Tunable laser and optical semiconductor element

Abstract

The application relates to a tunable laser, which comprises a channel selection component, a plurality of optical amplifiers, a micro-ring filter component and a reflection component, the micro-ring filter component is coupled with the reflection component, and the working wavelength range of each optical amplifier is different; wherein: the channel selection component is used for selecting any optical amplifier to input a gain optical signal into the micro-ring filter component; the micro-ring filter component is used for filtering the gain optical signal under a vernier effect to obtain a filtered optical signal and then inputting the filtered optical signal into the reflection component; and the reflection component is used for outputting part of the filtered optical signal to the outside and reflecting the other part of the filtered optical signal to the optical amplifier currently selected by the channel selection component after the other part of the filtered optical signal passes through the micro-ring filter component. The wavelength range of the laser tuning of the application is large.

Description

Technical Field

[0001] This invention relates to the field of laser technology, and in particular to a tunable laser and an optical semiconductor element. Background Technology

[0002] With the development of laser technology, silicon photonic chips have gained increasing attention in data centers, optical interconnects, and other fields due to their advantages such as small size and ease of integration, and are widely regarded as a key technology in next-generation networks. Among these, increasing the laser tuning wavelength range of silicon photonic chips has become a key research issue in order to enable scanning over a large free spectral range.

[0003] In related technologies, tunable lasers include a gain chip and a dual micro-ring resonator. The gain chip is coupled to the dual micro-ring resonator, and laser tuning of the tunable laser is achieved through the vernier caliper effect of the dual micro-ring resonator within the gain bandwidth of the gain chip.

[0004] However, since the gain bandwidth of a single gain chip is limited, the wavelength range of laser tuning for tunable lasers is relatively small, making it impossible to further increase the free spectral range of silicon photonics chips during scanning. Summary of the Invention

[0005] Therefore, it is necessary to provide a tunable laser and optical semiconductor element to address the problem of the limited wavelength range of laser tuning mentioned above.

[0006] In a first aspect, the present invention provides a tunable laser, comprising a channel selection component, a plurality of optical amplifiers, a micro-ring filter component, and a reflection component, wherein the micro-ring filter component is coupled to the reflection component, and each of the optical amplifiers has a different operating wavelength range; wherein:

[0007] The channel selection component is used to select any optical amplifier to input a gain optical signal to the micro-ring filter component;

[0008] The micro-ring filter component is used to filter the gain optical signal under the vernier caliper effect to obtain a filtered optical signal, which is then input into the reflection component.

[0009] The reflection component is used to output a portion of the filtered optical signal outward, and to reflect another portion of the optical signal, after passing through the micro-ring filter component, to the optical amplifier currently selected by the channel selection component.

[0010] In one embodiment, the channel selection component includes a switch controller connected to a plurality of optical amplifiers; the micro-ring filter component includes a plurality of micro-ring filter components coupled to a plurality of optical amplifiers; wherein:

[0011] The switch controller is used to control any optical amplifier to be turned on and to input a drive electrical signal to the turned-on optical amplifier;

[0012] The optical amplifier is used to output a gain optical signal to the micro-ring filter component coupled thereto under the drive of the driving electrical signal.

[0013] In one embodiment, the channel selection component includes a first optical switch, which has two first input terminals and one first output terminal. The two first input terminals of the first optical switch are respectively connected to the two optical amplifiers, and the first output terminal is connected to the micro-ring filter component, wherein:

[0014] The first optical switch is used to control one of the optical amplifiers to input a gain optical signal to the micro-ring filter component.

[0015] In one embodiment, the tunable laser further includes a first phase shifter connected to the optical amplifier and coupled to the micro-ring filter assembly; each of the optical amplifiers includes a semiconductor optical amplifier with a high reflectivity; wherein:

[0016] The reflection component is used to reflect a portion of the filtered optical signal to the high-reflection surface of the semiconductor optical amplifier after passing through the micro-ring filter component, and together with the semiconductor optical amplifier, it forms a characteristic resonant cavity.

[0017] The first phase shifter is used to adjust the resonant wavelength of the characteristic resonant cavity to be the same as the resonant wavelength of the micro-ring filter component.

[0018] In one embodiment, the microring filter assembly includes a first microring resonant cavity and a second microring resonant cavity, the first and second microring resonant cavities having different sizes but the same resonant wavelength; the first microring resonant cavity is coupled to the semiconductor optical amplifier and the second microring resonant cavity respectively, and the second microring resonant cavity is coupled to the reflection assembly, wherein:

[0019] The first microring resonator and the second microring resonator together generate a vernier caliper effect to filter the gain optical signal;

[0020] The first phase shifter is used to adjust the resonant wavelength of the characteristic resonant cavity to be the same as the resonant wavelength of the first micro-ring resonant cavity and the second micro-ring resonant cavity.

[0021] In one embodiment, the first microring resonant cavity includes a first microring and a second phase shifter connected to the first microring, and the second microring resonant cavity includes a second microring and a third phase shifter connected to the second microring, wherein the first microring and the second microring have different sizes; wherein:

[0022] The second phase shifter is used to adjust the resonant wavelength of the first microring;

[0023] The third phase shifter is used to adjust the resonant wavelength of the second microring to be the same as the resonant wavelength of the first microring.

[0024] In one embodiment, the reflective component includes a mutually coupled light reflector and a first optical coupler, the light reflector being coupled to the micro-ring filter component, the first optical coupler including a second output terminal and a third output terminal, and the first optical coupler being coupled to the micro-ring filter component, wherein:

[0025] The light reflector is used to input the filtered light signal to the first optical coupler;

[0026] The first optical coupler is used to output a portion of the filtered optical signal to the outside through the second output terminal, and to reflect another portion of the filtered optical signal to the micro-ring filter component through the third output terminal.

[0027] In one embodiment, each of the optical amplifiers includes a semiconductor optical amplifier with a high reflectivity, wherein the reflective component and the high reflectivity of the semiconductor optical amplifier together constitute a characteristic resonant cavity;

[0028] The coupling coefficient of the first optical coupler is a preset proportional threshold; wherein the proportional threshold is set in relation to the loss of the characteristic resonant cavity and the reflected light intensity of the characteristic resonant cavity on the semiconductor optical amplifier.

[0029] In one embodiment, the first optical coupler includes a second optical switch having two adjustment arms, wherein:

[0030] The second optical switch is used to adjust the coupling coefficient of the first optical coupler by adjusting the splitting ratio of the two adjustment arms.

[0031] In one embodiment, the integration method of the tunable laser includes, but is not limited to, heterogeneous integration or hybrid integration.

[0032] In the aforementioned tunable laser, a channel selection component selects any optical amplifier to input a gain optical signal to a micro-ring filter component. The gain optical signal is filtered by the micro-ring filter component and input to a reflection component. The reflection component outputs a portion of the optical signal outward and reflects the other portion of the optical signal sequentially through the micro-ring filter component and the channel selection component back into the optical amplifier. The reflection component and the optical amplifier together form a resonant cavity, thereby achieving laser tuning. In the above structure, multiple optical amplifiers correspond to different gain wavelength ranges. The channel selection component enables the alternating use of multiple optical amplifiers, effectively increasing the wavelength range for laser tuning of the tunable laser.

[0033] Secondly, the present invention also provides an optical semiconductor element on which the above-mentioned tunable laser is integrated.

[0034] In the aforementioned optical semiconductor, by setting up the tunable laser, it is possible to increase the wavelength range of laser tuning. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 A schematic diagram of a tunable laser module as one implementation;

[0037] Figure 2 A schematic diagram of the structure of a tunable laser according to one embodiment;

[0038] Figure 3 A schematic diagram of the reflection spectrum of an optical amplifier for a micro-ring filter component according to one embodiment;

[0039] Figure 4 This is a schematic diagram of a tunable laser according to another embodiment. Specific Implementation

[0040] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0041] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a number" means one or more, and "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. The meanings of "multiple groups," "multiple paths," and "multiple bundles" are similar and will not be elaborated further here.

[0042] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0043] It should be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0044] Please see Figure 1 As shown, the present invention provides a tunable laser 100, which includes a plurality of optical amplifiers 10, a channel selection component 20, a micro-ring filter component 30, and a reflection component 40.

[0045] Multiple optical amplifiers 10 with different operating wavelength ranges are connected in parallel to the channel selection component 20. The channel selection component 20 is coupled to the micro-ring filter component 30, which in turn is coupled to the reflection component 40.

[0046] in:

[0047] Optical amplifier 10 is used to amplify the gain of an optical signal to output a gained optical signal. It is worth mentioning that the number of optical amplifiers 10 is unlimited. For example, in some embodiments, there are two optical amplifiers 10, and the gain wavelength ranges (i.e., operating wavelength ranges) of the two optical amplifiers 10 are adjacent to each other.

[0048] The channel selection component 20 is used to select any one of the optical amplifiers 10 to input a gain optical signal to the micro-ring filter component 30. Specifically, the channel selection component 20 selects one of the optical amplifiers 10 to couple with the micro-ring filter component 30, and each optical amplifier 10 can input a gain optical signal to the micro-ring filter component 30 within its operating wavelength range. By alternately selecting multiple optical amplifiers 10 through the channel selection component 20, laser adjustment is achieved within different wavelength ranges. For example, in some embodiments, there are two optical amplifiers 10. When the channel selection component 20 controls one of the optical amplifiers 10 to couple with the micro-ring filter component 30, it can be understood that the selected optical amplifier 10 is in an "on" state, and current is injected into it to generate a gain optical signal within its operating wavelength range, while the other unselected optical amplifier 10 is in a "off" state, and no current is injected into it, thus no gain optical signal is generated. In addition, since the operating wavelength ranges of the two optical amplifiers 10 are adjacent, laser tuning can be achieved in a large and continuous gain wavelength range by setting the channel selection component 20, which effectively increases the wavelength range of laser tuning of the tunable laser 100.

[0049] The micro-ring filter component 30 is used to filter the gain optical signal under the vernier caliper effect to obtain a filtered optical signal, which is then input into the reflection component 40. Specifically, in some embodiments, the optical amplifier 10 includes two, and the channel selection component 20 selects one of the optical amplifiers 10 to be turned on. At this time, the micro-ring filter component 30 can filter within the operating wavelength range of the selected optical amplifier 10. This is equivalent to the micro-ring filter component 30 being a chip equivalent to a wavelength-selective reflector. The gain optical signal within the operating wavelength range of the selected optical amplifier 10 is input into the reflection component 40, and the optical signal outside the operating wavelength range of the selected optical amplifier 10 is filtered out, thereby achieving the filtering of the gain optical signal.

[0050] The reflective component 40 is used to output a portion of the filtered optical signal as an output optical signal; and to reflect another portion of the optical signal, after passing through the micro-ring filter component 30, to the optical amplifier 10 currently selected by the channel selection component 20, so that this portion of the optical signal returns to the optical amplifier 10 along the original path as a reflected optical signal. The reflective component 40 and the optical amplifier 10 together constitute a laser resonant cavity, thereby achieving laser tuning. Specifically, in some embodiments, there are two optical amplifiers 10, and each optical amplifier 10 and the reflective component 40 form a laser resonant cavity. Here, it is equivalent to two laser resonant cavities sharing one reflective component 40, and the reflection directions of the two laser resonant cavities in the reflective component 40 are opposite.

[0051] In the aforementioned tunable laser 100, multiple optical amplifiers 10 correspond to different operating wavelength ranges. The channel selection component 20 enables the alternating use of multiple optical amplifiers 10, thereby achieving laser tuning within a large and continuous gain wavelength range and effectively increasing the laser tuning wavelength range of the tunable laser 100.

[0052] It should be noted that the structural form of the channel selection component 20 is not limited. For ease of understanding, the following explanation will be provided with reference to different accompanying drawings, but the structural form of the channel selection component 20 is not limited to these. Specifically:

[0053] like Figure 2 As shown, in some embodiments, the channel selection component 20 includes a switch controller 21, which is connected to multiple optical amplifiers 10; the micro-ring filter component 30 includes multiple components, each of which is coupled to the reflection component 40 via an optical waveguide. The multiple optical amplifiers 10 are respectively coupled one-to-one with each of the multiple micro-ring filter components 30 via optical waveguides. Wherein:

[0054] The switch controller 21 is used to control any one of the optical amplifiers 10 to be turned on and to input a driving electrical signal to the turned-on optical amplifier 10. Specifically, the input terminal of the switch controller 21 is connected to the power supply, and the output terminal of the switch controller 21 is electrically connected to multiple optical amplifiers 10 respectively. For example, in some embodiments, the power supply is a DC power supply, and the output terminal of the switch controller 21 is connected to optical amplifiers RSOA1 and RSOA2 respectively. The switch controller 21 is used to control the optical amplifiers RSOA1 or RSOA2 to be turned on or off. When the switch controller 21 controls the optical amplifier RSOA1 to be turned on, it simultaneously controls the optical amplifier RSOA2 to be turned off. Then, the driving electrical signal of the power supply is input to RSOA1 through the switch controller 21 to input the driving electrical signal. Conversely, the same applies when the switch controller 21 controls the optical amplifier RSOA2 to be turned on. This will not be elaborated further here.

[0055] Optical amplifier 10 is used to output a gain optical signal to the micro-ring filter component 30 coupled thereto under the drive of a driving electrical signal. Specifically, in some embodiments, when optical amplifier RSOA1 is turned on, it outputs a gain optical signal to the micro-ring filter component 30 coupled thereto within a first operating wavelength range under the drive of a driving electrical signal; and when optical amplifier RSOA2 is turned on, it outputs a gain optical signal to the micro-ring filter component 30 coupled thereto within a second operating wavelength range under the drive of a driving electrical signal.

[0056] In the above embodiments, by setting the switch controller 21, the on and off control of multiple optical amplifiers 10 can be realized, thereby avoiding the phenomenon of optical signal interference caused by different optical amplifiers 10 outputting gain signals at the same time, which is beneficial to improving the stability of the optical scanning signal finally output by the tunable laser 100.

[0057] like Figure 4 As shown, in some embodiments, the channel selection component 20 includes a first optical switch 22, which includes two first input terminals and one first output terminal. The two first input terminals of the first optical switch 22 are respectively connected to two optical amplifiers 10, and the first output terminal is connected to the micro-ring filter component 30, wherein:

[0058] The first optical switch 22 is used to control one of the optical amplifiers 10 to input a gain optical signal to the micro-ring filter component 30.

[0059] Specifically, in some embodiments, the first optical switch 22 is an optical switch composed of a Mach-Zehnder interferometer (MZI). The two first input terminals of the first optical switch 22 are coupled to optical amplifier RSOA1 and optical amplifier RSOA2, respectively. When the first input terminal connected to optical amplifier RSOA1 is turned on by controlling the first optical switch 22, the gain optical signal of optical amplifier RSOA1 is input to micro-ring filter component 30 through the first output terminal of the first optical switch 22. When the first input terminal connected to optical amplifier RSOA2 is turned on, the gain optical signal of optical amplifier RSOA2 is input to micro-ring filter component 30 through the first output terminal of the first optical switch 22.

[0060] In the above embodiments, by setting the first optical switch 22, multiple optical amplifiers 10 can share a micro-ring filter component 30, which can better simplify the structure of the tunable laser 100.

[0061] like Figure 2 As shown, in some embodiments, the tunable laser 100 further includes a first phase shifter 50, which is connected to the optical amplifier 10 and coupled to the micro-ring filter assembly 30; each optical amplifier 10 includes a high-reflectivity semiconductor optical amplifier (RSOA, short for Reflective Semiconductor Optical Amplifier). Wherein:

[0062] The reflective component 40 is a circular reflector, which is used to reflect a portion of the filtered optical signal after it passes through the micro-ring filter component 30 to the high-reflection surface of the semiconductor optical amplifier. The reflective component 40 and the semiconductor optical amplifier together constitute a characteristic resonant cavity.

[0063] The first phase shifter 50 is used to adjust the resonant wavelength of the characteristic resonant cavity to be the same as the resonant wavelength of the micro-ring filter component 30, so that the optical signal reflected from the reflector component 40 can be incident on the high-reflection surface of the semiconductor optical amplifier through the first phase shifter 50. Specifically, the first phase shifter 50 includes, but is not limited to, a phase shifter composed of an SOI silicon-based optical waveguide and a PIN junction diode, and a phase shifter composed of an SOI silicon-based optical waveguide and a metal heater. The first phase shifter 50 is used to perform phase modulation using the electro-optic effect of the PIN junction diode, or to perform phase modulation using thermal modulation of the metal electrode, to achieve high-speed phase modulation. The phase modulation speed can reach the GHz (gigahertz, or gigahertz) level, which is beneficial for improving the spectral scanning efficiency of the tunable laser 100.

[0064] Furthermore, in some embodiments, the micro-ring filter assembly 30 includes a first micro-ring 311 resonant cavity 31 and a second micro-ring 321 resonant cavity 32, wherein the first micro-ring 311 resonant cavity 31 and the second micro-ring 321 resonant cavity 32 have different sizes but the same resonant wavelength.

[0065] Specifically, the first micro-ring 311 resonant cavity 31 is coupled to the semiconductor optical amplifier, and the first micro-ring 311 resonant cavity 31 and the second micro-ring 321 resonant cavity 32 are coupled to form a cascaded micro-ring structure, while the second micro-ring 321 resonant cavity 32 is also coupled to the reflective component 40, wherein:

[0066] The first micro-ring 311 resonant cavity 31 and the second micro-ring 321 resonant cavity 32 together generate a vernier caliper effect to filter the gain optical signal.

[0067] The first phase shifter 50 is used to adjust the resonant wavelength of the characteristic resonant cavity to be the same as the resonant wavelength of the first micro-ring 311 resonant cavity 31 and the second micro-ring 321 resonant cavity 32, so that the light signal reflected from the reflective component 40 can be incident on the high reflection side of the semiconductor optical amplifier through the first phase shifter 50.

[0068] To further understand the working principle of the micro-ring filter component 30, more specifically, in some embodiments, the first micro-ring 311 resonant cavity 31 includes a first micro-ring 311 and a second phase shifter 312 connected to the first micro-ring 311, and the second micro-ring 321 resonant cavity 32 includes a second micro-ring 321 and a third phase shifter 322 connected to the second micro-ring 321. The first micro-ring 311 and the second micro-ring 321 have different sizes, and the first micro-ring 311 and the second micro-ring 321 together constitute a cascaded micro-ring structure. This cascaded micro-ring structure can produce a vernier caliper effect. Wherein:

[0069] The second phase shifter 312 is used to adjust the resonant wavelength of the first micro-ring 311; the third phase shifter 322 is used to adjust the resonant wavelength of the second micro-ring 321 to be the same as the resonant wavelength of the first micro-ring 311. It is worth mentioning that the structure and working principle of the second and third phase shifters 322 are the same as those of the first phase shifter 50, and will not be described in detail here.

[0070] Please also refer to Figure 3 As shown, Figure 3 The reflection spectrum of the cascaded microring structure (i.e., the first microring 311 resonant cavity 31 and the second microring 321 resonant cavity 32) to the optical amplifier 10 under the vernier caliper effect is shown. It can be seen that there is only one highest resonance peak within a 100nm bandwidth. By adjusting the first phase shifter 50 between the optical amplifier 10 (RSOA1 or RSOA2) and the reflecting component 40, the longitudinal mode of the characteristic resonant cavity formed by the optical amplifier 10 and the reflecting component 40 coincides with this resonance peak, thereby achieving efficient single-wavelength laser output. By adjusting the second phase shifter 312 on the first microring 311 resonant cavity 31 and the third phase shifter 322 on the second microring 321 resonant cavity 32, the resonant wavelengths of the first and second microrings are shifted, and the resonant wavelengths of the first and second microrings are made to be consistent. Utilizing the vernier caliper effect, the resonance peak of the cascaded microring structure can be tuned across the entire bandwidth, achieving a large free spectral range.

[0071] In the above structure, continuous wavelength tuning across the entire wavelength band can be achieved by simultaneously adjusting the first, second, and third phase shifters.

[0072] In some embodiments, the reflective component 40 includes a light reflector 41 and a first optical coupler 42 coupled to each other. The light reflector 41 is coupled to the micro-ring filter component 30. The first optical coupler 42 includes a second output terminal and a third output terminal. The first optical coupler 42 is coupled to the micro-ring filter component 30, wherein:

[0073] The light reflector 41 is used to input the filtered light signal to the first optical coupler 42;

[0074] The first optical coupler 42 is used to output a portion of the filtered optical signal to the outside through the second output terminal, and to reflect another portion of the filtered optical signal to the micro-ring filter component 30 through the third output terminal.

[0075] Furthermore, in some embodiments, each optical amplifier 10 includes a semiconductor optical amplifier with a high reflectivity, and the reflective component 40 and the high reflectivity of the semiconductor optical amplifier together constitute a characteristic resonant cavity.

[0076] The coupling coefficient of the first optical coupler 42 is a preset proportional threshold; wherein, the proportional threshold is set in relation to the loss of the characteristic resonant cavity and the reflected light intensity of the characteristic resonant cavity on the semiconductor optical amplifier. Specifically, in this embodiment, the first optical coupler 42 is a coupler with a fixed coupling coefficient, that is, when designing the tunable laser 100, the coupling coefficient of the first optical coupler 42 is preset to a proportional threshold, and the aforementioned proportional threshold is jointly determined by the loss of the characteristic resonant cavity and the reflected light intensity of the characteristic resonant cavity on the semiconductor optical amplifier. Here, the light intensity of the optical signal reflected back from the reflecting component 40 to the characteristic resonant cavity needs to be greater than the loss of the entire characteristic resonant cavity and greater than the reflected light intensity of the characteristic resonant cavity on the semiconductor optical amplifier, thereby achieving the effect of enhancing the side-mode rejection ratio.

[0077] Furthermore, in some embodiments, the first optical coupler 42 includes a second optical switch having two adjustment arms, wherein:

[0078] The second optical switch is used to adjust the coupling coefficient of the first optical coupler 42 by adjusting the splitting ratio of the two adjustment arms. Specifically, a phase shifter can be provided in the second optical switch. The phase shifter can adjust the splitting ratio of the two adjustment arms. For example, the phase shifter can adjust the splitting ratio of the two adjustment arms by heating. In this embodiment, the first optical coupler 42 is a coupler with an adjustable coupling coefficient. By adjusting the coupling coefficient of the first optical coupler 42, the loss and gain of the entire characteristic resonant cavity can be balanced, thereby maximizing the light output efficiency of the tunable laser 100.

[0079] It is worth mentioning that the integration methods of tunable lasers include, but are not limited to, heterogeneous integration or hybrid integration.

[0080] For example, when the channel selection component includes a switch controller, in some embodiments, the tunable laser is integrated heterogeneously, where the micro-ring filter component and the reflection component are integrated together on the same silicon photonic chip, while the switch controller is located outside the silicon photonic chip; in other embodiments, the tunable laser is integrated hybridally, where the micro-ring filter component, the reflection component, and the switch controller are integrated together on the same silicon photonic chip, where the optical amplifier is located outside the silicon photonic chip. This heterogeneous integration uses longitudinal evanescent wave coupling, requiring an edge coupler between the optical amplifier and the micro-ring filter component to achieve coupling between the two. This results in high integration and does not cause reflection of the gain material of the optical amplifier, which helps to ensure the intensity of the optical signal reflected back to the characteristic resonant cavity.

[0081] For example, when the channel selection component includes a first optical switch, in some embodiments, the tunable laser is integrated in a heterogeneous manner, where the micro-ring filter component, the reflection component, and the first optical switch are integrated together on the same silicon photonic chip; in other embodiments, the tunable laser is integrated in a hybrid manner, where the micro-ring filter component, the reflection component, and the first optical switch are integrated together on the same silicon photonic chip, and in this case, the optical amplifier is located outside the silicon photonic chip.

[0082] It is understood that the structure of the optical waveguide in the above embodiments is not limited, and the optical waveguide includes, but is not limited to, at least one of SOI silicon-based optical waveguide, SiN silicon-based optical waveguide and lithium niobate optical waveguide.

[0083] The present invention also provides an optical semiconductor element (not shown), wherein the above-mentioned tunable laser is integrated on the optical semiconductor element (e.g.), which is beneficial to improving the integration of the optical semiconductor element.

[0084] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0085] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A tunable laser, characterized in that, The tunable laser includes a channel selection component, multiple optical amplifiers, a micro-ring filter component, and a reflection component. The micro-ring filter component is coupled to the reflection component, and the operating wavelength ranges of each optical amplifier are different. Wherein: The channel selection component is used to select any optical amplifier to input a gain optical signal to the micro-ring filter component; The micro-ring filter component is used to filter the gain optical signal under the vernier caliper effect to obtain a filtered optical signal, which is then input into the reflection component. The reflection component is used to output a portion of the filtered optical signal outward, and to reflect another portion of the optical signal, after passing through the micro-ring filter component, to the optical amplifier currently selected by the channel selection component. The tunable laser further includes a first phase shifter connected to the optical amplifier and coupled to the micro-ring filter assembly; each of the optical amplifiers includes a semiconductor optical amplifier with a high reflectivity; wherein: The reflection component is used to reflect a portion of the filtered optical signal to the high-reflection surface of the semiconductor optical amplifier after passing through the micro-ring filter component, and together with the semiconductor optical amplifier, it forms a characteristic resonant cavity. The micro-ring filter component includes a first micro-ring resonant cavity and a second micro-ring resonant cavity, the first and second micro-ring resonant cavities having different sizes but the same resonant wavelength; the first micro-ring resonant cavity is coupled to the semiconductor optical amplifier and the second micro-ring resonant cavity respectively, and the second micro-ring resonant cavity is coupled to the reflection component, wherein: The first microring resonator and the second microring resonator together generate a vernier caliper effect to filter the gain optical signal; The first phase shifter is used to adjust the resonant wavelength of the characteristic resonant cavity to be the same as the resonant wavelength of the first micro-ring resonant cavity and the second micro-ring resonant cavity.

2. The tunable laser according to claim 1, characterized in that, The channel selection component includes a switch controller, which is connected to a plurality of optical amplifiers; the micro-ring filter component includes a plurality of micro-ring filter components, which are coupled to a plurality of optical amplifiers; wherein: The switch controller is used to control any optical amplifier to be turned on and to input a drive electrical signal to the turned-on optical amplifier; The optical amplifier is used to output a gain optical signal to the micro-ring filter component coupled thereto under the drive of the driving electrical signal.

3. The tunable laser according to claim 1, characterized in that, The channel selection component includes a first optical switch, which has two first input terminals and one first output terminal. The two first input terminals of the first optical switch are respectively connected to the two optical amplifiers, and the first output terminal is connected to the micro-ring filter component, wherein: The first optical switch is used to control one of the optical amplifiers to input a gain optical signal to the micro-ring filter component.

4. The tunable laser according to claim 1, characterized in that, The first microring resonant cavity includes a first microring and a second phase shifter connected to the first microring; the second microring resonant cavity includes a second microring and a third phase shifter connected to the second microring; the first microring and the second microring have different sizes; wherein: The second phase shifter is used to adjust the resonant wavelength of the first microring; The third phase shifter is used to adjust the resonant wavelength of the second microring to be the same as the resonant wavelength of the first microring.

5. The tunable laser according to any one of claims 1-3, characterized in that, The reflective component includes a mutually coupled light reflector and a first optical coupler. The light reflector is coupled to the micro-ring filter component. The first optical coupler includes a second output terminal and a third output terminal. The first optical coupler is coupled to the micro-ring filter component, wherein: The light reflector is used to input the filtered light signal to the first optical coupler; The first optical coupler is used to output a portion of the filtered optical signal to the outside through the second output terminal, and to reflect another portion of the filtered optical signal to the micro-ring filter component through the third output terminal.

6. The tunable laser according to claim 5, characterized in that, Each of the optical amplifiers includes a semiconductor optical amplifier with a high reflectivity, wherein the reflective component and the high reflectivity of the semiconductor optical amplifier together constitute a characteristic resonant cavity; The coupling coefficient of the first optical coupler is a preset proportional threshold; wherein the proportional threshold is set in relation to the loss of the characteristic resonant cavity and the reflected light intensity of the characteristic resonant cavity on the semiconductor optical amplifier.

7. The tunable laser according to claim 5, characterized in that, The first optical coupler includes a second optical switch having two adjustment arms, wherein: The second optical switch is used to adjust the coupling coefficient of the first optical coupler by adjusting the splitting ratio of the two adjustment arms.

8. The tunable laser according to any one of claims 1-3, characterized in that, The integration method of the tunable laser includes, but is not limited to, heterogeneous integration or hybrid integration.

9. An optical semiconductor element, characterized in that, The tunable laser according to any one of claims 1-8 is integrated on the optical semiconductor element.

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