Laser, laser array and optical device

Abstract

The present application relates to the technical field of optics, and in particular to a laser, a laser array and an optical device. The laser comprises an epitaxial structure and a phase control component. A grating layer in the epitaxial structure comprises a first grating area, a second grating area and a third grating area which are sequentially arranged in a cavity length direction of the laser. A first grating period corresponding to the second grating area is greater than a second grating period corresponding to both the first grating area and the third grating area. In the process of the laser emitting light waves, the phase control component is used to control the intracavity phase of the laser by changing the refractive index of the second grating area, thereby controlling the wavelength of the light waves. The laser exhibits a high frequency sweeping speed, strong applicability, and high practicality.

Description

Laser, laser array and optical device

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on January 29, 2024, with application number 202410128417.X and application name “A Laser, Laser Array and Optical Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of optical technology, and in particular to a laser, a laser array, and an optical device. Background Art

[0003] With the continuous advancement of optical technology, the application scenarios of continuously tunable wavelength lasers are constantly expanding. For example, they can be used in coherent optical communication systems, frequency modulated continuous wave (FMCW) radar, and wavelength division multiplexer (WDM) systems. As one of the core components, the operating state of a continuously tunable wavelength laser directly affects the overall performance of the device or system in which it is installed. Therefore, the performance of continuously tunable wavelength lasers has become a focus of attention.

[0004] Distributed feedback (DFB) lasers, which enable continuously tunable wavelengths, are widely used due to their low cost, simple structure, and low process complexity. Existing DFB lasers typically achieve continuous frequency sweeping by adjusting their internal thermoelectric cooler (TEC) and current. However, the TEC's long response time significantly limits the frequency sweeping speed of existing DFB lasers, severely impacting their applicability and practicality. Summary of the Invention

[0005] To address the above issues, this application provides a laser, laser array, and optical device. The laser has a fast sweep speed and strong applicability and practicality. This laser can address the significant sweep speed limitations of existing DFB lasers.

[0006] The present application is introduced below from multiple aspects. It is easy to understand that the implementation methods of the following multiple aspects can refer to each other.

[0007] In a first aspect, the present application provides a laser. The laser comprises an epitaxial structure and a phase control component. The grating layer in the epitaxial structure comprises a first grating region, a second grating region, and a third grating region arranged sequentially along the laser cavity length. The first grating period corresponding to the second grating region is greater than the second grating period corresponding to the first and third grating regions. During the process of emitting light waves from the laser, the phase control component is used to control the intra-cavity phase of the laser by changing the refractive index of the second grating region, thereby controlling the wavelength of the light waves.

[0008] In the above implementation, the phase control component in the laser can be used to control the intracavity phase of the laser by changing the refractive index of the second grating region, thereby further changing the wavelength of the light wave emitted by the laser. Since the response time of changing the lasing wavelength by controlling the refractive index of the grating region to control the intracavity phase of the laser is very short, and continuous control of the lasing wavelength can be achieved, the laser provided in this application can achieve rapid and continuous control of the lasing wavelength through the phase control component, so its sweeping speed is very fast when implementing the sweeping function. Therefore, the solution provided by this application can solve the problem of slow sweeping speed of existing DFB lasers and improve the applicability and practicality of DFB lasers.

[0009] In conjunction with the first aspect, in some possible implementations, the laser includes a first electrode layer, a second electrode layer, and a third electrode layer disposed on a first surface of the epitaxial structure, and a fourth electrode layer disposed on a second surface of the epitaxial structure. The first surface is located on the side of the grating layer facing away from the substrate layer in the epitaxial structure, and the second surface is the surface of the substrate layer facing away from the grating layer. The first electrode layer and the first grating region are disposed opposite each other in the epitaxial growth direction of the epitaxial structure. The second electrode layer and the second grating region are disposed opposite each other in the epitaxial growth direction, and the third electrode layer and the third grating region are disposed opposite each other in the epitaxial growth direction. A first groove is disposed between the first electrode layer and the second electrode layer, and a second groove is disposed between the second electrode layer and the third electrode layer. The first groove is used to achieve electrical isolation between the first electrode layer and the second electrode layer, and the second groove is used to achieve electrical isolation between the second electrode layer and the third electrode layer. The phase control component includes a second electrode and a fourth electrode, and the refractive index of the second grating region is controlled by an excitation electrical signal input to the second electrode layer and the fourth electrode layer.

[0010] In this implementation, the second and fourth electrode layers serve as phase control components, controlling the refractive index of the second grating region through electrical injection. Grooves are also designed between the electrode layers for electrical isolation. This simple and reliable implementation reduces laser cost while ensuring stable performance.

[0011] In combination with the first aspect, in some possible implementations, the depths of the first groove and the second groove in the epitaxial growth direction are equal to or greater than the thickness of the cover layer, and less than the sum of the thicknesses of the cover layer and the first cladding layer in contact with the cover side in the epitaxial structure.

[0012] In the above implementation, etching the first groove and the second groove through the cover layer can ensure that the first electrode layer, the second electrode layer and the third electrode layer are all insulated, thereby effectively ensuring that there is no short circuit between the first electrode layer, the second electrode layer and the third electrode layer.

[0013] In conjunction with the first aspect, in some possible implementations, the epitaxial structure further includes a ridge waveguide structure. The ridge waveguide structure includes a first ridge waveguide region, a second ridge waveguide region, and a third ridge waveguide region, which are arranged sequentially in the cavity length direction and are divided by a first groove and a second groove. The first surface includes at least the surfaces of the first ridge waveguide region, the second ridge waveguide region, and the third ridge waveguide region facing away from the grating layer, as well as the mesas on both sides of the ridge waveguide structure. The second electrode layer is disposed on the surface of the second ridge waveguide region facing away from the grating layer, or the first portion of the second electrode layer is disposed on the surface of the second ridge waveguide region facing away from the grating layer, and the second portion of the second electrode layer, excluding the first portion, is disposed on the mesas on both sides of the second ridge waveguide region.

[0014] In conjunction with the first aspect, in some possible implementations, the phase control component includes a heating component, the heating component being disposed on a first surface of the epitaxial structure, the heating component being proximate to the second grating region, the first surface being located on a side of the grating layer facing away from the substrate layer of the epitaxial structure. The heating component is configured to heat the second grating region in response to an applied excitation electrical signal, thereby changing the refractive index of the second grating region.

[0015] In the above implementation, the heating component is used as the phase control component, thereby controlling the refractive index of the second grating region by electrical heating. This implementation is simple and reliable, and can reduce the cost of the laser.

[0016] In conjunction with the first aspect, in some possible implementations, the length of the heating component in the cavity length direction is less than or equal to the length of the second grating region in the cavity length direction. Here, designing the length of the heating component in the cavity length direction to be less than the length of the second grating region in the cavity length direction can reduce thermal crosstalk with other regions of the laser and mitigate power fluctuations caused by heating.

[0017] In conjunction with the first aspect, in some possible implementations, the epitaxial structure further includes a third groove and a fourth groove, wherein the third groove, the heating element, and the fourth groove are sequentially arranged along the cavity length direction. The third groove is configured to prevent heat from the heating element from being transferred to the first grating region, and the fourth groove is configured to prevent heat from the heating element from being transferred to the third grating region.

[0018] In the above implementation, a third groove and a fourth groove are provided on both sides of the heating component to achieve thermal isolation of the first grating region and the third grating region. This not only improves the heating efficiency of the heating component on the second grating region, but also reduces thermal crosstalk in other areas of the laser and reduces power fluctuations caused by heating.

[0019] In combination with the first aspect, in some possible implementations, the epitaxial structure also includes a ridge waveguide structure, the first surface includes a third surface of the ridge waveguide structure facing away from the grating layer and table surfaces on both sides of the ridge waveguide, the heating component is arranged on a target table surface on either side of the ridge waveguide structure, and the third groove and the fourth groove and the second groove are located in the area where the target table surface is located.

[0020] In combination with the first aspect, in some possible implementations, the depths of the third groove and the fourth groove in the epitaxial growth direction of the epitaxial structure are both smaller than the thickness of the first cladding layer in the epitaxial structure that is in contact with the cover layer.

[0021] In combination with the first aspect, in some possible implementations, the heating component includes a thin film metal resistor and a first electrode and a second electrode respectively connected to the two ends of the thin film metal resistor, the long axis direction of the thin film metal resistor is parallel to the cavity length direction of the laser, and the thin film metal resistor heats the second grating area under the action of the excitation electrical signal connected to the first electrode and the second electrode.

[0022] In the above implementation, a thin film metal resistor is used as a heating component. The solution is simple and easy to implement, which can reduce the cost of the laser.

[0023] In combination with the first aspect, in some possible implementations, the initial phase of the laser is determined by the first grating period, the second grating period, and a first length of the second grating region in the cavity length direction of the laser.

[0024] In conjunction with the first aspect, in some possible implementations, the initial phase of the laser is a preset target phase. The difference between a first phase value corresponding to a bandgap of a grating structure in the epitaxial structure and a second phase value corresponding to a transmission bandwidth of the grating structure is less than or equal to a preset difference, and the second phase value is a phase value corresponding to an upper limit or a lower limit of the transmission bandwidth of the grating structure.

[0025] For the laser provided in the present application, the initial phase can be made to reach a preset target phase by designing the values ​​of the first grating period, the second grating period, and the first length, so that the initial phase value corresponding to the band gap of the grating structure in the epitaxial structure can be as close as possible to the phase value corresponding to the upper limit or lower limit of the transmission bandwidth of the grating structure. Since the band gap of the grating structure will continuously move with a period of 2π within the transmission bandwidth of the grating structure, if the design makes the initial phase value corresponding to the band gap of the grating structure as close as possible to the phase value corresponding to the upper limit or lower limit of the transmission bandwidth of the grating structure, the movable range of the band gap of the grating structure can be made larger. In this way, when the laser realizes the continuous frequency sweep function, its frequency sweep range will become larger, and the frequency sweep bandwidth of the laser can be improved.

[0026] In conjunction with the first aspect, in some possible implementations, the initial phase of the laser and the first grating period, the second grating period, and the first length satisfy the following formula:

[0027] Wherein, P is the initial phase, L is the first length, S1 is the first grating period, and S2 is the second grating period.

[0028] In combination with the first aspect, in some possible implementations, the cavity surfaces of the laser in the cavity length direction are respectively coated with an anti-reflection film and a high-reflection film, and the ratio of the first length to the second length of the grating layer in the cavity length direction is greater than or equal to 0.3 and less than or equal to 0.4.

[0029] In combination with the first aspect, in some possible implementations, the grating layer includes a first sub-grating layer and a second sub-grating layer arranged sequentially in the epitaxial growth direction of the epitaxial structure, the first sub-grating layer adopts N-type doping, and the second sub-grating layer adopts P-type doping.

[0030] In the above implementation, the grating layer adopts a complex coupled grating structure, which can introduce a negative feedback effect and reduce the effective linewidth enhancement factor, thereby facilitating the realization of a narrower linewidth output and lower relative intensity noise of the laser.

[0031] In combination with the first aspect, in some possible implementations, the active layer in the epitaxial structure is provided with a first cavity, the first cavity penetrates the active layer in the epitaxial growth direction of the epitaxial structure, the first cavity and the second grating region are arranged opposite to each other in the epitaxial growth direction, and the first cavity is filled with a bulk material waveguide.

[0032] In combination with the first aspect, in some possible implementations, a first effective refractive index of the bulk waveguide matches a second effective refractive index of a portion of the active layer located on both sides of the first cavity.

[0033] In conjunction with the first aspect, in some possible implementations, the epitaxial structure further includes a multi-quantum well layer and a substrate layer, and the grating layer is disposed on a side of the multi-quantum well layer facing away from the substrate layer, or the grating layer is disposed between the multi-quantum well layer and the substrate layer. In the above implementation, the grating layer is disposed between the multi-quantum well (MQW) layer and the substrate layer, i.e., the grating layer is prepared as a bottom grating, which can optimize the square distribution and thus reduce the internal loss of the laser.

[0034] In combination with the first aspect, in some possible implementations, the laser is a distributed feedback DFB laser.

[0035] In a second aspect, the present application provides a laser array. The laser array may include at least two lasers 100 provided by the present application. In actual operation, the laser array simultaneously emits at least two light waves through the two lasers.

[0036] In a third aspect, the present application provides an optical device. The optical device may include a laser provided by any possible implementation of the first aspect or a laser array provided by the second aspect. In actual operation, the laser or the laser array provided above is used to provide the required light waves for the optical device.

[0037] With reference to the first aspect, in some possible implementations, the optical device may be an optical line terminal (OLT) or an optical network unit (ONU).

[0038] In summary, the laser provided in this application has a fast frequency sweep speed and is highly applicable and practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG1 is a schematic diagram of the structure of a laser provided by the present application;

[0040] FIG2 is another structural schematic diagram of a laser provided by the present application;

[0041] FIG3 is another structural schematic diagram of a laser provided by the present application;

[0042] FIG4 is another structural schematic diagram of a laser provided by the present application;

[0043] FIG5 is another structural schematic diagram of a laser provided by the present application;

[0044] FIG6 is another structural diagram of a laser provided by the present application;

[0045] FIG7 is another structural schematic diagram of a laser provided by the present application;

[0046] FIG8 is another structural schematic diagram of a laser provided by the present application;

[0047] FIG9 is a schematic structural diagram of a grating layer provided by the present application;

[0048] FIG10 is another structural schematic diagram of a laser provided by the present application;

[0049] FIG11 is another structural schematic diagram of a laser provided by the present application;

[0050] FIG12 is a schematic structural diagram of a laser array provided by the present application;

[0051] FIG13 is a schematic structural diagram of an optical device provided in this application. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings provided in the embodiments of the present application.

[0053] In this application, "at least one" means one or more, and "more" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. In the text description of this application, the character " / " generally indicates that the previous and next associated objects are in an "or" relationship; in the formula of this application, the character " / " indicates that the previous and next associated objects are in a "division" relationship. "Including at least one of A, B and C" can mean: including A; including B; including C; including A and B; including A and C; including B and C; including A, B and C.

[0054] Existing DFB lasers typically achieve continuous frequency sweeping by adjusting their internal TEC and current. However, the long response time of the TEC significantly limits the frequency sweeping speed of existing DFB lasers, severely impacting their applicability and practicality.

[0055] Therefore, the technical problem to be solved by this application is: how to increase the frequency sweep speed of the DFB laser, thereby improving the applicability and practicality of the DFB laser.

[0056] Please refer to Figure 1, which is a schematic diagram of a laser structure provided by the present application. It should be understood that Figure 1 is a front view of the laser 100. As shown in Figure 1, the laser 100 may include an epitaxial structure 11 and a phase control component 13. The epitaxial structure 11 includes a grating layer 110. The grating layer 110 includes a first grating region 1101, a second grating region 1102, and a third grating region 1103 arranged in sequence along the cavity length direction of the laser 100 (here, assumed to be direction Y). The first grating period corresponding to the second grating region 1102 (i.e., the grating period S1 shown in Figure 1) is greater than the second grating period corresponding to the first grating region 1101 and the third grating region 1103 (i.e., the grating period S2 shown in Figure 1). In other words, the grating layer 110 can be composed of three uniform gratings arranged in sequence along the cavity length direction Y, and the grating period of the uniform grating arranged in the middle is greater than the grating periods of the remaining two gratings. It should be understood that the cavity length direction Y of the laser 100 is perpendicular to the epitaxial growth direction (here assumed to be direction X) of the epitaxial structure 11 . The phase control component 13 is disposed near the second grating region 1102 .

[0057] In actual operation, when the laser 100 emits a light wave, the phase control component 13 is used to control the intracavity phase of the laser 100 by changing the refractive index of the second grating region 1102, thereby controlling the wavelength of the light wave emitted by the laser 100 (which can also be understood as the lasing wavelength of the laser 100). In particular, when the laser 100 needs to perform continuous frequency sweeping, the phase control component 13 can control the continuous change of the intracavity phase of the laser 100 by changing the refractive index of the second grating region 1102, thereby causing the wavelength of the light wave emitted by the laser 100 to continuously change, enabling the laser 100 to achieve a continuous frequency sweeping function.

[0058] It should be explained that the laser 100 may also include a filling layer 111, which is in contact with the grating layer 110 and fills the gaps between the gratings in the grating layer. The filling layer 111 and the grating layer 110 together constitute the grating structure in the epitaxial structure 11 (the grating structure can also be understood as a Bragg grating in the epitaxial structure 11). The structural design of the grating layer 110 will introduce a band gap in the transmission bandwidth of the grating structure. Generally, this band gap refers to the position where the transmittance is 1 or close to 1 within the transmission bandwidth of the grating structure. For the laser 100, the structural design of the grating layer 110 will break the degeneracy of its mode, so that the lasing wavelength of the laser 100 (that is, the wavelength of its emitted light wave) is located at the position of the above-mentioned band gap. If the laser 100 changes the refractive index of the second grating region 1102 in the grating layer 110 through the phase control component 13, the position of the introduced bandgap can be changed (which will also cause the intracavity phase of the laser 100 to change), thereby causing the lasing wavelength of the laser 100 to change accordingly. It should be noted that the bandgap will continuously move with a period of 2π within the transmission bandwidth of the grating structure. Therefore, the laser 100 continuously controls the refractive index of the second grating region 1102 to continuously change the lasing wavelength of the laser 100, thereby enabling the laser 100 to achieve a continuous frequency sweep function. Furthermore, because the bandgap will move with a period of 2π within the transmission bandwidth of the grating structure, the continuous frequency sweep trajectory of the laser 100 can reach a maximum range without exceeding the transmission bandwidth of the grating structure.

[0059] It should also be noted that the epitaxial structure 11 provided in the present application can be understood as the laser body of the laser 100 , and can also be understood as the device structure of the laser 100 .

[0060] In the above implementation, the phase control component 13 in the laser 100 can be used to control the intracavity phase of the laser 100 by changing the refractive index of the second grating region 1102, thereby further changing the wavelength of the light wave emitted by the laser 100. Since the response time of changing the lasing wavelength by controlling the refractive index of the grating region to control the intracavity phase of the laser is very short, and continuous control of the lasing wavelength can be achieved, the laser 100 provided in the present application can achieve rapid and continuous control of the lasing wavelength through the phase control component 13, so its sweeping speed when implementing the sweeping function is very fast. Therefore, the solution provided by the present application can solve the problem of slow sweeping speed of existing DFB lasers and improve the applicability and practicality of DFB lasers.

[0061] In some optional implementations, please refer to Figure 2, which is another structural schematic diagram of a laser provided in this application. As shown in Figure 2, the above-mentioned laser 100 may include a first electrode layer 131, a second electrode layer 132, and a third electrode layer 133 arranged on the first surface 1131 of the epitaxial structure 11. For ease of understanding, Figure 2 shows the first electrode layer 131, the second electrode layer 132, and the third electrode layer 133 separated from the first surface 1131. In actual implementation, the first electrode layer 131, the second electrode layer 132, and the third electrode layer 133 are in contact with the first surface 1131. The laser 100 may also include a fourth electrode layer 134 arranged on the second surface 1132 of the epitaxial structure 11. Similarly, for ease of understanding, Figure 2 shows the fourth electrode layer 134 separated from the second surface 1132. In actual implementation, the fourth electrode layer 134 is in contact with the second surface 1132. As shown in FIG2 , the first surface 1131 is located on the side of the grating layer 110 facing away from the substrate layer 112 in the epitaxial structure 11. In other words, the first surface 1131 is the surface of the epitaxial structure 11 on the side of the grating layer 110 facing away from the substrate layer 112. The second surface 1132 is the surface of the substrate layer 112 facing away from the grating layer 110. In other words, the second surface 1132 is the surface of the epitaxial structure 11 on the side of the substrate layer 112 facing away from the grating layer 110.

[0062] The first electrode layer 131 and the first grating region 1101 are disposed opposite each other in the epitaxial growth direction X. In other words, in a direction opposite to the epitaxial growth direction X, the projections of the first electrode layer 131 and the first grating region 1101 on the substrate layer 112 partially or completely overlap. The second electrode layer 132 and the second grating region 1102 are disposed opposite each other in the epitaxial growth direction X. In other words, in a direction opposite to the epitaxial growth direction X, the projections of the second electrode layer 132 and the second grating region 1102 on the substrate layer 112 partially or completely overlap. The third electrode layer 133 and the third grating region 1103 are disposed opposite each other in the epitaxial growth direction X. In other words, in a direction opposite to the epitaxial growth direction X, the projections of the third electrode layer 133 and the third grating region 1103 on the substrate layer 112 partially or completely overlap.

[0063] Furthermore, a first groove 1141 is provided between the first electrode layer 131 and the second electrode layer 132, and a second groove 1142 is provided between the second electrode layer 132 and the third electrode layer 133. The first groove 1141 is used to achieve electrical isolation between the first electrode layer 131 and the second electrode layer 132, so that there is no electrical connection between the first electrode layer 131 and the second electrode layer 132. It can also be understood that the first electrode layer 131, the second electrode layer 132, and the third electrode layer 133 are three electrically unconnected regions formed on the same electrode layer after etching the first groove 1141 and the second groove 1142.

[0064] It should be noted that, in the presence of the first groove 1141 and the second groove 1142, the cover layer 115 is also divided into three different regions arranged in sequence along the cavity length direction Y, which are respectively named as the first cover region, the second cover region, and the third cover region. The first surface 1131 mentioned above can include the surfaces of the first cover region, the second cover region, and the third cover region facing away from the grating layer 110. The first electrode layer 131 can be disposed on the surface of the first cover region facing away from the grating layer 110, the second electrode layer 132 can be disposed on the surface of the second cover region facing away from the grating layer 110, and the third electrode layer 133 can be disposed on the surface of the third cover region facing away from the grating layer 110.

[0065] In actual use, the second groove 1142 is used to achieve electrical isolation between the third electrode layer 133 and the second electrode layer 132, so that there is no electrical connection between the third electrode layer 133 and the second electrode layer 132. The design of the first groove 1141 and the second groove 1142 can prevent short circuits among the first electrode layer 131, the second electrode layer 132, and the third electrode layer 133, thereby ensuring the operating stability of the laser 100.

[0066] In addition, the phase control component 13 mentioned above can include the above-mentioned second electrode layer 132 and fourth electrode layer 134. In actual operation, the second electrode layer 132 and the fourth electrode layer 134 are electrically connected and can be used to access the excitation electrical signal (for the convenience of distinction, the first excitation electrical signal will be used instead of the expression below). The refractive index of the above-mentioned second grating region 1102 can be controlled by the first excitation electrical signal. Specifically, the refractive index of the second grating region 1102 corresponds to the current amplitude or voltage amplitude of the first excitation electrical signal, and will change with the change of the current amplitude or voltage amplitude of the first excitation electrical signal. In other words, the laser 100 can control the refractive index of the second grating region 1102 by controlling the current amplitude or voltage amplitude of the first excitation electrical signal accessed by the phase control component 13, thereby achieving the purpose of controlling its lasing wavelength.

[0067] Optionally, the minimum distance between the first groove 1141 and the second groove 1142 in the cavity length direction Y may be less than or equal to the first length of the second grating region 1102 in the cavity length direction Y.

[0068] It should also be noted that, in actual implementation, the first electrode layer 131 and the fourth electrode layer 134 are also electrically connected and can be used to receive another excitation electrical signal (for ease of distinction, referred to as the second excitation electrical signal below). The second excitation electrical signal is used to control the refractive index of the first grating region 1101. The third electrode layer 133 and the fourth electrode layer 134 are also electrically connected and can be used to receive another excitation electrical signal (for ease of distinction, referred to as the third excitation electrical signal below). The third excitation electrical signal can be used to control the refractive index of the third grating region 1103. Optionally, there may be an electrical connection between the first electrode layer 131 and the third electrode layer 133. In this case, the first electrode layer 131 and the third electrode layer 133 can be considered as one electrode layer, and this electrode layer and the fourth electrode layer 134 are used together to receive one excitation electrical signal. This excitation electrical signal can be used to simultaneously control the refractive indices of the first grating region 1101 and the third grating region 1103.

[0069] It should also be noted that in the embodiment of the present application, the shape of the first groove 1141 and the second groove 1142 can be rectangular, square, etc. The present application does not impose any specific restrictions on the shape of the first groove 1141 and the second groove 1142, as long as it can achieve the electrical isolation function.

[0070] In the above implementation, the second electrode layer 132 and the fourth electrode layer 134 serve as the phase control component 13, thereby controlling the refractive index of the second grating region 1102 through electrical injection. Grooves are also designed between the electrode layers for electrical isolation. This implementation is simple and reliable, reducing the cost of the laser 100 while ensuring stable performance.

[0071] In an optional implementation, referring to FIG2 , the epitaxial structure 11 may further include a cap layer 115 and a first cladding layer 116. The cap layer 115 may also be referred to as an ohmic contact layer, and the first cladding layer 116 may also be referred to as an upper cladding layer of the epitaxial structure 11 in the epitaxial growth direction X.

[0072] Assuming that the depth of both the first groove 1141 and the second groove 1142 in the epitaxial growth direction X is d1, the depth d1 should be equal to or greater than the thickness of the cap layer 115 in the epitaxial growth direction X, and less than the sum of the thicknesses of the cap layer 115 and the first cladding layer 116 in the epitaxial growth direction X. Alternatively, from a fabrication process perspective, the first groove 1141 and the second groove 1142 are both etched, and both need to etch through the cap layer 115 and stop in the first cladding layer 116. Therefore, viewed from the direction opposite to the epitaxial growth direction X, the first groove 1141 and the second groove 1142 are etched starting from the cap layer 115 and reaching a certain position in the first cladding layer 116. Alternatively, the cap layer 115 can be understood as being divided into three separate sections by the first groove 1141 and the second groove 1142, with the first groove 1141 and the second groove 1142 passing through the cap layer 115, with portions of the grooves located in the first cladding layer 116.

[0073] In the above implementation, the first groove 1141 and the second groove 1142 are etched through the cover layer 115 to ensure that the first electrode layer 131, the second electrode layer 132 and the third electrode layer 133 are all insulated, thereby effectively ensuring that there will be no short circuit between the first electrode layer 131, the second electrode layer 132 and the third electrode layer 133.

[0074] In a feasible implementation, based on the structure shown in Figure 2, please refer to Figure 3, which is another structural schematic diagram of a laser provided by this application. Among them, (a) in Figure 3 is another side view of the laser 100, and (b) in Figure 3 is a top view of the laser 100. As shown in (a) in Figure 3 or (b) in Figure 3, the above-mentioned epitaxial structure 11 can also be designed with a ridge waveguide structure 117. The ridge waveguide structure 117 is located on the side of the epitaxial structure 11 facing away from the substrate layer 112. The ridge waveguide structure 117 includes a first ridge waveguide region 1171, a second ridge waveguide region 1172 and a third ridge waveguide region 1173, which are arranged in sequence in the cavity length direction Y and are obtained by dividing the first groove 1141 and the second groove 1142. In other words, a first groove 1141 is provided between the first ridge waveguide region 1171 and the second ridge waveguide region 1172, and a second groove 1142 is provided between the first ridge waveguide region 1171 and the third ridge waveguide region 1173. It can also be understood that the first groove 1141 and the second groove 1142 penetrate the ridge waveguide structure 117 in the epitaxial growth direction X to isolate the ridge waveguide structure 117 into the first ridge waveguide region 1171, the second ridge waveguide region 1172, and the third ridge waveguide region 1173.

[0075] The first surface 1131 mentioned above includes at least the surface of the first ridge waveguide region 1171 facing away from the grating layer 110, the surface of the second ridge waveguide region 1172 facing away from the grating layer 110, the surface of the third ridge waveguide region 1173 facing away from the grating layer 110, and the mesas on both sides of the ridge waveguide structure 117. It should be noted that the mesas on both sides of the ridge waveguide structure 117 may specifically include the mesas on both sides of the first ridge waveguide region 1171, the mesas on both sides of the second ridge waveguide region 1172, and the mesas on both sides of the third ridge waveguide region 1173.

[0076] In this case, the above-mentioned first electrode layer 131 is arranged on the surface of the first ridge waveguide region 1171 facing away from the grating layer 110, or the first part of the body of the first electrode layer 131 is arranged on the surface of the first ridge waveguide region 1171 facing away from the grating layer 110, and the second part of the body except the first part is arranged on the table on both sides of the first ridge waveguide region 1171.

[0077] The above-mentioned second electrode layer 132 is arranged on the surface of the second ridge waveguide region 1172 facing away from the grating layer 110, or the first part of the second electrode layer 132 is arranged on the surface of the second ridge waveguide region 1172 facing away from the grating layer 110, and the second part of the second electrode layer 132 except the first part is arranged on the table on both sides of the second ridge waveguide region 1172.

[0078] The above-mentioned third electrode layer 133 is arranged on the surface of the third ridge waveguide region 1173 facing away from the grating layer 110, or the first part of the body of the third electrode layer 133 is arranged on the surface of the third ridge waveguide region 1173 facing away from the grating layer 110, and the second part of the body except the first part is arranged on the table on both sides of the third ridge waveguide region 1173.

[0079] It should be noted that, in some feasible solutions, from the perspective of the manufacturing process, the ridge waveguide structure 117 can also be obtained by etching, and the etching is started from the original cover layer (i.e., the cover layer before etching) and stops at a certain position in the first cladding layer 116. Therefore, in this case, as shown in Figure 3 (a), the ridge waveguide structure 117 may include the cover layer 115 and part of the first cladding layer 116.

[0080] Furthermore, in this case, the first groove 1141 and the second groove 1142 pass through the cover layer 115, and a portion of the groove body is located in the first cladding layer 116. It should be understood that in this case, the depth d1 of the first groove 1141 and the second groove 1142 can be the same as or different from the height of the ridge waveguide structure 117. Generally, the depth d1 of the first groove 1141 and the second groove 1142 should be less than or equal to the height of the ridge waveguide structure 117. In addition, in this case, the mesas on both sides of the ridge waveguide structure 117 are part of the surface of the first cladding layer 116.

[0081] In other feasible solutions, when the epitaxial structure 11 also includes an etch stop layer, the ridge waveguide structure 117 can be etched starting from the original cover layer, passing through the first cladding layer 116, and stopping at a certain position in the etch stop layer. Therefore, in this case, the ridge waveguide structure 117 can include the cover layer 115, the first cladding layer 116, and a portion of the etch stop layer. Furthermore, in this case, the first groove 1141 and the second groove 1142 will only pass through the cover layer 115, and part of the groove body will be located in the first cladding layer 116. That is, in this case, the depth d1 of the first groove 1141 and the second groove 1142 will be less than the height of the ridge waveguide structure 117. In addition, in this case, the mesas on both sides of the ridge waveguide structure 117 are part of the surface of the etch stop layer.

[0082] In some feasible implementations, please refer to Figure 4, which is another structural schematic diagram of a laser provided by the present application. As shown in Figure 4, the phase control component 13 may include a heating component 135. The heating component 135 may be arranged on the first surface 1131 of the epitaxial structure 11, and the heating component 135 is close to the second grating region 1102. It can also be understood that the heating component 135 coincides with the projection of the second grating region 1102 in the opposite direction of the epitaxial growth direction X. The first surface 1131 is located on the side of the grating layer 110 facing away from the substrate layer 112 in the epitaxial structure. It can also be understood that the first surface 1131 is arranged opposite to the second surface 1132 of the epitaxial structure, and the second surface 1132 is the surface of the epitaxial structure 11 on the side of the substrate layer 112 facing away from the grating layer 110.

[0083] In actual operation, the heating component 135 is used to heat the second grating region 1102 under the action of the applied excitation electrical signal to change the refractive index of the second grating region 1102. Specifically, the laser 100 can control the heating temperature of the heating component 135 by controlling the circuit amplitude and the second amplitude of the excitation electrical signal applied to the heating component 135. When the heating temperature of the heating component 135 changes, the refractive index of the second grating region 1102 will also change accordingly due to the thermal effect.

[0084] In the above implementation, the heating component 135 is used as the phase control component 13, thereby electrically heating the refractive index of the second grating region 1102. This implementation is simple and reliable, and can reduce the cost of the laser 100.

[0085] In an optional implementation, the length of the heating component 135 in the cavity length direction Y can be less than or equal to the first length (here, assumed to be L) of the second grating region 1102 in the cavity length direction Y. Here, designing the length of the heating component 135 in the cavity length direction Y to be less than the first length of the second grating region 1102 in the cavity length direction Y can reduce thermal crosstalk with other regions of the laser 100 and reduce power fluctuations caused by heating.

[0086] In another optional structure based on the structure shown in Figure 4, please refer to Figure 5, which is another structural schematic diagram of a laser provided by this application. As shown in Figure 5, the above-mentioned epitaxial structure 11 is also provided with a third groove 1351 and a fourth groove 1352. Among them, the third groove 1351, the heating component 135 and the fourth groove 1352 are arranged in sequence in the cavity length direction Y. In other words, the third groove 1351 and the fourth groove 1352 are located at the first surface 1131 of the epitaxial structure 11 and are provided at the two sides of the heating component 135 in the cavity length direction Y.

[0087] In actual operation, the third groove 1351 is used to prevent heat from the heating element 135 from being transferred to the first grating region 1101. In other words, the third groove 1351 is used to achieve thermal isolation between the heating element 135 and the first grating region 1101. The fourth groove 1352 is used to prevent heat from the heating element 135 from being transferred to the third grating region 1103. In other words, the fourth groove 1352 is used to achieve thermal isolation between the heating element 135 and the third grating region 1103.

[0088] It should also be noted that in the embodiment of the present application, the shape of the third groove 1351 and the fourth groove 1352 can be rectangular, square, etc. The present application does not impose any specific restrictions on the shape of the third groove 1351 and the fourth groove 1352, as long as it can achieve the thermal isolation function.

[0089] In the above implementation, a third groove 1351 and a fourth groove 1352 are provided on both sides of the heating component 135 to achieve thermal isolation of the first grating region 1101 and the third grating region 1103. This not only improves the heating efficiency of the heating component 135 on the second grating region 1102, but also reduces thermal crosstalk in other areas of the laser 100 and reduces power fluctuations caused by heating.

[0090] Furthermore, based on the structures shown in Figures 4 and 5, please refer to Figure 6, which is another structural schematic diagram of a laser provided by the present application. Among them, Figure 6 (a) is another side view of the laser 100, Figure 6 (b) is another front view of the laser 100, and Figure 6 (c) is another side view of the laser 100. As shown in Figure 6, the epitaxial structure 11 can also be designed with a ridge waveguide structure 117. The ridge waveguide structure 117 is located on the side of the epitaxial structure 11 facing away from the substrate layer 112. The first surface 1131 mentioned above includes at least a third surface 1175 of the ridge waveguide structure 117 facing away from the grating layer 110 and the mesas on both sides of the ridge waveguide structure 117.

[0091] The heating element 135 is disposed on a mesa on either side of the ridge waveguide structure 117, such as the target mesa 1174 shown in FIG6 . Similarly, the third groove 1351 and the fourth groove 1352 are located in the region where the target mesa 1174 is located. In other words, the third groove 1351 and the fourth groove 1352 pass through the target mesa 1174 in a direction opposite to the epitaxial growth direction X, and one side opening of the third groove 1351 and the fourth groove 1352 is coplanar with the target mesa 1174.

[0092] Furthermore, based on the structure shown in FIG6 , the depths of the third groove 1351 and the fourth groove 1352 in the epitaxial growth direction X are both less than the thickness of the first cladding layer 116. Alternatively, from a manufacturing process perspective, the third groove 1351 and the fourth groove 1352 are both etched. Therefore, viewed from the direction opposite to the epitaxial growth direction X, the third groove 1351 and the fourth groove 1352 are etched starting from the target mesa 1174 and continuing to a certain position in the first cladding layer 116. This can also be understood as the groove bodies of the third groove 1351 and the fourth groove 1352 are both located in the first cladding layer 116.

[0093] It should be noted that, in some feasible solutions, from a manufacturing process perspective, the ridge waveguide structure 117 can also be obtained by etching, and the etching is started from the original cover layer (i.e., the cover layer before etching) and stops at a certain position in the first cladding layer 116. Therefore, as shown in Figure 6, the ridge waveguide structure 117 may include the cover layer 115 and a portion of the first cladding layer 116. In this case, the depth of the third groove 1351 and the fourth groove 1352 should be less than the height of the unetched portion of the first cladding layer 116.

[0094] In addition, as shown in FIG6( a ), the laser 100 may further include a fifth electrode layer 118 and a fourth electrode layer 134. The fifth electrode layer 118 is disposed on the third surface 1175 of the ridge waveguide structure 117, and the fourth electrode layer 134 is disposed on the second surface 1132 of the epitaxial structure 11. The fourth electrode layer 134 and the fifth electrode layer 118 may be used to receive an excitation electrical signal, which is used for the normal operation of the laser 100.

[0095] In an optional implementation, based on the structures shown in Figures 4-6, please refer to Figure 7, which is another schematic diagram of the structure of a laser provided by this application. As shown in Figure 7, the heating component 135 may include a thin film metal resistor 1353 and a first electrode 1354 and a second electrode 1355 connected to the ends of the thin film metal resistor 1353. The long axis direction of the thin film metal resistor 1353 is parallel to the cavity length direction Y of the laser 100.

[0096] In actual operation, the first electrode 1354 and the second electrode 1355 can be connected to an excitation electrical signal. The thin film metal resistor 1353 generates heat under the action of the excitation electrical signal, thereby heating the second grating region 1102 to change the refractive index of the second grating region 1102.

[0097] In the above implementation, the thin film metal resistor 1353 is used as the heating component 135 . The solution is simple and easy to implement, which can reduce the cost of the laser 100 .

[0098] It should be noted here that, in actual implementation, the heating component 135 may also be implemented in other possible ways, as long as it is applicable to the structure and design requirements of the laser 100 provided in this application. This application does not limit the specific implementation form of the heating component 135.

[0099] In some feasible implementations, the initial phase of the laser 100 provided in the present application can be determined by the first grating period S1, the second grating period S2, and the first length of the second grating region 1102 in the cavity length direction Y described above.

[0100] Optionally, the initial phase, the first grating period S1, the second grating period S2, and the first length satisfy the following formula (1):

[0101] Wherein, P is the initial phase and L is the first length.

[0102] Furthermore, when the initial phase and the first grating period S1, the second grating period S2, and the first length satisfy the aforementioned formula (1), for the laser 100 provided in the present application, during its design process, the values ​​of the first grating period S1, the second grating period S2, and the first length L can be adaptively designed so that the initial phase P of the laser 100 is a preset target phase. When the initial phase P of the laser 100 is the preset target phase, the difference between the first phase value corresponding to the band gap of the grating structure in the epitaxial structure 11 and the second phase value corresponding to the transmission bandwidth of the grating structure will be less than or equal to the preset difference. Here, the preset difference should be less than or equal to 0.1π. The above-mentioned second phase value is the phase value corresponding to the upper limit or lower limit of the transmission bandwidth of the grating structure.

[0103] That is, for the laser 100 provided in the present application, the initial phase can be made to reach a preset target phase by designing the values ​​of the first grating period S1, the second grating period S2, and the first length L, so that the initial phase value corresponding to the band gap of the grating structure in the epitaxial structure 11 can be as close as possible to the phase value corresponding to the upper limit or lower limit of the transmission bandwidth of the grating structure. Combined with the previous explanation of the continuous frequency sweep function, it can be seen that the band gap of the grating structure will continuously move with a period of 2π within the transmission bandwidth of the grating structure. If the design makes the initial phase value corresponding to the band gap of the grating structure as close as possible to the phase value corresponding to the upper limit or lower limit of the transmission bandwidth of the grating structure, the movable range of the band gap of the grating structure can be made larger. In this way, when the laser 100 realizes the continuous frequency sweep function, its frequency sweep range will become larger, which can improve the frequency sweep bandwidth of the laser 100.

[0104] It should be noted that the target phase is an empirical value obtained through multiple experiments on the laser 100 provided in this application, which can make the band gap of the grating structure as close as possible to the upper limit or lower limit of the transmission bandwidth of the grating structure. Since the value of the target phase will also change with the change of the first length mentioned above, this application does not impose any specific restrictions on the value of the target phase. For example, the initial phase P is generally set to a position that ensures single-mode lasing of the laser 100, such as any position between 0.6π and 0.8π.

[0105] It should also be noted that, since the bandgap of the grating structure can move in two directions within the transmission bandwidth of the grating structure, for the laser provided in this application, the initial phase P is designed to make the bandgap of the grating structure close to the upper limit or lower limit of the transmission bandwidth opposite to its movement direction. In other words, when the bandgap of the grating structure moves from 0 to 2π, the bandgap of the grating structure should be designed to be close to the lower limit of the transmission bandwidth. When the bandgap of the grating structure moves from 2π to 0, the bandgap of the grating structure should be designed to be close to the upper limit of the transmission bandwidth.

[0106] In some feasible implementations, please refer to Figure 8, which is another structural schematic diagram of a laser provided in the present application. As shown in (a) in Figure 8, the cavity surfaces of the laser 100 in the cavity length direction Y are respectively coated with an anti-reflection (AR) film 1193 and a high-reflection (HR) film 1194. Specifically, as shown in Figure 8, the first cavity surface 1191 of the laser 100 in the cavity length direction Y is coated with an AR film 1193, and the second cavity surface 1192 of the laser 100 in the cavity length direction Y is respectively coated with an HR film 1194. It can also be understood that the laser 100 adopts an AR-HR film system. In this case, the light wave generated by the laser 100 will be emitted from the first cavity surface 1191. And in this case, the ratio of the first length L to the second length of the grating layer 110 in the cavity length direction Y should be greater than or equal to 0.3 and less than or equal to 0.4.

[0107] As shown in (b) of Figure 8 , the laser 100 is coated with an AR film 1193 and an AR film 1195 on the cavity surface in the cavity length direction Y. Specifically, as shown in Figure 8 , the laser 100 is coated with an AR film 1193 on the first cavity surface 1191 in the cavity length direction Y, and the laser 100 is coated with an AR film 1195 on the second cavity surface 1192 in the cavity length direction Y. It can also be understood that the laser 100 adopts an AR-AR film system. In this case, the light waves generated by the laser 100 will be emitted simultaneously from the first cavity surface 1191 and the second cavity surface 1192. And in this case, the ratio of the first length L to the second length of the grating layer 110 in the cavity length direction Y should be greater than 0 and less than 1.

[0108] In some feasible implementations, the grating layer 110 provided in the present application may adopt a complex-coupled grating. This is because the complex-coupled grating has a smaller linewidth broadening factor, which is conducive to achieving a narrower linewidth output and lower relative intensity noise of the laser 100. In actual implementation, the complex-coupled grating layer includes at least one layer of N-type doped grating layer with a high refractive index and carrier inversion and a high refractive index P-type doped grating layer. During actual operation, the grating layer located below will produce periodic refractive index modulation, while the doped inversion material layer above will produce a large carrier concentration difference in the inversion layer when current is injected, introducing light loss and thus forming gain coupling with the imaginary part of the refractive index modulation. Therefore, the complex-coupled grating structure can introduce a negative feedback effect, which can reduce the effective linewidth enhancement factor, thereby facilitating the achievement of a narrower linewidth output and lower relative intensity noise of the laser 100.

[0109] For example, see Figure 9, which is a schematic diagram of the structure of a grating layer provided in this application. As shown in Figure 9, the grating layer 110 may include a first sub-grating layer 1104 and a second sub-grating layer 1105 arranged in sequence along the epitaxial growth direction X, wherein the first sub-grating layer 1104 is doped with N-type, and the second sub-grating layer 1105 is doped with P-type.

[0110] In some feasible implementations, please refer to FIG10 , which is another structural schematic diagram of a laser provided in the present application. As shown in FIG10 , the epitaxial structure 11 may further include a spacer layer 120, a first barrier layer 121, a first separation confinement heterojunction (SCH) layer 122, an MQW layer 123, a second SCH layer 124, a second barrier layer 125, a buffer layer 126, and a second cladding layer 127. Optionally, an etch stop layer (not shown) may also be included, which is generally disposed between the first cladding layer 116 and the filling layer 111. The first barrier layer 121, the first SCH layer 122, the MQW layer 123, the second SCH layer 124, and the second barrier layer 125 may constitute the active layer 128 of the epitaxial structure 11. When the structure shown in FIG10 is adopted, the laser 100 may also be referred to as a sandwich-type MQW semiconductor laser.

[0111] It should be noted that the present application does not impose any restrictions on the specific materials of each layer structure included in the epitaxial structure 11, as long as it can achieve the functions of the epitaxial structure 11 provided by the present application.

[0112] Furthermore, it should be noted that, in the structure shown in FIG. 10 , the grating layer 110 is disposed on the side of the MQW layer 123 facing away from the substrate layer 112 , or in other words, the grating layer 110 is disposed above the first barrier layer 121 .

[0113] In practical applications, the grating layer 110 can also be disposed between the MQW layer 123 and the substrate layer. Specifically, it can be disposed below the second barrier layer 125. In other words, the grating layer 110 can be fabricated as a bottom grating, which can optimize the square distribution and thus reduce the internal loss of the laser 100.

[0114] In some feasible implementations, based on the structure shown in FIG. 10 , please refer to FIG. 11 , which is another schematic diagram of a laser structure provided in this application. As shown in FIG. 11 , a first cavity 1281 may be provided in the active layer 128. The first cavity 1281 extends through the active layer 128 in the epitaxial growth direction X. That is, one end face of the first cavity 1281 is located on the interface between the first barrier layer 121 and the spacer layer 120, and the other end face is located on the interface between the second barrier layer 125 and the buffer layer 126. Furthermore, the first cavity 1281 and the second grating region 1102 are disposed opposite each other in the epitaxial growth direction Y. Alternatively, in the direction opposite to the epitaxial growth direction Y, the projections of the first cavity 1281 and the second grating region 1102 on the substrate layer 112 partially or completely overlap. Furthermore, the first cavity 1281 is also filled with a bulk waveguide 1282. Here, the so-called bulk waveguide may also be referred to as a bulk passive waveguide (BPW).

[0115] It should be noted that the length of the first cavity 1281 in a direction perpendicular to the cavity length direction Y may be less than or equal to the width of the epitaxial structure 11. In other words, in actual implementation, portions of the active layer on both sides of the first cavity 1281 may be disconnected or connected, and this application does not impose any restrictions on this.

[0116] In the above implementation, a first cavity 1281 is provided in the active layer 128 and filled with a bulk material waveguide 1282 , so that the second grating region 1102 only plays the role of adjusting the refractive index in the cavity without generating gain, which is beneficial to the performance stability of the laser 100 .

[0117] Optionally, the first effective refractive index of the bulk waveguide 1282 matches the second effective refractive index of the portion of the active layer located on both sides of the first cavity 1281. Here, the portion of the active layer on both sides of the first cavity 1281 can be understood as the portion of the active layer 128 located around the first cavity 1281.

[0118] Furthermore, the first effective refractive index of the bulk waveguide 1282 matches the second effective refractive index of a portion of the active layer, which can be understood as the mode field spot areas calculated from the two effective refractive indices are equal.

[0119] In some feasible implementations, the laser 100 provided in this application may specifically be a DFB laser. It should be understood that the laser 100 may also be other types of lasers, and this application does not limit this.

[0120] It should also be noted that for the laser 100 provided in this application, the length of the second grating region 1102 should be designed to be as large as possible, because the larger the length of the second grating region 1102, the smaller the refractive index change required to control the laser 100, and the corresponding power consumption is also smaller.

[0121] The present application also provides a laser array. Referring to FIG12 , FIG12 is a schematic diagram of the structure of a laser array provided by the present application. As shown in FIG12 , the laser array 300 may include at least two lasers 100 provided by the present application.

[0122] In actual operation, the laser array 300 emits at least two light waves simultaneously through the two lasers 100 .

[0123] It should be understood that FIG12 is merely schematic. In actual implementation, the laser array 300 may further include other components, such as a power supply, a control circuit, etc., which will not be described in detail in this application.

[0124] The present application also provides an optical device. Referring to FIG13 , FIG13 is a schematic diagram of the structure of an optical device provided by the present application. As shown in FIG13 , the optical device 500 may include a laser 100 or the laser array 300 described above.

[0125] In actual operation, the laser 100 or the laser array 300 described above is used to provide the optical device 500 with the required light waves.

[0126] Optionally, the optical device 500 may specifically be an OLT or an ONU.

[0127] It should be understood that FIG13 is merely schematic. In actual implementation, the optical device 500 may also include other components, such as a power supply, a controller, an optical module, etc., which will not be described in detail in this application.

[0128] The terms "first," "second," "third," and "fourth," etc., in the specification and claims of this application and the accompanying drawings are used to distinguish between different objects, rather than to describe a specific order. In addition, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements, but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0129] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0130] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of this application. It should be understood that the above description is only the specific implementation methods of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent replacements, improvements, etc. made on the basis of the technical solutions of this application should be included in the scope of protection of this application.

Claims

1. A laser, characterized in that: The laser comprises an epitaxial structure and a phase control component, wherein the grating layer in the epitaxial structure comprises a first grating region, a second grating region, and a third grating region sequentially arranged in the cavity length direction of the laser, wherein a first grating period corresponding to the second grating region is greater than a second grating period corresponding to the first grating region and the third grating region; When the laser emits light waves, the phase control component is used to control the intra-cavity phase of the laser by changing the refractive index of the second grating region, thereby controlling the wavelength of the light waves.

2. The laser according to claim 1, characterized in that The laser comprises a first electrode layer, a second electrode layer, and a third electrode layer arranged on a first surface of the epitaxial structure, and a fourth electrode layer arranged on the second surface of the epitaxial structure, the first surface being located on a side of the grating layer facing away from a substrate layer in the epitaxial structure, the second surface being a surface of the substrate layer facing away from the grating layer, the first electrode layer and the first grating region being arranged opposite to each other in an epitaxial growth direction of the epitaxial structure, the second electrode layer and the second grating region being arranged opposite to each other in the epitaxial growth direction, the third electrode layer and the third grating region being arranged opposite to each other in the epitaxial growth direction, a first groove being arranged between the first electrode layer and the second electrode layer, and a second groove being arranged between the second electrode layer and the third electrode layer; The first groove is used to achieve electrical isolation between the first electrode layer and the second electrode layer, and the second groove is used to achieve electrical isolation between the second electrode layer and the third electrode layer; The phase control component includes the second electrode and the fourth electrode, and the refractive index of the second grating region is controlled by an excitation electrical signal input to the second electrode layer and the fourth electrode layer.

3. The laser according to claim 2, characterized in that The depths of the first groove and the second groove in the epitaxial growth direction are equal to or greater than the thickness of the cover layer, and less than the sum of the thicknesses of the cover layer and the first cladding layer in the epitaxial structure that contacts the cover side.

4. The laser according to claim 2 or 3, characterized in that The epitaxial structure further includes a ridge waveguide structure, the ridge waveguide structure including a first ridge waveguide region, a second ridge waveguide region, and a third ridge waveguide region, which are divided by a first groove and a second groove and arranged in sequence in the cavity length direction; the first surface at least includes surfaces of the first ridge waveguide region, the second ridge waveguide region, and the third ridge waveguide region facing away from the grating layer, and mesas on both sides of the ridge waveguide structure; The second electrode layer is arranged on the surface of the second ridge waveguide region facing away from the grating layer, or the first part of the second electrode layer is arranged on the surface of the second ridge waveguide region facing away from the grating layer, and the second part of the second electrode layer except the first part is arranged on the table on both sides of the second ridge waveguide region.

5. The laser according to claim 1, characterized in that The phase control component includes a heating component, the heating component is disposed on a first surface of the epitaxial structure, the heating component is close to the second grating region, and the first surface is located on a side of the grating layer facing away from the substrate layer in the epitaxial structure; The heating component is used to heat the second grating region under the action of the input excitation electrical signal to change the refractive index of the second grating region.

6. The laser according to claim 5, characterized in that The length of the heating component in the direction of the cavity length is less than or equal to the first length of the second grating region in the direction of the cavity length.

7. The laser according to claim 5 or 6, characterized in that The epitaxial structure is further provided with a third groove and a fourth groove, wherein the third groove, the heating component and the fourth groove are arranged in sequence in the length direction of the cavity; The third groove is used to block the heat of the heating component from being transmitted to the first grating region, and the fourth groove is used to block the heat of the heating component from being transmitted to the third grating region.

8. The laser according to any one of claims 5 to 7, characterized in that: The epitaxial structure also includes a ridge waveguide structure, the first surface includes a third surface of the ridge waveguide structure facing away from the grating layer and table surfaces on both sides of the ridge waveguide structure, the heating component is arranged on a target table surface on either side of the ridge waveguide structure, and the third groove and the fourth groove are located in the area where the target table surface is located.

9. The laser according to claim 8, characterized in that The depths of the third groove and the fourth groove in the epitaxial growth direction of the epitaxial structure are both smaller than the thickness of the first cladding layer in the epitaxial structure that is in contact with the cap layer.

10. The laser according to any one of claims 5 to 9, characterized in that: The heating component includes a thin film metal resistor and a first electrode and a second electrode respectively connected to the two ends of the thin film metal resistor. The long axis direction of the thin film metal resistor is parallel to the cavity length direction of the laser. The thin film metal resistor heats the second grating area under the action of the excitation electrical signal connected to the first electrode and the second electrode.

11. The laser according to any one of claims 1 to 10, characterized in that: The initial phase of the laser is determined by the first grating period, the second grating period, and a first length of the second grating region in the cavity length direction of the laser.

12. The laser according to claim 11, characterized in that The initial phase of the laser is a preset target phase, the difference between a first phase value corresponding to the band gap of the grating structure in the epitaxial structure and a second phase value corresponding to the transmission bandwidth of the grating structure is less than or equal to the preset difference, the second phase value is a phase value corresponding to the upper limit value or lower limit value of the transmission bandwidth of the grating structure, and the grating structure includes the grating layer and a filling layer in the epitaxial structure that is in contact with the grating layer.

13. The laser according to claim 11 or 12, characterized in that The initial phase of the laser, the first grating period, the second grating period, and the first length satisfy the following formula: Wherein, P is the initial phase, L is the first length, S1 is the first grating period, and S2 is the second grating period.

14. The laser according to any one of claims 11 to 13, characterized in that: The cavity surfaces of the laser in the cavity length direction are respectively coated with an anti-reflection film and a high-reflection film, and the ratio of the first length to the second length of the grating layer in the cavity length direction is greater than or equal to 0.3 and less than or equal to 0.

4.

15. The laser according to any one of claims 1 to 14, characterized in that: The grating layer includes a first sub-grating layer and a second sub-grating layer sequentially arranged in the epitaxial growth direction of the epitaxial structure. The first sub-grating layer adopts N-type doping, and the second sub-grating layer adopts P-type doping.

16. The laser according to any one of claims 1 to 15, characterized in that The active layer in the epitaxial structure is provided with a first cavity, which penetrates the active layer in the epitaxial growth direction of the epitaxial structure. The first cavity and the second grating region are arranged opposite to each other in the epitaxial growth direction, and the first cavity is filled with a bulk material waveguide.

17. The laser according to claim 16, characterized in that The first effective refractive index of the bulk waveguide matches the second effective refractive index of a portion of the active layer located on both sides of the first cavity.

18. The laser according to any one of claims 1 to 17, characterized in that The epitaxial structure further includes a multi-quantum well layer and a substrate layer. The grating layer is arranged on a side of the multi-quantum well layer facing away from the substrate layer, or the grating layer is arranged between the multi-quantum well layer and the substrate layer.

19. A laser array, characterized in that: The laser array comprises at least two lasers according to any one of claims 1-18.

20. An optical device, characterized in that: The optical device comprises the laser according to any one of claims 1 to 18, or comprises the laser array according to claim 19.

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