second ridge structure represent the characteristic values ​​of a single ridge of the second ridge structure, and the off-diagonal elements of the Hamiltonian represent the coupling strength of adjacent ridges; a supersymmetric transformation is performed on the Hamiltonian of the first ridge structure to obtain the Hamiltonian of the second ridge structure; the width of each ridge of the second ridge structure, the interval between each ridge of the second ridge structure, and the height of each ridge of the second ridge structure are determined based on the Hamiltonian of the second ridge structure.

[0014] In an optional embodiment of this application, the laser is further provided with a grating structure, which is disposed above the active region of the laser.

[0015] The embodiments of the present invention bring the following beneficial effects:

[0016] This invention provides a laser device comprising a first waveguide, a second waveguide group, and a laser. The second waveguide group includes a third waveguide and a fourth waveguide respectively disposed on both sides of the first waveguide. The laser includes a first ridge structure and a second ridge structure, wherein the width of the ridge strips of the first ridge structure and the second ridge structure is smaller than the operating wavelength of the laser. A driving current is applied to the first ridge structure, causing lasing of the transverse mode corresponding to the first ridge strip of the first ridge structure. The lasing mode of the laser is a single-lobe far-field fundamental transverse mode. Excitation is applied to the first ridge structure and the second ridge structure... The laser has a two-ridge structure, where the transverse mode corresponding to the second ridge of the first ridge structure is emitted by lasing. The lasing mode of the laser is a single higher-order mode in the far field of a double-lobed structure. There is one first ridge and one second ridge. The angle between the third waveguide and the fourth waveguide is the same as the divergence angle of the laser emitted by the laser. When the lasing mode of the laser is a single higher-order mode in the far field of a double-lobed structure, the laser emitted by the laser is incident on the third waveguide and the fourth waveguide, respectively. When the lasing mode of the laser is a fundamental transverse mode in the far field of a single-lobed structure, the laser emitted by the laser is incident on the first waveguide.

[0017] In this method, by changing the driving current, the laser included in the laser device can switch between the fundamental transverse mode in the single-lobe far field and the single higher-order mode in the double-lobe far field, thereby controlling the far field shape of the laser and quickly switching between the single-lobe and double-lobe far fields. This ensures both the high power output of the laser and its narrow linewidth characteristics.

[0018] This laser device achieves automatic spatial routing of lasing modes by symmetrically arranging the third and fourth waveguides on both sides of the central first waveguide at an angle that matches the far-field double-lobe divergence angle of the laser's higher-order mode: when the laser is operating in a single-lobe basic transverse mode, the beam is coupled to the first waveguide; when operating in a double-lobe higher-order mode, the two lobes of the beam are coupled to the waveguides on both sides respectively.

[0019] This design can perform pattern recognition, separation, or filtering without additional control components, effectively improving system integration, stability, and beam quality monitoring capabilities.

[0020] Other features and advantages of this disclosure will be set forth in the following description, or some features and advantages may be inferred from the description or determined without doubt, or may be learned by practicing the techniques described above.

[0021] To make the above-mentioned objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 A schematic diagram of a laser structure provided in an embodiment of the present invention;

[0024] Figure 2 A schematic diagram of a laser's lasing mode provided in an embodiment of the present invention;

[0025] Figure 3 A schematic diagram illustrating the simulation results of a laser provided in an embodiment of the present invention;

[0026] Figure 4 A flowchart illustrating the method for constructing the first ridge structure and the second ridge structure of a laser according to an embodiment of the present invention;

[0027] Figure 5 A cross-sectional schematic diagram of a laser provided in an embodiment of the present invention;

[0028] Figure 6 This is a schematic diagram of the structure of a laser device provided in an embodiment of the present invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Currently, the far-field shape of traditional semiconductor lasers is usually determined by the device design, making it impossible to manually adjust the shape and divergence angle. To adjust the far-field shape of a laser, additional complex structures are required, such as high-order gratings, MEMS, and microlenses.

[0031] Based on this, the present invention provides a laser device including a laser, specifically including a high-power narrow-linewidth semiconductor laser including a far-field electrically tunable multi-ridge waveguide, which can adjust the far-field shape of the laser and quickly switch between single-lobe and double-lobe far-field, thus ensuring both high power output and narrow linewidth characteristics of the laser.

[0032] To facilitate understanding of this embodiment, a laser disclosed in this embodiment of the invention will first be described in detail.

[0033] This invention provides a laser, comprising a first ridge structure and a second ridge structure, wherein the width of the ridge strips of the first ridge structure and the second ridge structure is both smaller than the operating wavelength of the laser; when a driving current is applied to the first ridge structure, the first ridge strip of the first ridge structure undergoes lasing, and the lasing mode of the laser is a single-lobe far-field fundamental transverse mode; when an excitation is applied to the first ridge structure and the second ridge structure, the second ridge strip of the first ridge structure undergoes lasing, and the lasing mode of the laser is a double-lobe far-field single higher-order mode.

[0034] See Figure 1 The diagram shows a schematic of a laser structure, which includes a first ridge structure and a second ridge structure. The laser switches its lasing mode by adjusting the driving current. The lasing modes of the laser include single-lobe far-field fundamental transverse mode lasing and double-lobe far-field single higher-order mode lasing. When the driving current is applied to the first ridge structure, the lasing mode of the laser is single-lobe far-field fundamental transverse mode lasing. When the driving current is applied to the first ridge structure and the second ridge structure, the lasing mode of the laser is double-lobe far-field single higher-order mode lasing.

[0035] It should be understood that the first ridge structure of the laser described in this application includes N ridges, and the first ridge structure supports N transverse modes. The number of transverse modes is the same as the number of ridges. Each transverse mode is the result of the combined action of multiple ridges in the corresponding ridge structure. In this application, for ease of description, the N transverse modes are described in correspondence with the N ridges.

[0036] In one embodiment, the first ridge structure can be driven by DC, and the second ridge structure can be driven by pulses or AC to achieve periodic and rapid switching of the far-field shape and emission direction of the laser. When the second ridge structure is driven by pulses or AC, the driving period or frequency can be periodic or non-periodic.

[0037] This embodiment provides a laser, such as Figure 1 As shown, the laser has a multi-ridge structure (i.e., a first ridge structure and a second ridge structure). When a driving current is applied to the first ridge structure, the first ridge of the first ridge structure undergoes lasing, and the lasing mode of the laser is the fundamental transverse mode of the single-lobe far field. When excitation is applied to the first ridge structure and the second ridge structure, the second ridge of the first ridge structure undergoes lasing, and the lasing mode of the laser is the single higher-order mode of the double-lobe far field. In either case, the laser operates with only one transverse mode, thus ensuring high power output while also maintaining narrow linewidth characteristics.

[0038] In this embodiment, ion implantation can be performed first in the laser manufacturing process. Ion implantation is always performed on the first ridge structure, while ion implantation may or may not be performed on the second ridge structure.

[0039] Currently, common lasers generally use DC drive and typically have only one lasing mode, such as fundamental transverse mode lasing or a single higher-order mode lasing. The laser in this embodiment can switch its lasing mode by adjusting the drive current, i.e., switching between fundamental transverse mode lasing and a single higher-order mode lasing.

[0040] When a driving current is applied to the first ridge structure and no driving current is applied to the second ridge structure, the laser's lasing mode is fundamental transverse mode lasing; when a driving current is applied to both the first and second ridge structures, the laser's lasing mode is single higher-order mode lasing.

[0041] Therefore, in this embodiment, the lasing mode of the laser can be switched between fundamental transverse mode lasing and single higher-order mode lasing by adjusting the frequency of the driving current applied to the first ridge structure and the second ridge structure. Specifically, the first ridge structure and the second ridge structure can be simultaneously applied with the driving current.

[0042] For example, by using DC drive in the first ridge structure and AC or pulse drive in the second ridge structure, the laser can be controlled to periodically switch between basic transverse mode lasing and single higher-order mode lasing.

[0043] Alternatively, in practical applications, the laser's lasing mode can be switched according to actual needs. DC drive can be applied to the first ridge structure, and the pulse frequency of the second ridge structure can be manually set, allowing the laser to switch non-periodically between fundamental transverse mode lasing and single higher-order mode lasing as required by the specific scenario.

[0044] This invention provides a laser comprising a first ridge structure and a second ridge structure. The laser's lasing mode is switched by adjusting the driving current. The lasing modes include fundamental transverse mode lasing and a single higher-order mode lasing. When a driving current is applied to the first ridge structure, the laser's lasing mode is fundamental transverse mode lasing; when a driving current is applied to both the first and second ridge structures, the laser's lasing mode is a single higher-order mode lasing. This method allows for switching between fundamental transverse mode lasing and a single higher-order mode lasing by changing the driving current, thereby controlling the laser's far-field shape and rapidly switching between single-lobe and double-lobe far-field characteristics. This ensures both high power output and narrow linewidth characteristics of the laser.

[0045] In some embodiments, the fundamental transverse mode lasing includes: a single-lobe far-field fundamental transverse mode; the single higher-order mode lasing includes: a double-lobe far-field single higher-order mode.

[0046] In this embodiment, the laser can switch between the fundamental transverse mode lasing mode and a single higher-order mode lasing mode by changing the driving current. Since the fundamental transverse mode lasing includes a single-lobe far-field fundamental transverse mode, and the single higher-order mode lasing includes a double-lobe far-field single higher-order mode, this embodiment can achieve switching between the single-lobe far-field fundamental transverse mode and the double-lobe far-field single higher-order mode, thereby controlling the far-field shape and rapidly switching between the single-lobe and double-lobe far-field modes.

[0047] Based on the laser proposed in this application, when different excitations are applied to the first ridge structure and / or the second ridge structure, the lasing mode of the laser is only a single higher-order mode of the double-lobe far field or a basic transverse mode of the single-lobe far field, that is, only one ridge is lased in each mode; and there is no competition between modes, which can effectively ensure the high power output of the laser.

[0048] Based on the above embodiments, the specific implementation methods of basic transverse mode lasing and single higher-order mode lasing are described in detail.

[0049] In some embodiments, the first ridge structure includes N ridge strips, and the second ridge structure includes N-1 ridge strips, where N ≥ 2; the width of each ridge strip is smaller than the operating wavelength of the laser; the laser includes N transverse modes supported by the first ridge structure and N-1 transverse modes supported by the second ridge structure; wherein, the N transverse modes of the first ridge structure include: TMM1 to TMM n The N-1 transverse modes of the second ridge structure are TMS1 to TMS2. n-1 , n=N.

[0050] like Figure 1 As shown, the laser in this embodiment includes multiple ridges, which can be divided into two arrays (i.e., a first ridge structure and a second ridge structure). The first ridge structure contains N (N≥2) ridges, sequentially named: MR1, MR2…MR… n n=N; the second ridge structure contains N-1 ridges, namely: SR1, SR2...SR n-1 , n=N. Figure 1 The figure shows the case where N=5.

[0051] For the laser in this embodiment, the width of a single ridge needs to be sufficiently narrow, typically smaller than the laser's operating wavelength. Through this narrow-width ridge design, the laser can have 2N-1 transverse modes, including the N transverse modes of the first ridge structure (TMM1, TMM2...TMM...). nThe second ridge structure has N-1 transverse modes (TMS1, TMS2...TMS1). n-1 The transverse mold and the ridge are set in a one-to-one correspondence, that is, TMM1 corresponds to MR1, TMM2 corresponds to MR2, ... TMS1 corresponds to SR1, TMS... n-1 With SR n-1 Corresponding settings.

[0052] In some embodiments, the lasing mode of the laser can be determined based on the width of each ridge, the spacing between any two adjacent ridges, and the height of each ridge.

[0053] This embodiment allows the laser to have two lasing modes by adjusting the width of each ridge, the spacing between any two adjacent ridges, and the height of each ridge: a single-lobe far-field fundamental transverse mode and a double-lobe far-field single higher-order mode.

[0054] In one embodiment, if a driving current is applied to the first ridge structure but not to the second ridge structure, the laser's lasing mode is the fundamental transverse mode of the single-lobe far field.

[0055] In some embodiments, when a drive current is applied only to the first ridge structure, the transverse mode TMM of the first ridge structure... x+1 Transverse mode TMS of the second ridge structure x Coupling, 1≤x≤N-1, transverse mode TMM1 lasing of the first ridge structure. The transverse mode of the first ridge structure is the transverse mode supported by the first ridge structure, and the transverse mode of the second ridge structure is the transverse mode supported by the second ridge structure.

[0056] If a driving current is applied to the first ridge structure but not to the second ridge structure, the transverse modes TMM2, TMM3, TMM4...TMM of the first ridge structure... n The transverse modes TMS1, TMS2, TMS3...TMS of the second ridge structure are respectively connected to the transverse modes TMS1, TMS2, TMS3...TMS n-1 One-to-one correspondence and coupling. By introducing large losses into the second ridge structure, these one-to-one coupled modes can all generate large losses. The transverse mode TMM1 of the first ridge structure, which is the only one not coupled with other modes, has the smallest loss and can be lased, thus realizing the fundamental transverse mode of the single-lobe far field.

[0057] See also Figure 2 The diagram shows a lasing mode of a laser. Figure 2The diagram illustrates the correspondence between the two lasing modes when N=5. In the fundamental transverse mode of the single-lobe far field, the transverse modes TMM2, TMM3, TMM4, and TMM5 of the first ridge structure correspond one-to-one with and couple to the transverse modes TMS1, TMS2, TMS3, and TMM4 of the second ridge structure, respectively. These coupled modes exhibit significant losses. The transverse mode TMM1 of the first ridge structure does not couple to any transverse mode of the second ridge structure, thus minimizing losses and enabling lasing.

[0058] See also Figure 3 The diagram shown illustrates the simulation results of a laser. Figure 3 The simulation results for single-lobe far field and double-lobe far field are shown when N=5. The simulation results for the basic mode in which the driving current is applied to the first ridge structure and no driving current is applied to the second ridge structure are single-lobe far field.

[0059] In one embodiment, if a driving current is applied simultaneously to the first ridge structure and the second ridge structure, the laser's lasing mode is a single high-order mode in the double-lobed far field.

[0060] In some embodiments, when a drive current is applied simultaneously to the first ridge structure and the second ridge structure, the transverse mode TMM of the first ridge structure... y Transverse mode TMS of the second ridge structure y Coupling, 1≤y≤N-1, transverse mode TMM of the first ridge structure n Perform a lasing attack.

[0061] If driving currents are applied simultaneously to the first and second ridge structures, the internal temperature of the second ridge structure increases due to heat accumulation, causing a change in the effective refractive index of the modes contained within it. Therefore, the original mode correspondence between the first and second ridge structures changes. By adjusting the current in the second ridge structure, the transverse modes TMM1, TMM2, TMM3…TMM of the first ridge structure… n-1 The transverse modes TMS1, TMS2, TMS3...TMS of the second ridge structure are respectively connected to the transverse modes TMS1, TMS2, TMS3...TMS n-1 One-to-one correspondence and coupling of these modes results in significant losses. The only transverse mode TMM of the first ridge structure, which is not coupled with other modes, exhibits this characteristic. n This minimizes losses and thus enables lasing, allowing for the realization of a single high-order mode in the far field of a two-lobed structure.

[0062] like Figure 2 As shown, in the single higher-order mode of the two-lobed far field, the transverse modes TMM1, TMM2, TMM3, and TMM4 of the first ridge structure correspond one-to-one with and are coupled to the transverse modes TMS1, TMS2, TMS3, and TMS4 of the second ridge structure, respectively. These coupled modes have relatively large losses. The transverse mode TMM5 of the first ridge structure is not coupled to any transverse mode of the second ridge structure, thus having the minimum loss and thus lasing.

[0063] like Figure 3 As shown, the simulation results in the anti-phase mode with driving currents applied simultaneously to the first and second ridge structures are double-lobe far-field.

[0064] In some embodiments, a first excitation is applied to a first ridge structure and a second excitation is applied to a second ridge structure, wherein the transverse mode TMM of the first ridge structure is... y Transverse mode TMS of the second ridge structure y Coupling, 1≤y≤N-1, transverse mode TMM of the first ridge structure n Laser emission is performed; the first excitation includes a driving current; the second excitation includes at least one of driving current, optical excitation, and electron beam excitation.

[0065] In this embodiment, in addition to applying a driving current to the second ridge structure, other excitation methods such as optical excitation or electron beam excitation can also be performed on the second ridge structure. As long as the effective refractive index of the modes contained in the second ridge structure changes, the transverse mode TMM of the first ridge structure can also be affected. y Transverse mode TMS of the second ridge structure y Coupling (N-1≥y≥1), transverse mode TMM of the first ridge structure n Perform a lasing attack.

[0066] It should also be noted that when optical excitation is applied to the second ridge structure, the effective refractive index of the modes contained in the second ridge structure changes only slightly.

[0067] This invention provides a laser that can switch between a fundamental transverse mode in the single-lobe far field and a single higher-order mode in the double-lobe far field by changing the driving current, thereby controlling the far-field shape of the laser and rapidly switching between the single-lobe and double-lobe far fields. This ensures both high power output and narrow linewidth characteristics of the laser.

[0068] In this embodiment, by applying a driving current to the second ridge structure, the effective refractive index of the N-1 transverse modes of the second ridge structure is changed, thereby altering the coupling mode between the transverse modes of the first ridge structure and the second ridge structure. This allows the laser to switch between the fundamental transverse mode in the single-lobe far field and the single higher-order mode in the double-lobe far field.

[0069] Among them, when a driving current is applied to the first ridge structure, the transverse mode TMM of the first ridge structure x+1 Transverse mode TMS of the second ridge structure x Coupling, the transverse mode TMM1 of the first ridge structure is lased to realize the fundamental transverse mode of the single-lobe far field; when a driving current is applied to the first ridge structure and the second ridge structure, the transverse mode TMM of the first ridge structure... y Transverse mode TMS of the second ridge structure yCoupling, transverse mode TMM of the first ridge structure n Laser emission enables a single high-order mode in the far field of the two lobes.

[0070] Based on the above embodiments, the construction methods of the first and second ridge structures of the laser are described in detail. See also Figure 4 The diagram shows a method for constructing a first ridge structure and a second ridge structure of a laser, which includes the following steps:

[0071] Step S401: Construct the Hamiltonian of the first ridge structure based on the width of each ridge of the first ridge structure, the interval between any two adjacent ridges of the first ridge structure, and the height of each ridge of the first ridge structure.

[0072] In the Hamiltonian of the first ridge structure, the diagonal elements represent the eigenvalues ​​of individual ridges of the first ridge structure, the diagonal elements represent the eigenvalues ​​of individual ridges of the second ridge structure, and the off-diagonal elements represent the coupling strength of adjacent ridges.

[0073] For example, in this embodiment, it may be necessary to construct the Hamiltonian of the first ridge structure based on parameters such as the ridge width, ridge depth, and ridge spacing. :

[0074] ;

[0075] In the Hamiltonian, the diagonal elements represent the eigenvalues ​​of the transverse modes supported by a single ridge, while the off-diagonal elements represent the coupling strength between adjacent ridges.

[0076] Step S402: Perform a supersymmetric transformation on the Hamiltonian of the first ridge structure to obtain the Hamiltonian of the second ridge structure.

[0077] In this embodiment, the Hamiltonian of the second ridge structure can be obtained by performing a supersymmetric transformation on the Hamiltonian of the first ridge structure. .

[0078] Step S403: Determine the width of each ridge of the second ridge structure, the spacing between the individual ridges of the second ridge structure, and the height of each ridge of the second ridge structure based on the Hamiltonian of the second ridge structure.

[0079] In this embodiment, the Hamiltonian of the second ridge structure can be used to deduce parameters such as the ridge width, ridge depth, and ridge spacing of the second ridge structure, thereby obtaining the characteristic parameters of the complete array.

[0080] In some embodiments, the eigenvalues ​​of the N transverse modes of the first ridge structure can be determined based on the diagonal elements of the Hamiltonian of the first ridge structure; and the eigenvalues ​​of the N-1 transverse modes of the second ridge structure can be determined based on the diagonal elements of the Hamiltonian of the second ridge structure.

[0081] In some embodiments, if a driving current is applied to the second ridge structure, the characteristic values ​​of the N-1 transverse modes of the second ridge structure change; the characteristic value of the y-th transverse mode of the first ridge structure is equal to the characteristic value of the y-th transverse mode of the second ridge structure, and the y-th transverse mode of the first ridge structure is coupled to the y-th transverse mode of the second ridge structure; wherein, 1≤y≤N-1.

[0082] Using the construction method of the first and second ridge structures of the laser described above, the laser in this embodiment can have 2N-1 transverse modes, including N transverse modes of the first ridge structure (TMM1, TMM2...TMM1). n The second ridge structure has N-1 transverse modes (TMS1, TMS2...TMS1). n-1 The eigenvalues ​​of the N transverse modes of the first ridge structure are respectively , ... The eigenvalues ​​of the N-1 transverse modes of the second ridge structure are respectively , ... .

[0083] Furthermore, in order for the laser to have a single-lobe far-field fundamental transverse mode and a double-lobe far-field single higher-order mode, the characteristic parameters of the array (ridge width, ridge depth, ridge spacing, etc.) need to be further adjusted to meet the following conditions:

[0084] 1) Only the driving current is applied to the first ridge structure. The transverse mode TMM2 of the first ridge structure is connected to the transverse mode TMS1 of the second ridge structure, the transverse mode TMM3 of the first ridge structure is connected to the transverse mode TMS2 of the second ridge structure, and so on. The transverse mode TMM of the first ridge structure is connected to the transverse mode TMS2 of the second ridge structure. n Transverse mode TMS of the second ridge structure n-1 Each corresponds one-to-one and is coupled, that is , ... These one-to-one coupling modes all generate large losses.

[0085] The transverse mode TMM1 of the first ridge structure, which is the only one not coupled with other modes, has the minimum loss and thus lasing, corresponding to the basic transverse mode of the single-lobe far field.

[0086] 2) When driving current is applied to the first ridge structure and the second ridge structure at the same time, the effective refractive index of the modes contained in the second ridge structure changes, the characteristic values ​​of the N-1 transverse modes of the second ridge structure change, and the original mode correspondence between the first ridge structure and the second ridge structure also changes.

[0087] Among them, the eigenvalues ​​of the N-1 transverse modes of the second ridge structure are respectively , ... ,in, The change in characteristic value is caused by the thermal effect generated after applying electricity to the second ridge structure.

[0088] At this point, the transverse mold TMM1 of the first ridge structure and the transverse mold TMS1 of the second ridge structure, the transverse mold TMM2 of the first ridge structure and the transverse mold TMS2 of the second ridge structure... the transverse mold TMM of the first ridge structure n-1 Transverse mode TMS of the second ridge structure n-1 Each corresponds one-to-one and is coupled, that is , ... These one-to-one coupling modes all generate large losses.

[0089] The only transverse mode TMM of the first ridge structure not coupled with other modes n The loss is minimized, thus lasing occurs, corresponding to a single high-order mode in the far field of the two lobes.

[0090] In some embodiments, applying a second excitation to the second ridge structure includes: applying a driving current to the second ridge structure; and may also predetermine a first relationship between the peak wavelength and the current, determine a second relationship between the effective refractive index of the material and the current based on the first relationship, determine a third relationship between the current and the temperature of the active region based on the second relationship, and determine the correspondence between the current and the change in eigenvalues ​​based on the third relationship.

[0091] If the first and second ridge structures are successfully constructed and meet the conditions for both lasing modes, it can be obtained that when a specific current is applied to the second ridge structure... Afterwards, by changing the eigenvalue Δ of the second ridge structure, the laser will be able to switch from the fundamental transverse mode of the single-lobe far field to the single higher-order mode of the double-lobe far field.

[0092] The first relationship between peak wavelength and current change can be measured experimentally. In this embodiment, the second relationship between the effective refractive index of the material and current can be obtained through the first relationship between peak wavelength and current, thereby calculating the driving current required to be applied to the second ridge structure to obtain the target characteristic value change.

[0093] The eigenvalue change Δ of the second ridge structure and the driving current The corresponding relationship can be obtained by pre-characterizing the spectrum of a single transverse-mode and single longitudinal-mode laser with the same gain medium as the array laser under different currents. The first relationship between the peak wavelength and the current change can be obtained. Then, the relationship between the change in characteristic value Δ and the current change can be deduced through the second relationship between the effective refractive index of the material and the current, thereby calculating the driving current required for the array laser.

[0094] Specifically, a single transverse-mode and single longitudinal-mode laser with the same gain medium as the array laser, such as a distributed feedback (DFB) laser, can be used to adjust its different currents I. DFB The wavelength λ below DFB Measurements were performed to obtain the relationship λ. DFB = f(I DFB From Bragg's formula, we can obtain the second relationship between refractive index and current: 2d / n = f(I). DFB ), where d is the grating period and n is the refractive index.

[0095] The next step is to construct a thermal model of the distributed feedback (DFB) laser. Through thermal simulation, the relationship between the current and the active region temperature T can be calculated. DFB The third relation: I DFB = f(T DFB Thus, the relationship between the refractive index and the temperature of the active region is obtained: 2d / n = f(T) DFB This can be simplified to a linear relationship Δn. DFB = -k·ΔT DFB k is the temperature drift coefficient of the refractive index of this laser material.

[0096] The temperature change ΔT corresponding to the change in the subarray eigenvalues ​​Δ can be calculated from the characterized temperature drift coefficient. S That is, Δn DFB = k·ΔT S ,

[0097] The next step is to construct a thermal model of the array laser and obtain the sub-array current I through thermal simulation. S With respect to the active region temperature T of the laser S Change relationship I S = f(T S Through this relationship, and the temperature change ΔT S Finally, the current I required to achieve the dual-lobe operating mode of a single high-order mode was obtained. S .

[0098] In some embodiments, the laser is further provided with a grating structure, which is disposed above the active region of the laser.

[0099] The laser in this embodiment can also be configured with a grating structure, as can be seen in [reference needed]. Figure 5The diagram shown is a cross-sectional view of a laser. Figure 5 The image shows the transverse cross-section of the laser when N=5. The grating layer is a conventional first-order Bragg grating, located above the active region, enabling the laser to operate in a single longitudinal mode.

[0100] In summary, this invention presents an integrated multi-ridge waveguide device that is easy to manufacture and has a simple structure. By changing the driving current, wide-range, artificially controllable modulation of the far field can be achieved. Through the design of the multi-ridge waveguide structure, the laser can maintain single transverse mode output before and after switching in the far field, and a grating structure is introduced to ensure single longitudinal mode output, thereby achieving narrow linewidth output. Furthermore, the multi-ridge structure increases the effective area of ​​the device, thus increasing the output power.

[0101] This invention also provides a laser device, which is a device using the laser provided in the foregoing embodiments; the laser device includes: a first waveguide, a second waveguide group and the aforementioned laser, the second waveguide group includes a third waveguide and a fourth waveguide respectively disposed on both sides of the first waveguide; the included angle between the third waveguide and the fourth waveguide is determined with respect to the divergence angle of the laser emitted by the laser, such that when the lasing mode of the laser is a single higher-order mode in the double-lobed far field, the laser emitted by the laser is incident on the third waveguide and the fourth waveguide respectively; when the lasing mode of the laser is a fundamental transverse mode in the single-lobed far field, the laser emitted by the laser is incident on the first waveguide.

[0102] See Figure 6 The diagram shows a schematic of a laser device. When a driving current is applied to the first ridge structure of the laser but not to the second ridge structure, the laser's lasing mode is fundamental transverse mode lasing, and the laser device can emit laser light directly forward into the first waveguide. When a driving current is applied to the first and second ridge structures of the laser, the laser's lasing mode is single-lobe far-field fundamental transverse mode, and the laser device emits laser light to the left and right respectively into the third and fourth waveguides. The emission angle α of the laser device can be determined based on the laser's divergence angle.

[0103] Among them, the laser with fundamental transverse mode lasing is used in high-precision machining, scientific research and communication, while the laser with single-lobe far-field fundamental transverse mode is used in shallow welding, material surface treatment and optics. Alternatively, when both fundamental transverse mode lasing and a single higher-order mode are required simultaneously, the laser proposed in this application can act as a switch to achieve rapid switching between the two modes, thus improving production efficiency to suit practical scenarios.

[0104] Therefore, in this embodiment, by controlling the frequency of the driving current applied to the first and second ridge structures of the laser, the laser device can be periodically or non-periodically controlled to emit lasers directly in front, or to emit lasers to the left and right respectively, thereby adjusting the far-field shape of the laser and quickly switching between single-lobe and double-lobe far-field, which can ensure both the high power output of the laser and the narrow linewidth characteristics of the laser.

[0105] To achieve smooth switching between single-lobe and double-lobe far-field modes in a laser, precise, continuous, and stable control of the excitation states of the two ridge waveguide arrays is required, taking into account factors such as optical coupling characteristics, thermal effects, and mode stability between the waveguides. "Smooth switching" not only refers to the continuous evolution of the far-field intensity angular distribution from a single main lobe to a double main lobe, but also requires no mode jumps, stable output power, controllable angular distribution, and good repeatability and predictability during the switching process. This is especially crucial for photonic integrated chips, where rapid, convenient, and smooth control of the waveguide conduction is essential.

[0106] In one embodiment, the first and second ridge structures are each equipped with independent current drive sources that are high-precision, low-noise, and continuously adjustable, avoiding the use of simple binary (on / off) control methods. By slowly increasing the injected current of one ridge structure from zero to above a threshold while maintaining the other ridge structure at a constant operating point slightly above the threshold, the far-field radiation distribution can gradually transition from a single lobe to an asymmetric double lobe, ultimately forming a symmetric double lobe. This asymmetric intermediate state constitutes a physically continuous evolution path and is the key mechanism for achieving smooth switching.

[0107] In one implementation, to suppress mode instability caused by gain competition, if the first and second ridge structures are completely decoupled, their independent lasing can easily lead to mutual mode suppression, causing abrupt changes in the far field. Therefore, the laser introduces moderate evanescent field coupling, and by appropriately setting the waveguide spacing (typically 2–5 μm), the two form a weakly coupled supermode structure. This structure retains the ability to form a double-lobed far field while mitigating severe mode competition.

[0108] In one implementation, thermal effects are also a significant factor affecting switching smoothness. Localized temperature rise caused by current injection alters the effective refractive index of the waveguide, leading to far-field main lobe angle drift and even mode instability. To reduce thermal load, this application employs pulsed current driving to decrease average power consumption; furthermore, a temperature sensing unit is integrated on the chip and combined with a closed-loop feedback system to dynamically compensate for thermally induced phase changes. In addition, selecting a substrate material with high thermal conductivity (such as aluminum nitride or diamond) also helps improve overall thermal management performance.

[0109] In one implementation, an active phase modulation mechanism is further introduced for applications requiring higher performance. Electro-optic or thermo-optic phase shifters are integrated at the back end of each waveguide. By adjusting the relative phase difference between the two channels, the far-field interference pattern is precisely controlled: when the phase difference is 0, the far field tends to concentrate towards the center, exhibiting a single-lobe-like characteristic; when the phase difference is π, a typical double-lobe structure is formed; the intermediate phase corresponds to a continuously adjustable transition mode to suit advanced application scenarios such as high-precision beam scanning.

[0110] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the laser device described above can be referred to the corresponding process in the foregoing embodiments, and will not be repeated here.

[0111] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0112] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0113] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A laser device, characterized in that, The laser device includes a first waveguide, a second waveguide group, and a laser. The second waveguide group includes a third waveguide and a fourth waveguide respectively disposed on both sides of the first waveguide. The laser includes a first ridge structure and a second ridge structure, wherein the width of the ridge strips of the first ridge structure and the ridge strips of the second ridge structure is smaller than the operating wavelength of the laser. When a driving current is applied to the first ridge structure, the transverse mode corresponding to the first ridge of the first ridge structure is lased, and the lasing mode of the laser is the fundamental transverse mode of the single-lobe far field. Excitation is applied to the first ridge structure and the second ridge structure, and the transverse mode corresponding to the second ridge of the first ridge structure is lased. The lasing mode of the laser is a single high-order mode in the far field of a double lobe. The number of the first ridge and the second ridge is one. The angle between the third waveguide and the fourth waveguide is the same as the divergence angle of the laser emitted from the laser. When the laser's lasing mode is a single higher-order mode in the double-lobed far field, the laser emitted from the laser is incident on the third waveguide and the fourth waveguide, respectively. When the laser's lasing mode is a fundamental transverse mode in the single-lobed far field, the laser emitted from the laser is incident on the first waveguide. The first ridge structure includes N ridge strips, and the second ridge structure includes N-1 ridge strips, where N ≥ 2; the first ridge structure is configured to support N transverse molds, and the second ridge structure is configured to support N-1 transverse molds, wherein the transverse molds are correspondingly arranged with respect to the ridge strips; wherein the N transverse molds of the first ridge structure include: TMM1 to TMM n The N-1 transverse modes of the second ridge structure are TMS1 to TMS2. n-1 , n=N; A drive current is applied to the first ridge structure, and the transverse mode TMM of the first ridge structure... x+1 With the transverse mode TMS of the second ridge structure x Coupled, 1≤x≤N-1, transverse mode TMM1 lasing of the first ridge structure; Applying a first excitation to the first ridge structure and applying a second excitation to the second ridge structure, the transverse mode TMM of the first ridge structure y With the transverse mode TMS of the second ridge structure y Coupling, 1≤y≤N-1, the transverse mode TMM of the first ridge structure n Laser emission is performed; the first excitation includes a driving current; the second excitation includes at least one of driving current, optical excitation, and electron beam excitation.

2. The laser device according to claim 1, characterized in that, The lasing mode of the laser is determined based on the width of each ridge, the interval between any two adjacent ridges, and the height of each ridge.

3. The laser device according to claim 1 or 2, characterized in that, A second excitation is applied to the second ridge structure, the eigenvalue of the y-th transverse mode of the first ridge structure is equal to the eigenvalue of the y-th transverse mode of the second ridge structure, and the y-th transverse mode of the first ridge structure is coupled to the y-th transverse mode of the second ridge structure; wherein, 1≤y≤N-1.

4. The laser device according to claim 3, characterized in that, Applying the second excitation to the second ridge structure includes: applying a driving current to the second ridge structure; Applying a driving current to the second ridge structure includes: Predetermine the initial relationship between the peak wavelength and the current; Based on the first relationship, a second relationship between the effective refractive index of the material and the current is determined; Based on the second relationship, a third relationship between current and active region temperature is determined; The correspondence between current and eigenvalue changes is determined based on the third relationship.

5. The laser device according to claim 3, characterized in that, The eigenvalues ​​of the N transverse modes of the first ridge structure are determined based on the diagonal elements in the Hamiltonian of the first ridge structure. The eigenvalues ​​of the N-1 transverse modes of the second ridge structure are determined based on the diagonal elements of the Hamiltonian of the second ridge structure.

6. The laser device according to claim 5, characterized in that, The Hamiltonian of the first ridge structure is constructed based on the width of each ridge of the first ridge structure, the interval between any two adjacent ridges of the first ridge structure, and the height of each ridge of the first ridge structure; wherein, the diagonal elements of the Hamiltonian of the first ridge structure represent the characteristic values ​​of a single ridge of the first ridge structure, the diagonal elements of the Hamiltonian of the second ridge structure represent the characteristic values ​​of a single ridge of the second ridge structure, and the off-diagonal elements of the Hamiltonian represent the coupling strength of adjacent ridges. A supersymmetric transformation is performed on the Hamiltonian of the first ridge structure to obtain the Hamiltonian of the second ridge structure; The width of each ridge of the second ridge structure, the spacing between the individual ridges of the second ridge structure, and the height of each ridge of the second ridge structure are determined based on the Hamiltonian of the second ridge structure.

7. The laser device according to any one of claims 1-2 or 4-6, characterized in that, The laser also has a grating structure, which is disposed above the active region of the laser.

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