Laser, laser array and optical equipment

Abstract

The invention relates to the technical field of optics, in particular to a laser, a laser array and optical equipment. The laser includes 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 the cavity length direction of the laser. A first grating period corresponding to the second grating area is larger than a second grating period corresponding to the first grating area and the third grating area. In the process that the laser emits light waves, the phase control component is used for controlling the intra-cavity phase of the laser by changing the refractive index of the second grating area so as to control the wavelength of the light waves. The laser is high in frequency sweeping speed and high in applicability and practicability.

Description

Technical Field

[0001] The present application relates to the field of optical technologies, and particularly to a laser, a laser array, and an optical device. Background Art

[0002] With the continuous development of optical technologies, the application scenarios of lasers with continuously tunable wavelengths have been continuously broadened. For example, they can be applied to coherent optical communication systems, frequency modulated continuous wave (FMCW) radars, wavelength division multiplexer (WDM) systems, etc. As one of the core components, the operating state of a laser with a continuously tunable wavelength will directly affect the overall performance of the device or system in which it is located. Therefore, the performance of lasers with continuously tunable wavelengths has become one of the key concerns of people.

[0003] Benefiting from advantages such as low cost, simple structure, and low process difficulty, distributed feedback (DFB) lasers capable of achieving continuous wavelength tuning are widely used. Existing DFB lasers usually achieve continuous frequency sweeping by adjusting the internal thermo electric cooler (TEC) and current. However, the response time of the TEC is relatively long, which results in a large limitation on the frequency sweeping speed of existing DFB lasers, seriously affecting the applicability and practicality of DFB lasers. Summary of the Invention

[0004] To solve the above problems, the present application provides a laser, a laser array, and an optical device. The laser has a fast frequency sweeping speed, strong applicability and practicality. By using this laser, the problem of large limitations on the frequency sweeping speed of existing DFB lasers can be solved.

[0005] The following introduces the present application from multiple aspects. It is easy to understand that the implementation methods of the following multiple aspects can refer to each other.

[0006] In a first aspect, the present application provides a laser. The laser includes an epitaxial structure and a phase control component. The grating layer in the epitaxial structure includes a first grating region, a second grating region, and a third grating region arranged in sequence in the cavity length direction of the laser. The first grating period corresponding to the second grating region is greater than the second grating periods corresponding to the first grating region and the third grating region. During the process of the laser emitting light waves, the phase control component is used to control the in-cavity phase of the laser by changing the refractive index of the second grating region, thereby controlling the wavelength of the light waves.

[0007] In the above implementation, the phase control component in the laser can be used to control the in-cavity 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 method of controlling the in-cavity phase of the laser by controlling the refractive index of the grating region to change the lasing wavelength has a very short response time and can achieve continuous control of the lasing wavelength, the laser provided in this application can achieve fast and continuous control of the lasing wavelength through the phase control component. Therefore, its sweeping speed is very fast when realizing the frequency-sweeping function. Therefore, by adopting the solution provided in this application, the problem of slow frequency-sweeping speed of the existing DFB laser can be solved, and the applicability and practicability of the DFB laser can be improved.

[0008] In combination with the first aspect, in some possible implementation manners, the laser includes a first electrode layer, a second electrode layer, and a third electrode layer disposed on the first surface of the epitaxial structure, and a fourth electrode layer disposed on the second surface of the epitaxial structure. The first surface is 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 is disposed opposite to the first grating region in the epitaxial growth direction of the epitaxial structure. The second electrode layer is disposed opposite to the second grating region in the epitaxial growth direction, and the third electrode layer is disposed opposite to the third grating region in the epitaxial growth direction. A first groove is provided between the first electrode layer and the second electrode layer, and a second groove is provided between the second electrode layer and the third electrode layer. The first groove is used to electrically isolate the first electrode layer and the second electrode layer, and the second groove is used to electrically isolate 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 the excitation electrical signals applied to the second electrode layer and the fourth electrode layer.

[0009] In the above implementation, the second electrode layer and the fourth electrode layer are used as the phase control component, so as to realize the control of the refractive index of the second grating region by means of electrical injection. Grooves for electrical isolation are also designed between the electrode layers. This implementation method is simple and reliable, and can ensure the stable performance of the laser while reducing the cost of the laser.

[0010] In combination with the first aspect, in some possible implementation manners, the depths of the first groove and the second groove in the epitaxial growth direction are both equal to or greater than the thickness of the cover layer, and less than the sum of the thickness of the cover layer and the thickness of the first cladding layer in the epitaxial structure that is in contact with the cover layer side.

[0011] 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 from each other, thereby effectively ensuring that there is no short-circuit situation between the first electrode layer, the second electrode layer, and the third electrode layer.

[0012] In combination with the first aspect, in some possible implementation manners, 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 that are sequentially arranged in the cavity length direction and are divided by a first groove and a second groove. The first surface at least includes 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 and the mesa surfaces 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 a first part of the body of the second electrode layer is disposed on the surface of the second ridge waveguide region facing away from the grating layer, and a second part of the body of the second electrode layer other than the first part is disposed on the mesa surfaces on both sides of the second ridge waveguide region.

[0013] In combination with the first aspect, in some possible implementation manners, the phase control component includes a heating component. The heating component is disposed on the first surface of the epitaxial structure. The heating component is close to the second grating region. The first surface is located on the side of the grating layer facing away from the substrate layer in the epitaxial structure. The heating component is configured to heat the second grating region under the action of an applied excitation electrical signal to change the refractive index of the second grating region.

[0014] In the above implementation, the heating component is used as the phase control component, so as to realize the control of the refractive index of the second grating region by means of electric heating. This implementation manner is simple and reliable, and can reduce the cost of the laser.

[0015] In combination with the first aspect, in some possible implementation manners, 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 the thermal crosstalk in other regions of the laser and reduce the power fluctuation caused by heating.

[0016] In combination with the first aspect, in some possible implementation manners, the epitaxial structure is further provided with a third groove and a fourth groove. The third groove, the heating component, and the fourth groove are sequentially arranged in the cavity length direction. The third groove is configured to block the heat of the heating component from propagating to the first grating region, and the fourth groove is configured to block the heat of the heating component from propagating to the third grating region.

[0017] In the above implementation, the third groove and the fourth groove are arranged on both sides of the heating component to achieve thermal isolation of the first grating region and the third grating region. In this way, not only can the heating efficiency of the heating component for the second grating region be improved, but also the thermal crosstalk in other regions of the laser can be reduced and the power fluctuation caused by heating can be reduced.

[0018] In combination with the first aspect, in some possible implementation manners, the epitaxial structure further includes a ridge waveguide structure. The first surface includes a third surface of the ridge waveguide structure facing away from the grating layer and mesa surfaces on both sides of the ridge waveguide. The heating component is disposed on a target mesa surface on any one side of the ridge waveguide structure, and the third groove and the fourth groove, and the second groove are located in the region where the target mesa surface is located.

[0019] In combination with the first aspect, in some possible implementation manners, 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 contacts the cover layer.

[0020] In combination with the first aspect, in some possible implementation manners, the heating component includes a thin-film metal resistor and a first electrode and a second electrode respectively connected to 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 region under the action of an excitation electrical signal accessed by the first electrode and the second electrode.

[0021] In the above implementation, using the thin-film metal resistor as the heating component, the solution is simple and easy to implement, and the cost of the laser can be reduced.

[0022] In combination with the first aspect, in some possible implementation manners, 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.

[0023] In combination with the first aspect, in some possible implementation manners, the initial phase of the laser is a preset target phase. The difference between a first phase value corresponding to the bandgap 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 a preset difference value. The second phase value is the phase value corresponding to the upper limit value or the lower limit value of the transmission bandwidth of the grating structure.

[0024] For the laser provided in this application, the initial phase can be made to reach the 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 bandgap of the grating structure in the epitaxial structure can be as close as possible to the phase value corresponding to the upper limit value or the lower limit value of the transmission bandwidth of the grating structure. Since the bandgap of the grating structure moves continuously within the transmission bandwidth of the grating structure with a period of 2π, if the design makes the initial phase value corresponding to the bandgap of the grating structure as close as possible to the phase value corresponding to the upper limit value or the lower limit value of the transmission bandwidth of the grating structure, the movable range of the bandgap of the grating structure can be made larger. In this way, when the laser realizes the continuous frequency-sweeping function, its frequency-sweeping range will become larger, and the frequency-sweeping bandwidth of the laser can be improved.

[0025] In combination with the first aspect, in some possible implementation manners, the initial phase of the laser, the first grating period, the second grating period, and the first length satisfy the following formula:

[0026]

[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 implementation manners, anti-reflection films and high-reflection films are respectively coated on the cavity surfaces of the laser in the cavity length direction, 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 implementation manners, 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 is doped with N-type, and the second sub-grating layer is doped with P-type.

[0030] In the above implementation, the grating layer adopts a complex-coupling grating structure, which can introduce a negative feedback effect, reduce the effective linewidth enhancement factor, and thus is beneficial to realizing a narrower linewidth output and lower relative intensity noise of the laser.

[0031] In combination with the first aspect, in some possible implementation manners, a first cavity is arranged in the active layer of the epitaxial structure, 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 oppositely arranged 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 implementation manners, the first effective refractive index of the bulk material waveguide matches the second effective refractive index of the partial active layer on both sides of the first cavity.

[0033] In combination with the first aspect, in some possible implementation manners, the epitaxial structure further includes a multi-quantum well layer and a substrate layer, the grating layer is arranged on the 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. In the above implementation, arranging the grating layer between the multi-quantum well (MQW) layer and the substrate layer, that is, preparing the grating layer as a bottom grating, can optimize the square distribution and thus reduce the internal loss of the laser.

[0034] In combination with the first aspect, in some possible implementation manners, 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 emits at least two light waves simultaneously through these two lasers.

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

[0037] Combined with 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 by the present application has a fast sweep speed and strong applicability and practicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a schematic structural diagram of a laser provided by the present application;

[0040] Figure 2 is another schematic structural diagram of a laser provided by the present application;

[0041] Figure 3 is another schematic structural diagram of a laser provided by the present application;

[0042] Figure 4 is another schematic structural diagram of a laser provided by the present application;

[0043] Figure 5 is another schematic structural diagram of a laser provided by the present application;

[0044] Figure 6 is another schematic structural diagram of a laser provided by the present application;

[0045] Figure 7 is another schematic structural diagram of a laser provided by the present application;

[0046] Figure 8 is another schematic structural diagram of a laser provided by the present application;

[0047] Figure 9 is a schematic structural diagram of a grating layer provided by the present application;

[0048] Figure 10 is another schematic structural diagram of a laser provided by the present application;

[0049] Figure 11 is another structural schematic diagram of a laser provided by this application;

[0050] Figure 12 is a structural schematic diagram of a laser array provided by this application;

[0051] Figure 13 is a structural schematic diagram of an optical device provided by this application. Detailed implementation manners

[0052] Next, the technical solutions in the embodiments of this application will be clearly and completely described in conjunction with the accompanying drawings provided in the embodiments of this application.

[0053] In this application, "at least one" means one or more, and "a plurality" 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 may represent: A exists alone, A and B exist simultaneously, and B exists alone, where A and B may be singular or plural. In the text description of this application, the character " / " generally represents an "or" relationship between the associated objects before and after; in the formulas of this application, the character " / " represents a "division" relationship between the associated objects before and after. "Including at least one of A, B, and C" may represent: 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 usually achieve continuous frequency sweeping by adjusting the internal TEC and current. However, the response time of the TEC is relatively long, which results in a large limitation on the frequency sweeping speed of existing DFB lasers, seriously affecting the applicability and practicality of DFB lasers.

[0055] Therefore, the technical problem to be solved by this application is: how to improve the frequency sweeping speed of DFB lasers, thereby enhancing the applicability and practicality of DFB lasers.

[0056] Please refer to Figure 1 , Figure 1 is a structural schematic diagram of a laser provided by this application. It should be understood that Figure 1 is a front view of the laser 100. As Figure 1 shown, 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 in the cavity length direction (here assumed to be the Y direction) of the laser 100. The first grating period corresponding to the second grating region 1102 (i.e., Figure 1The grating period S1 shown in [reference] is greater than the second grating period corresponding to the first grating region 1101 and the third grating region 1103 (i.e., Figure 1 the grating period S2 shown in [reference]). That is to say, the grating layer 110 can be composed of three uniform gratings arranged in sequence in 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 of the epitaxial structure 11 (here assumed to be the direction X). The above-mentioned phase control component 13 is arranged close to the second grating region 1102.

[0057] In actual operation, when the laser 100 emits light waves, the above-mentioned phase control component 13 is used to control the in-cavity phase of the laser 100 by changing the refractive index of the second grating region 1102, so as to control the wavelength of the light waves 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 in-cavity phase of the laser 100 by changing the refractive index of the second grating region 1102, so that the wavelength of the light waves emitted by the laser 100 changes continuously, enabling the laser 100 to achieve the continuous frequency sweeping function.

[0058] It should be explained that the laser 100 may further 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 (this grating structure can also be understood as the Bragg grating in the epitaxial structure 11). The structural design of the grating layer 110 introduces a bandgap in the transmission bandwidth of the grating structure. Generally, this bandgap 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 breaks the degeneracy of its modes, so that the lasing wavelength of the laser 100 (i.e., the wavelength of the light waves it emits) is located at the position of the above-mentioned bandgap. 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 (and the in-cavity phase of the laser 100 will also change), so that the lasing wavelength of the laser 100 changes accordingly. It should be noted that the bandgap moves continuously within the transmission bandwidth of the grating structure with a period of 2π. Therefore, continuously controlling the refractive index of the second grating region 1102 of the laser 100 can make the lasing wavelength of the laser 100 change continuously, so that the laser 100 realizes the continuous frequency sweeping function. And because the bandgap moves within the transmission bandwidth of the grating structure with a period of 2π, the maximum range that the continuous frequency sweeping trajectory of the laser 100 can reach does not exceed the transmission bandwidth of the grating structure.

[0059] It should also be noted that the epitaxial structure 11 provided in this application can be understood as the laser body of the laser 100 or 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 method of controlling the intracavity phase of the laser by controlling the refractive index of the grating region to change the lasing wavelength has a very short response time and can achieve continuous control of the lasing wavelength, the laser 100 provided in this application can achieve fast and continuous control of the lasing wavelength through the phase control component 13. Therefore, its sweep speed is very fast when implementing the frequency-sweeping function. Therefore, by adopting the solution provided in this application, the problem of slow sweep speed of the existing DFB laser can be solved, and the applicability and practicality of the DFB laser can be improved.

[0061] [[ID=#7]]In some alternative implementation manners, please refer to Figure 2 , Figure 2 which is another schematic structural diagram of a laser provided in this application. As Figure 2 shown, the above-mentioned laser 100 may include a first electrode layer 131, a second electrode layer 132, and a third electrode layer 133 disposed on the first surface 1131 of the epitaxial structure 11. Here, for the convenience of understanding, Figure 2 it is shown in the form that the first electrode layer 131, the second electrode layer 132, and the third electrode layer 133 are 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 further include a fourth electrode layer 134 disposed on the second surface 1132 of the epitaxial structure 11. Similarly, for the convenience of understanding, Figure 2 it is shown in the form that the fourth electrode layer 134 is separated from the second surface 1132. In actual implementation, the fourth electrode layer 134 is in contact with the second surface 1132. As Figure 2 shown, 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. Or rather, 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. Or rather, 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 oppositely arranged in the epitaxial growth direction X. Or rather, in the direction opposite to the epitaxial growth direction X, the projection of the first electrode layer 131 and the first grating region 1101 on the substrate layer 112 partially or completely overlaps. The second electrode layer 132 and the second grating region 1102 are oppositely arranged in the epitaxial growth direction X. Or rather, in the direction opposite to the epitaxial growth direction X, the projection of the second electrode layer 132 and the second grating region 1102 on the substrate layer 112 partially or completely overlaps. The third electrode layer 133 and the third grating region 1103 are oppositely arranged in the epitaxial growth direction X. Or rather, in the direction opposite to the epitaxial growth direction X, the projection of the third electrode layer 133 and the third grating region 1103 on the substrate layer 112 partially or completely overlaps.

[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 non-electrically connected regions formed after etching the first groove 1141 and the second groove 1142 in the same electrode layer.

[0064] It should be added that in the case of having the first groove 1141 and the second groove 1142, the above-mentioned cover layer 115 is also divided into three different regions arranged in sequence in the cavity length direction Y, which are respectively named the first cover region, the second cover region, and the third cover region here. The aforementioned first surface 1131 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 above-mentioned first electrode layer 131 can be disposed on the surface of the first cover region facing away from the grating layer 110, the above-mentioned second electrode layer 132 can be disposed on the surface of the second cover region facing away from the grating layer 110, and the above-mentioned 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. By adopting the design of the first groove 1141 and the second groove 1142, the situation of short circuit of the first electrode layer 131, the second electrode layer 132, and the third electrode layer 133 can be avoided, and the working stability of the laser 100 can be ensured.

[0066] In addition, the aforementioned phase control component 13 may include the second electrode layer 132 and the fourth electrode layer 134. During actual operation, the second electrode layer 132 and the fourth electrode layer 134 are electrically connected and can be used to access an excitation electrical signal (for convenience of distinction, the first excitation electrical signal will be used hereinafter for representation). The refractive index of the aforementioned 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. That is to say, 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, so as to achieve 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 supplemented here that during actual implementation, the first electrode layer 131 and the fourth electrode layer 134 are also electrically connected and can be used to access another excitation electrical signal (for convenience of distinction, the second excitation electrical signal will be used hereinafter for representation). 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 access yet another excitation electrical signal (for convenience of distinction, the third excitation electrical signal will be used hereinafter for representation). The third excitation electrical signal can be used to control the refractive index of the third grating region 1103. Optionally, there may also 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 regarded as one electrode layer, and this electrode layer and the fourth electrode layer 134 are jointly used to access an excitation electrical signal, and the 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 embodiments of the present application, the groove shapes of the first groove 1141 and the second groove 1142 can be rectangular, square, etc. The present application does not make specific limitations on the groove shapes 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 are used as the phase control component 13, so as to control the refractive index of the second grating region 1102 by means of electrical injection. Grooves for electrical isolation are also designed between the electrode layers. This implementation is simple and reliable, and can ensure the stable performance of the laser 100 while reducing the cost of the laser 100.

[0071] In an alternative implementation, please continue to refer to Figure 2 , the epitaxial structure 11 may further include a cover layer 115 and a first cladding layer 116. Among them, the cover layer 115 can also be called an ohmic contact layer, and the first cladding layer 116 can also be called the upper cladding layer of the epitaxial structure 11 in the epitaxial growth direction X.

[0072] Assume that the depths of the first groove 1141 and the second groove 1142 in the epitaxial growth direction X are both d1. Then the depth d1 should be equal to or greater than the thickness of the cover layer 115 in the epitaxial growth direction X, and less than the sum of the thicknesses of the cover layer 115 and the first cladding layer 116 in the epitaxial growth direction X. Or, in terms of the manufacturing process, the first groove 1141 and the second groove 1142 are both etched, and both need to etch through the cover layer 115 and stop in the first cladding layer 116. Therefore, from the opposite direction of the epitaxial growth direction X, the first groove 1141 and the second groove 1142 start etching from the cover layer 115 and etch to a certain position in the first cladding layer 116. It can also be understood that the cover layer 115 is divided into three independent parts by the first groove 1141 and the second groove 1142, and the first groove 1141 and the second groove 1142 pass through the cover layer 115, and part of the groove body is located in the first cladding layer 116.

[0073] In the above implementation, etching the first groove 1141 and the second groove 1142 through the cover layer 115 can ensure that the first electrode layer 131, the second electrode layer 132 and the third electrode layer 133 are all insulated from each other, thus effectively ensuring that there is no short - circuit situation between the first electrode layer 131, the second electrode layer 132 and the third electrode layer 133.

[0074] In a feasible implementation, on the basis of the structure shown in Figure 2 , please refer to Figure 3 , Figure 3 is another schematic structural diagram of a laser provided by the present application. Among them, Figure 3 (a) in is another side view of the laser 100, Figure 3 (b) in is a top view of the laser 100. As shown in Figure 3 (a) in or Figure 3As shown in (b) of , 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 that are arranged in sequence in the cavity length direction Y and are divided by a first groove 1141 and a second groove 1142. Or, 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 it into a first ridge waveguide region 1171, a second ridge waveguide region 1172, and a third ridge waveguide region 1173.

[0075] The first surface 1131 described above at least includes 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 mesa surfaces on both sides of the ridge waveguide structure 117. It should be noted here that the mesa surfaces on both sides of the ridge waveguide structure 117 specifically may include the mesa surfaces on both sides of the first ridge waveguide region 1171, the mesa surfaces on both sides of the second ridge waveguide region 1172, and the mesa surfaces on both sides of the third ridge waveguide region 1173.

[0076] In this case, the above-mentioned first electrode layer 131 is disposed 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 disposed on the surface of the first ridge waveguide region 1171 facing away from the grating layer 110, and the second part of the body other than the first part of the body is disposed on the mesa surfaces on both sides of the first ridge waveguide region 1171.

[0077] The above-mentioned second electrode layer 132 is disposed on the surface of the second ridge waveguide region 1172 facing away from the grating layer 110, or, the first part of the body of the second electrode layer 132 is disposed on the surface of the second ridge waveguide region 1172 facing away from the grating layer 110, and the second part of the body other than the first part of the body is disposed on the mesa surfaces on both sides of the second ridge waveguide region 1172.

[0078] The above-mentioned third electrode layer 133 is disposed 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 disposed on the surface of the third ridge waveguide region 1173 facing away from the grating layer 110, and the second part of the body other than the first part of the body is disposed on the mesa surfaces on both sides of the third ridge waveguide region 1173.

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

[0080] Furthermore, in this case, the first groove 1141 and the second groove 1142 penetrate the cover layer 115, and part 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 may be the same 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 mesa on both sides of the ridge waveguide structure 117 is a partial surface of the first cladding layer 116.

[0081] In some other feasible solutions, when the epitaxial structure 11 further 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 may include the cover layer 115, the first cladding layer 116, and a partial body of the etch stop layer. Furthermore, in this case, the first groove 1141 and the second groove 1142 only penetrate the cover layer 115, and part of the groove body is located in the first cladding layer 116. That is to say, in this case, the depth d1 of the first groove 1141 and the second groove 1142 is less than the height of the ridge waveguide structure 117. In addition, in this case, the mesa on both sides of the ridge waveguide structure 117 is a partial surface of the etch stop layer.

[0082] In some feasible implementation manners, please refer to Figure 4 , Figure 4 which is another schematic structural diagram of a laser provided by this application. As shown in Figure 4As shown, the phase control component 13 may include a heating component 135. The heating component 135 may be disposed 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 a projection part of the heating component 135 coincides with 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 disposed 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, due to the thermal effect, the refractive index of the second grating region 1102 will also change accordingly.

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

[0085] In an alternative implementation, the length of the heating component 135 in the cavity length direction Y may be less than or equal to the first length (assumed to be L here) 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 the thermal crosstalk in other regions of the laser 100 and reduce the power fluctuation caused by heating.

[0086] In another alternative Figure 4 Based on the structure shown, please refer to Figure 5 , Figure 5 is another schematic structural diagram of a laser provided by the present application. As Figure 5 shown, the above-mentioned epitaxial structure 11 is further 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. Or rather, the third groove 1351 and the fourth groove 1352 are located at the first surface 1131 of the epitaxial structure 11 and are disposed on two side surfaces of the heating component 135 in the cavity length direction Y.

[0087] In actual work, the third groove 1351 is used to block the heat of the heating component 135 from propagating to the first grating region 1101. Or rather, the third groove 1351 is used to achieve thermal isolation between the heating component 135 and the first grating region 1101. The fourth groove 1352 is used to block the heat of the heating component 135 from propagating to the third grating region 1103. Or rather, the fourth groove 1352 is used to achieve thermal isolation between the heating component 135 and the third grating region 1103.

[0088] It should also be noted that in the embodiments of the present application, the groove shapes of the third groove 1351 and the fourth groove 1352 can be rectangular, square, etc. The present application does not specifically limit the groove shapes of the third groove 1351 and the fourth groove 1352, as long as they can achieve the thermal isolation function.

[0089] In the above implementation, the third groove 1351 and the fourth groove 1352 are arranged 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 can not only improve the heating efficiency of the heating component 135 for the second grating region 1102, but also reduce the thermal crosstalk in other regions of the laser 100 and reduce the power fluctuation caused by heating.

[0090] Furthermore, on the basis of Figure 4 and Figure 5 the structure shown, please refer to Figure 6 , Figure 6 which is another schematic structural diagram of a laser provided by the present application. Among them, Figure 6 in (a) is another side view of the laser 100, Figure 6 in (b) is another front view of the laser 100, Figure 6 in (c) is another side view of the laser 100. As Figure 6 shown, 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 aforementioned first surface 1131 at least includes the third surface 1175 of the ridge waveguide structure 117 facing away from the grating layer 110 and the mesa surfaces on both sides of the ridge waveguide structure 117.

[0091] The aforementioned heating component 135 is disposed on the mesa surface on either side of the ridge waveguide structure 117, as Figure 6The target tabletop 1174 shown in []. Similarly, the third groove 1351 and the fourth groove 1352 are located in the area where the target tabletop 1174 is located. Or rather, the third groove 1351 and the fourth groove 1352 pass through the target tabletop 1174 in the direction opposite to the epitaxial growth direction X, and one side opening of the third groove 1351 and the fourth groove 1352 is on the same plane as the target tabletop 1174.

[0092] Furthermore, based on the structure shown in Figure 6 , 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. Or, from the perspective of the manufacturing process, the third groove 1351 and the fourth groove 1352 are both obtained by etching. Therefore, from the direction opposite to the epitaxial growth direction X, the third groove 1351 and the fourth groove 1352 start etching from the target tabletop 1174 and etch to a certain position in the first cladding layer 116. It can also be understood that 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 added that in some feasible solutions, from the perspective of the manufacturing process, the ridge waveguide structure 117 can also be obtained by etching, and it starts etching from the original cover layer (i.e., the cover layer before etching) until it 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 part of the body of the first cladding layer 116. In this case, the depths of the third groove 1351 and the fourth groove 1352 should be less than the height of the unetched part of the body of the first cladding layer 116.

[0094] In addition, as shown in Figure 6 (a) of [], the laser 100 may further include a fifth electrode layer 118 and a fourth electrode layer 134. Among them, 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 can be used to access the excitation electrical signal, and this excitation electrical signal is used for the normal operation of the laser 100.

[0095] In an alternative implementation, based on the structure shown in Figures 4 - 6 , please refer to Figure 7 , Figure 7 is another schematic structural diagram of a laser provided by this application. As shown in Figure 7As shown, the heating component 135 may include a thin-film metal resistor 1353, and a first electrode 1354 and a second electrode 1355 respectively connected to both 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 realizing heating of the second grating region 1102 to change the refractive index of the second grating region 1102.

[0097] In the above implementation, using the thin-film metal resistor 1353 as the heating component 135, the solution is simple and easy to implement, and the cost of the laser 100 can be reduced.

[0098] It should be noted here that in actual implementation, the heating component 135 can also be implemented in other possible ways, as long as it can be applied 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 implementation manners, the initial phase of the laser 100 provided in this 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]

[0102] Wherein, P is the initial phase and L is the first length.

[0103] Furthermore, when the initial phase, the first grating period S1, the second grating period S2, and the first length satisfy the foregoing formula (1), for the laser 100 provided in this 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 bandgap 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 a preset difference. Here, the preset difference should be less than or equal to 0.1π. The above second phase value is the phase value corresponding to the upper limit or the lower limit of the transmission bandwidth of the grating structure.

[0104] That is to say, for the laser 100 provided in this application, the initial phase can 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 bandgap 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 the lower limit of the transmission bandwidth of the grating structure. Combining the previous explanation of the continuous frequency-sweeping function, it can be known that the bandgap of the grating structure will continuously move within the transmission bandwidth of the grating structure with a period of 2π. If the design makes the initial phase value corresponding to the bandgap of the grating structure as close as possible to the phase value corresponding to the upper limit or the lower limit of the transmission bandwidth of the grating structure, the movable range of the bandgap of the grating structure can be made larger. In this way, when the laser 100 realizes the continuous frequency-sweeping function, its frequency-sweeping range will become larger, and the frequency-sweeping bandwidth of the laser 100 can be improved.

[0105] It should be noted that the above target phase is an empirical value obtained by conducting multiple experiments on the laser 100 provided in this application, which can make the bandgap of the grating structure as close as possible to the upper limit or the lower limit of the transmission bandwidth of the grating structure. Since the value of the target phase will change with the change of the first length described above, this application does not specifically limit the value of the target phase. Exemplarily, the initial phase P is generally set at a position that ensures single-mode lasing of the laser 100, such as any position between 0.6π and 0.8π.

[0106] It should also be noted that since there are two moving directions of the bandgap of the grating structure within the transmission bandwidth of the grating structure, for the laser provided in this application, the bandgap of the grating structure is made to approach the upper limit or the lower limit in the transmission bandwidth that is opposite to its moving direction by designing the initial phase P. That is to say, when the bandgap of the grating structure moves from 0 to 2π, the design should make the bandgap of the grating structure approach the lower limit of the transmission bandwidth. When the bandgap of the grating structure moves from 2π to 0, the design should make the bandgap of the grating structure approach the upper limit of the transmission bandwidth.

[0107] In some feasible implementation manners, please refer to Figure 8 , Figure 8 is another schematic structural diagram of a laser provided in this application. As shown in (a) of Figure 8 , anti-reflection (AR) films 1193 and high-reflection (HR) films 1194 are respectively deposited on the cavity surfaces of the laser 100 in the cavity length direction Y. Specifically, as shown in Figure 8As shown, an AR film 1193 is deposited on the first cavity surface 1191 of the laser 100 in the cavity length direction Y, and an HR film 1194 is deposited on the second cavity surface 1192 of the laser 100 in the cavity length direction Y, respectively. 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 exit 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.

[0108] As Figure 8 shown in (b) of Figure 8 As shown, an AR film 1193 is deposited on the first cavity surface 1191 of the laser 100 in the cavity length direction Y, and an AR film 1195 is deposited on the second cavity surface 1192 of the laser 100 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 wave generated by the laser 100 will exit from the first cavity surface 1191 and the second cavity surface 1192 simultaneously. 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.

[0109] In some feasible implementation manners, 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 beneficial to realizing a narrower linewidth output and lower relative intensity noise of the laser 100. In actual implementation, the complex-coupled grating layer at least includes a grating layer doped with N-type with a high refractive index and carrier inversion and a grating layer doped with P-type with a high refractive index. During actual operation, the grating layer located below will generate a periodic refractive index modulation, and the upper doping inversion material layer will generate a large carrier concentration difference in the inversion layer when current is injected, introducing optical loss and thus modulating the imaginary part of the refractive index to form gain coupling. Therefore, the complex-coupled grating structure can introduce a negative feedback effect, which can reduce the effective linewidth enhancement factor, thus being beneficial to realizing a narrower linewidth output and lower relative intensity noise of the laser 100.

[0110] Exemplarily, please refer to Figure 9 , Figure 9 which is a schematic structural diagram of a grating layer provided in the present application. As Figure 9 shown, the grating layer 110 may include a first sub-grating layer 1104 and a second sub-grating layer 1105 sequentially arranged in the epitaxial growth direction X, and the first sub-grating layer 1104 is doped with N-type, and the second sub-grating layer 1105 is doped with P-type.

[0111] In some feasible implementation manners, please refer toFigure 10 , Figure 10 is another structural schematic diagram of a laser provided by this application. As Figure 10 shown, 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 in the figure) may also be included, and this etch stop layer is usually disposed between the first cladding layer 116 and the filling layer 111. Among them, 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. In the case of Figure 10 the structure shown, the laser 100 may also be referred to as a sandwich-type MQW semiconductor laser.

[0112] It should be noted that this application does not limit the specific materials of the various layer structures included in the epitaxial structure 11, as long as it can achieve the functions of the epitaxial structure 11 provided by this application.

[0113] Furthermore, it should be noted that Figure 10 in the structure shown, the grating layer 110 is disposed on the side of the MQW layer 123 facing away from the substrate layer 112, or rather, the grating layer 110 is disposed above the first barrier layer 121.

[0114] In practical applications, the grating layer 110 may also be disposed between the MQW layer 123 and the substrate layer. Specifically, it may be disposed below the second barrier layer 125. That is to say, the grating layer 110 can be prepared as a bottom grating, which can optimize the square distribution and thus reduce the internal loss of the laser 100.

[0115] In some feasible implementation manners, on the basis of the Figure 10 structure shown, please refer to Figure 11 , Figure 11 is another structural schematic diagram of a laser provided by this application. As Figure 11As shown, a first cavity 1281 may be provided in the active layer 128. The first cavity 1281 penetrates the active layer 128 in the epitaxial growth direction X. That is to say, one end face of the first cavity 1281 is located on the contact surface between the first blocking layer 121 and the spacer layer 120, and the other end face is located on the contact surface between the second blocking layer 125 and the buffer layer 126. Moreover, the first cavity 1281 and the second grating region 1102 are oppositely arranged in the epitaxial growth direction Y. In other words, in the opposite direction of the epitaxial growth direction Y, the projection parts or all of the first cavity 1281 and the second grating region 1102 on the substrate layer 112 coincide. In addition, a bulk material waveguide 1282 is filled in the first cavity 1281. Here, the so-called bulk material waveguide can also be called a bulk passive waveguide (BPW).

[0116] It should be noted that the length of the first cavity 1281 in the direction perpendicular to the cavity length direction Y may be less than or equal to the width of the epitaxial structure 11. That is to say, in actual implementation, the parts of the active layer on both sides of the first cavity 1281 may be unconnected or connected, and this application does not limit this.

[0117] In the above implementation, by providing the first cavity 1281 in the active layer 128 and filling it with the bulk material waveguide 1282, the second grating region 1102 can only play the role of adjusting the refractive index in the cavity without generating gain, which is beneficial to the performance stability of the laser 100.

[0118] Optionally, the first effective refractive index of the bulk material waveguide 1282 matches the second effective refractive index of the parts of the active layer on both sides of the first cavity 1281. Here, the parts of the active layer on both sides of the first cavity 1281 can be understood as the parts of the main body of the active layer 128 around the first cavity 1281.

[0119] Furthermore, the matching of the first effective refractive index of the bulk material waveguide 1282 and the second effective refractive index of the part of the active layer can be understood as that the mode field spot areas calculated from the two effective refractive indices are equal.

[0120] In some feasible implementation manners, the laser 100 provided by 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.

[0121] It should also be supplemented that for the laser 100 provided by this application, it should be designed as much as possible to make the length of the second grating region 1102 larger, because the larger the length of the second grating region 1102, the smaller the refractive index change amount required for the control of the laser 100, and the corresponding power consumption is also smaller.

[0122] Embodiments of the present application also provide a laser array. Please refer to Figure 12 , Figure 12 which is a schematic structural diagram of a laser array provided by the present application. As Figure 12 shown, the laser array 300 may include at least two lasers 100 provided by the present application.

[0123] In actual operation, the laser array 300 emits at least two light waves simultaneously through these two lasers 100.

[0124] It should be understood that Figure 12 this is only illustrative. In actual implementation, the laser array 300 may also include other components, such as a power supply, a control circuit, etc., which are not elaborated in the present application.

[0125] Embodiments of the present application also provide an optical device. Please refer to Figure 13 , Figure 13 which is a schematic structural diagram of an optical device provided by the present application. As Figure 13 shown, the optical device 500 may include the laser 100 or the laser array 300 described above.

[0126] In actual operation, the laser 100 or the laser array 300 described above is used to provide the required light waves for the optical device 500.

[0127] Optionally, the optical device 500 may specifically be an OLT or an ONU.

[0128] It should be understood that Figure 13 this is also only illustrative. In actual implementation, the optical device 500 may also include other components, such as a power supply, a controller, an optical module, etc., which are not elaborated in the present application.

[0129] The terms "first", "second", "third", "fourth", etc. in the description, claims, and drawings of the present application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally further include steps or units not listed, or may optionally further include other steps or units inherent to these processes, methods, products, or devices.

[0130] Reference to "embodiments" in this specification means that the particular features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment each time, nor is it an independent or alternative embodiment mutually exclusive of other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0131] The specific implementation manners described above further elaborate on the purpose, technical solutions, and beneficial effects of the present application. It should be understood that the above are only specific implementation manners of the present application and are not used to limit the protection scope of the present application. Any modifications, equivalent replacements, improvements, etc. made on the basis of the technical solutions of the present application shall be included in the protection scope of the present application.

Claims

1. A laser, characterized in that, The laser includes an epitaxial structure and a phase control component. The grating layer in the epitaxial structure includes a first grating region, a second grating region, and a third grating region arranged in sequence in the cavity length direction of the laser. The first grating period corresponding to the second grating region is greater than the second grating period corresponding to the first grating region and the third grating region. During the process of the laser emitting light waves, the phase control component is used to control the in-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, wherein The laser includes a first electrode layer, a second electrode layer, and a third electrode layer disposed on the first surface of the epitaxial structure, and a fourth electrode layer disposed on the second surface of the epitaxial structure. The first surface is 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 is disposed opposite to the first grating region in the epitaxial growth direction of the epitaxial structure, the second electrode layer is disposed opposite to the second grating region in the epitaxial growth direction, the third electrode layer is disposed opposite to the third grating region in the epitaxial growth direction, a first groove is provided between the first electrode layer and the second electrode layer, and a second groove is provided 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 the excitation electrical signals applied to the second electrode layer and the fourth electrode layer.

3. The laser according to claim 2, wherein The depths of the first groove and the second groove in the epitaxial growth direction are both equal to or greater than the thickness of the cover layer, and less than the sum of the thickness of the cover layer and the thickness of the first cladding layer in the epitaxial structure that is in contact with the cover layer 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 includes a first ridge waveguide region, a second ridge waveguide region, and a third ridge waveguide region arranged in sequence in the cavity length direction divided by the first groove and the second groove. The first surface at least includes 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 and the mesa 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 a first part of the body of the second electrode layer is disposed on the surface of the second ridge waveguide region facing away from the grating layer, and a second part of the body of the second electrode layer other than the first part is disposed on the mesa on both sides of the second ridge waveguide region.

5. The laser according to claim 1, wherein The phase control component includes a heating component. The heating component is disposed on the first surface of the epitaxial structure. The heating component is close to the second grating region. The first surface is on the 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 an applied excitation electrical signal, so as 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 cavity length direction is less than or equal to the first length of the second grating region in the cavity length direction.

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, and the third groove, the heating component, and the fourth groove are arranged in sequence in the cavity length direction; The third groove is used to block the heat of the heating component from propagating to the first grating region, and the fourth groove is used to block the heat of the heating component from propagating to the third grating region.

8. The laser according to any one of claims 5-7, characterized in that, The epitaxial structure further includes a ridge waveguide structure. The first surface includes a third surface of the ridge waveguide structure facing away from the grating layer and mesa surfaces on both sides of the ridge waveguide structure. The heating component is disposed on a target mesa surface on either side of the ridge waveguide structure, and the third groove and the fourth groove are located in the region where the target mesa 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 less than the thickness of the first cladding layer in the epitaxial structure that is in contact with the cover layer.

10. The laser according to any one of claims 5-9, characterized in that, The heating component includes a thin-film metal resistor and a first electrode and a second electrode respectively connected to both 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 region under the action of the excitation electrical signal applied to the first electrode and the second electrode.

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

12. The laser according to claim 11, wherein, The initial phase of the laser is a preset target phase. The difference between the first phase value corresponding to the bandgap of the grating structure in the epitaxial structure and the second phase value corresponding to the transmission bandwidth of the grating structure is less than or equal to a preset difference. The second phase value is the phase value corresponding to the upper limit or the lower limit of the transmission bandwidth of the grating structure. The grating structure includes the grating layer and the 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: Where 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 11-13, characterized in that, Anti-reflection films and high-reflection films are respectively coated on the cavity surfaces of the laser in the cavity length direction. 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 is doped with N-type, and the second sub-grating layer is doped with P-type.

16. The laser according to any one of claims 1-15, characterized in that, 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 is oppositely arranged with the second grating region in the epitaxial growth direction, and the first cavity is filled with a bulk material waveguide.

17. The laser according to claim 16, wherein, The first effective refractive index of the bulk material waveguide matches the second effective refractive index of the partial active layers located on both sides of the first cavity.

18. The laser according to any one of claims 1-17, 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 includes at least two lasers according to any one of claims 1-18.

20. An optical device, characterized in that, The optical device includes a laser according to any one of claims 1-18, or includes a laser array according to claim 19.

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