Coupling adjustment for optical waveguide microcavity

Abstract

An optical waveguide microcavity and a coupling adjustment device therefor. The optical waveguide microcavity comprises a substrate (10), an optical waveguide (20), an optical microcavity (30), and a coupling adjustment structure (40). The optical waveguide (20) is located on one side of the substrate (10). The optical microcavity (30) is located on the side of the substrate (10) where the optical waveguide (20) is arranged, and is located in the same layer as the optical waveguide (20). The coupling adjustment structure (40) comprises a phase change layer (41) located on the side of the optical waveguide (20) away from the substrate (10), and a heating layer (42) located on the side of the phase change layer (41) away from the substrate (10), wherein the heating layer (42) is configured to adjust the temperature of the phase change layer (41). An orthographic projection of the phase change layer (41) on the substrate (10) overlaps with an orthographic projection of a coupling region of the optical waveguide (20) and / or a coupling region of the optical microcavity (30) on the substrate (10).

Description

Optical waveguide microcavity coupling modulation Technical Field

[0001] This application relates to the field of optical technology, and in particular to an optical waveguide microcavity coupling modulation. Background Technology

[0002] Optical microcavities are fundamental components in integrated optics, playing a vital role in fields such as optical interconnects, optical computing, optical sensing, and nonlinear optics. Summary of the Invention

[0003] This application provides an optical waveguide microcavity, comprising: a substrate; an optical waveguide located on one side of the substrate; an optical microcavity located on the side of the substrate where the optical waveguide is disposed, and located in the same layer as the optical waveguide; and a coupling adjustment structure, the coupling adjustment structure comprising a phase change layer located on the side of the optical waveguide or the optical microcavity away from the substrate and a heating layer located on the side of the phase change layer away from the substrate, the heating layer being used to adjust the temperature of the phase change layer; the orthographic projection of the phase change layer on the substrate overlaps with the orthographic projection of the coupling region of the optical waveguide and / or the coupling region of the optical microcavity on the substrate.

[0004] In one embodiment, the optical waveguide microcavity includes an optical waveguide, an optical microcavity, and a coupling adjustment structure. The optical microcavity is located on one side of the optical waveguide. The orthographic projection of the phase change layer of the coupling adjustment structure on the substrate overlaps with the orthographic projection of the coupling region of the optical waveguide on the substrate, or the orthographic projection of the phase change layer on the substrate overlaps with the orthographic projection of the coupling region of the optical microcavity on the substrate.

[0005] In one embodiment, the optical waveguide microcavity includes at least two optical microcavities, an optical waveguide, and multiple coupling adjustment structures. The at least two optical microcavities are located on the same side of the optical waveguide, and the regions enclosed by the orthographic projections of different optical microcavities on the substrate do not overlap. The orthographic projection of the phase change layer of one of the coupling adjustment structures on the substrate overlaps with the orthographic projection of the coupling region of the optical waveguide on the substrate. The orthographic projection of the phase change layer of each of the other coupling adjustment structures on the substrate overlaps with the orthographic projections of the coupling regions of two adjacent optical microcavities in the at least two optical microcavities on the substrate.

[0006] In one embodiment, the optical waveguide microcavity includes at least two optical microcavities, an optical waveguide, and multiple coupling adjustment structures. The at least two optical microcavities are both located on one side of the optical waveguide. The diameters of the at least two optical microcavities decrease sequentially, and the at least two optical microcavities are nested. The orthographic projection of the phase change layer of one of the coupling adjustment structures onto the substrate overlaps with the orthographic projection of the coupling region of the optical waveguide onto the substrate. The orthographic projection of the phase change layer of each of the other coupling adjustment structures onto the substrate also overlaps with the orthographic projection of the coupling regions of the nested at least two optical microcavities onto the substrate.

[0007] In one embodiment, the optical waveguide microcavity includes an optical microcavity, two optical waveguides, and two coupling adjustment structures, with the optical microcavity located between the two optical waveguides; the orthographic projections of the phase change layers of the two coupling adjustment structures onto the substrate overlap with the orthographic projections of the coupling regions of the two optical waveguides onto the substrate.

[0008] In one embodiment, the optical waveguide microcavity includes at least two optical microcavities, two optical waveguides, and multiple coupling adjustment structures. The at least two optical microcavities are located between the two optical waveguides, and the regions enclosed by the orthographic projections of different optical microcavities on the substrate do not overlap. The orthographic projections of the phase change layers of the two coupling adjustment structures on the substrate overlap with the orthographic projections of the coupling regions of the two optical waveguides on the substrate, respectively. The orthographic projections of the phase change layers of the remaining coupling adjustment structures on the substrate overlap with the orthographic projections of the coupling regions of two adjacent optical microcavities on the substrate.

[0009] In one embodiment, the minimum distance between the optical microcavity and the optical waveguide ranges from 0 μm to 5 μm.

[0010] In one embodiment, when there are multiple optical microcavities, the minimum distance between adjacent optical microcavities ranges from 0 μm to 5 μm.

[0011] In one embodiment, the coupling adjustment structure further includes a heating electrode electrically connected to the heating layer.

[0012] In one embodiment, the material of the phase change layer includes germanium telluride, germanium selenide telluride, or germanium antimony selenide telluride.

[0013] This application also provides an optical waveguide microcavity coupling adjustment device, comprising: a phase change layer for adjusting the effective refractive index of an optical waveguide and / or optical microcavity disposed below the phase change layer; and a heating layer disposed above the phase change layer for adjusting the temperature of the phase change layer to change the effective refractive index of the phase change layer.

[0014] In one embodiment, the device further includes a heating electrode connected to the heating layer.

[0015] In one embodiment, the device further includes an embedding layer that encapsulates the phase change layer and the heating layer.

[0016] In one embodiment, the material of the phase change layer includes germanium telluride, germanium selenide telluride, or germanium antimony selenide telluride.

[0017] In one embodiment, the heating layer is made of titanium nitride and aluminum.

[0018] The optical waveguide microcavity provided in this application allows for adjustment of the coupling strength between the optical waveguide and the optical microcavity, or between two optical microcavities, by adjusting the temperature of the heating layer. The optical waveguide microcavity of this application features a simple and compact design with low requirements for processing precision. Adjusting the coupling strength by regulating the refractive index of the phase change layer allows for a wider adjustment range. Furthermore, the phase change layer is non-volatile; once adjusted to a suitable coupling state, it maintains its state even if the external adjustment signal disappears, thus ensuring stable coupling strength within the optical waveguide microcavity.

[0019] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0021] Figure 1 is a partial cross-sectional view of an optical waveguide microcavity provided in an embodiment of this application.

[0022] Figure 2 is a partial cross-sectional view of an optical waveguide microcavity provided in another embodiment of this application.

[0023] Figure 3 is a schematic diagram of the structure of an optical waveguide microcavity provided in an embodiment of this application.

[0024] Figure 4 is a schematic diagram of the structure of an optical waveguide microcavity provided in another embodiment of this application.

[0025] Figure 5 is a schematic diagram of the structure of an optical waveguide microcavity provided in another embodiment of this application.

[0026] Figure 6 is a schematic diagram of the structure of an optical waveguide microcavity provided in an embodiment of this application.

[0027] Figure 7 is a schematic diagram of the structure of an optical waveguide microcavity provided in an embodiment of this application.

[0028] Figure 8 is a schematic diagram of the mode structure of the optical waveguide microcavity before and after adjustment according to an embodiment of this application.

[0029] Figure 9 is a schematic diagram of the mode structure of the optical waveguide microcavity before and after adjustment according to another embodiment of this application.

[0030] Figure 10 is a schematic diagram of the mode structure of the optical waveguide microcavity before and after adjustment according to another embodiment of this application.

[0031] Figure 11 is a schematic diagram of the mode structure of the optical waveguide microcavity before and after adjustment according to an embodiment of this application. Detailed Implementation

[0032] The technical solutions in the embodiments (or "implementations") of this application will be clearly and completely described herein with reference to the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0033] If the embodiments of this application contain terms relating to directional indications or positional relationships (such as up, down, left, right, front, back, inside, outside, top, bottom, center, vertical, horizontal, longitudinal, transverse, length, width, counterclockwise, clockwise, axial, radial, circumferential, etc.), such terms are only used to explain the relative positional relationships and movements between components in a specific posture (as shown in the attached figures); if the specific posture changes, the directional indications or positional relationships will also change accordingly. Furthermore, the terms "first" and "second" used in the embodiments of this application are only for descriptive convenience and should not be construed as indicating or implying relative importance.

[0034] Optical microcavities are fundamental components in integrated optics, playing a crucial role in fields such as optical interconnects, optical computing, optical sensing, and nonlinear optics. Currently, dispersive structures or tunable coupling structures are commonly used to adjust the coupling of optical microcavities. Among these, dispersive structures are complex to design and require high fabrication precision; tunable coupling structures achieve adjustable coupling by changing the spatial relative positions of the microcavity with other optical components, but these structures are relatively large and have a limited adjustment range.

[0035] The optical waveguide microcavity of this application embodiment will be described in detail below with reference to the accompanying drawings. Unless otherwise specified, the features of the following embodiments and implementations can complement or combine with each other.

[0036] An embodiment of this application provides an optical waveguide microcavity, as shown in Figures 1 and 2. The optical waveguide microcavity includes a substrate 10, an optical waveguide 20, an optical microcavity 30, and a coupling adjustment structure 40.

[0037] The optical waveguide 20 is located on one side of the substrate 10. The optical microcavity 30 is located on the side of the substrate 10 where the optical waveguide 20 is located, and is located on the same layer as the optical waveguide 20.

[0038] The coupling adjustment structure 40 includes a phase change layer 41 located on the side of the optical waveguide 20 away from the substrate 10 and a heating layer 42 located on the side of the phase change layer 41 away from the substrate 10. The heating layer 42 is used to adjust the temperature of the phase change layer 41.

[0039] The orthographic projection of the phase change layer 41 on the substrate 10 overlaps with the orthographic projection of the coupling region of the optical waveguide 20 or the coupling region of the optical microcavity 30 on the substrate 10. Alternatively, the orthographic projection of the phase change layer 41 on the substrate 10 overlaps with the orthographic projection of the coupling region of the optical waveguide 20 on the substrate, and also overlaps with the orthographic projection of the coupling region of the optical microcavity 30 on the substrate 10.

[0040] The phase change layer 41 of the coupling adjustment structure 40 contains a phase change material. The phase change material undergoes a phase change with temperature. That is, the crystal structure or molecular arrangement inside the phase change material changes with temperature, thereby changing the physical properties of the phase change material, such as changing the refractive index of the phase change material.

[0041] A phase change layer 41 is disposed near the coupling region of the optical waveguide 20. When the phase change layer 41 undergoes a phase change, its refractive index changes. Because the phase change layer 41 is located around the optical waveguide 20, it effectively affects the refractive index of the surrounding material, resulting in a change in the effective refractive index of the optical waveguide 20. The coupling strength between the optical waveguide 20 and the optical microcavity 30 can be adjusted by regulating the effective refractive index of the optical waveguide 20.

[0042] A phase change layer 41 is disposed near the coupling region of the optical microcavity 30. When the phase change layer 41 undergoes a phase change, its refractive index changes. Since the phase change layer 41 is located around the optical microcavity 30, it effectively affects the refractive index of the surrounding material. This causes changes in the coupling strength between the optical waveguide 20 and the optical microcavity 30 and / or the coupling strength between optical microcavities 30, thereby altering the mode structure of the optical microcavity 30. The coupling structure of the optical microcavity 30 can be adjusted by regulating the coupling strength between the optical waveguide 20 and the optical microcavity 30 and / or the coupling strength between optical microcavities 30.

[0043] It should be noted that the coupling region between the optical waveguide 20 and the optical microcavity 30 refers to the region where their optical fields can effectively interact.

[0044] The heating layer 42 of the coupling adjustment structure 40 can generate heat. This heat is conducted to the phase change layer 41, causing a phase change in the phase change layer 41 and resulting in a change in its refractive index. Therefore, the optical waveguide microcavity of this application can adjust the coupling strength between the optical waveguide 20 and the optical microcavity 30, and / or between optical microcavities 30, by adjusting the temperature of the heating layer 42. The optical waveguide microcavity of this application has a simple design, compact structure, and lower requirements for processing precision. Adjusting the coupling strength by regulating the refractive index of the phase change layer allows for a wider adjustment range. Furthermore, the phase change layer 41 is non-volatile; once adjusted to a suitable coupling state, even if the external adjustment signal (e.g., voltage) disappears, the phase change layer 41 can maintain its state, thus keeping the coupling strength within the optical waveguide microcavity stable.

[0045] Let P0 represent the power in the optical waveguide before coupling, P1 represent the power at the output of the optical waveguide, and P2 represent the power entering the optical microcavity. The expression for the coupling coefficient between the optical waveguide and the optical microcavity is:

[0046] Where C = |β2-β1|, β1 and β2 are the propagation constants when two adjacent waveguides (including the cases where optical waveguide 20 is adjacent to optical microcavity 30 and optical microcavity 30 is adjacent to each other) exist alone. The propagation constant β depends on the effective refractive index n. i and the wavelength λ of light, that is i = 1, 2, ..., s, as. The difference C reflects the degree of difference in propagation properties between two adjacent waveguides. Δβ = β s -β as ,β s ,β as This is used to calculate the supermode propagation parameters when two waveguides are coupled simultaneously. L is the coupling length.

[0047] As can be seen from the above expression, changing the effective refractive index of any optical waveguide in the coupled waveguide will affect the propagation constant β. i This will in turn affect the values ​​of the difference C and the supermode propagation parameter Δβ, ultimately affecting the coupling coefficient κ. 2 When the coupling coefficient κ 2 When the coupling strength changes, it will also change accordingly. Therefore, the coupling strength can be adjusted by adjusting the effective refractive index of the optical waveguide 20 or the optical microcavity 30.

[0048] In the embodiment shown in FIG1, the orthographic projection of the phase change layer 41 on the substrate 10 overlaps only with the orthographic projection of the optical waveguide 20 on the substrate 10. In the embodiment shown in FIG2, the orthographic projection of the phase change layer 41 on the substrate 10 overlaps simultaneously with the orthographic projections of the two adjacent optical microcavities 30 on the substrate.

[0049] In one embodiment, as shown in Figures 1 and 2, the optical waveguide microcavity further includes a buried layer 11 located between the substrate 10 and the optical waveguide 20 and the optical microcavity 30. The buried layer 11 can play the role of physical support and refractive index matching, which helps to maintain the structural stability of the optical waveguide 20 and the optical microcavity 30 above the substrate 10, and facilitates the formation of a compact and low-loss optical waveguide.

[0050] In one embodiment, as shown in Figures 1 and 2, the optical waveguide microcavity further includes an embedded layer 12. The embedded layer 12 is located on the side of the buried layer 11 away from the substrate 10 and can cover the optical waveguide 20, the optical microcavity 30, and the coupling adjustment structure 40. The embedded layer 12 can provide mechanical protection for other film layers. When the optical waveguide microcavity is subjected to compression or vibration, the embedded layer 12 can absorb part of the external force, reducing the risk of damage to the internal optical components. In one embodiment, the material of the optical waveguide 20 or the optical microcavity 30 includes silicon, silicon nitride, chalcogenide materials, etc.

[0051] In one embodiment, the material of the phase change layer 41 includes optical phase change materials such as germanium telluride, germanium selenide telluride, or germanium antimony selenide telluride. With this configuration, the light absorption coefficient of the phase change layer 41 is low, which can reduce the loss of optical signals during transmission. Furthermore, when the phase change layer 41 uses the above-mentioned materials, the refractive index of the phase change layer 41 has a large range of variation and non-volatile characteristics, which can maintain relative stability after phase change, thereby ensuring the stable operation of the optical waveguide microcavity.

[0052] In one embodiment, the heating layer 42 is made of materials such as titanium nitride and aluminum, which gives the heating layer 42 good thermal conductivity.

[0053] In one embodiment, the coupling adjustment structure 40 further includes a heating electrode 43, which is located on the side of the heating layer 42 away from the substrate 10 and is electrically connected to the heating layer 42 through a through-hole penetrating the buried layer 12. By adjusting electrical parameters such as the voltage applied to the heating electrode 43, the heat generated by the heating layer 42 can be precisely controlled, thereby achieving precise control of the refractive index of the phase change layer 41. By precisely adjusting the refractive index of the phase change layer 41, precise adjustment of the coupling strength between the optical waveguide 20 and the optical microcavity 30, or between two optical microcavities 30, can be achieved. In some embodiments, the material of the heating electrode 43 may include metallic materials such as aluminum or gold.

[0054] In one embodiment, as shown in Figure 3, which is a top view of an optical waveguide microcavity, the optical waveguide microcavity includes an optical waveguide 20 and an optical microcavity 30 located on one side of the optical waveguide 20. The orthographic projection of the phase change layer 41 on the substrate (not shown in Figure 3, but with a projection direction perpendicular to the plane of the paper) overlaps with the orthographic projection of the coupling region of the optical waveguide 20 on the substrate. Heating the heating layer 42 by the heating electrode 43 causes a phase change in the phase change layer 41, altering its refractive index and thus adjusting the coupling strength between the optical waveguide 20 and the optical microcavity 30. In this embodiment, the phase change layer 41 only changes the effective refractive index of the optical waveguide 20, having almost no effect on the refractive index of the optical microcavity 30. Therefore, the light field distribution within the optical microcavity 30 is relatively stable. Thus, while adjusting the coupling strength, the resonant mode position of the optical microcavity 30 can be kept unchanged, which is beneficial for signal transmission stability and facilitates signal modulation.

[0055] In another embodiment, the orthographic projection of the phase change layer 41 onto the substrate overlaps with the orthographic projection of the coupling region of the optical microcavity 30 onto the substrate. In this embodiment, the change in the refractive index of the phase change layer 41 leads to a change in the effective refractive index of the optical microcavity 30, resulting in a change in the optical field distribution mode inside the optical microcavity 30, and consequently, a shift in the position of the resonant mode. This configuration enables the optical waveguide microcavity to perform functions such as selective filtering of optical signals of different frequencies and frequency conversion of light.

[0056] In one embodiment, as shown in FIG4, which is a top view of an optical waveguide microcavity, the optical waveguide microcavity includes an optical waveguide 20, at least two optical microcavities 30 located on the same side of the optical waveguide 20, and the regions enclosed by the orthographic projections of different optical microcavities 30 on the substrate 10 do not overlap. There are multiple coupling adjustment structures 40, one of which has an orthographic projection of its phase change layer 41 on the substrate overlapping with the orthographic projection of the coupling region of the optical waveguide 20 on the substrate. The other coupling adjustment structures 40 also have phase change layers 41 whose orthographic projections overlap with the orthographic projections of the coupling regions of two adjacent optical microcavities 30 on the substrate. The phase change layers 41 overlapping with the coupling regions of the optical waveguide 20 can adjust the coupling strength between the optical waveguide 20 and its adjacent optical microcavities 30, while the other phase change layers 41 overlapping with the coupling regions of adjacent optical microcavities 30 can adjust the coupling strength between the optical microcavities 30.

[0057] In the embodiment shown in Figure 4, the optical waveguide microcavity includes an optical waveguide 20 and two optical microcavities 30, and the two optical microcavities 30 are spaced apart in a direction perpendicular to the extension direction of the optical waveguide 20. In other embodiments, the optical microcavities 30 can also be arranged in other directions, as long as the coupling areas of each optical microcavity 30 do not overlap with those of other optical microcavities 30 or optical waveguide 20.

[0058] In another embodiment, as shown in FIG5, which is a top view of an optical waveguide microcavity, at least two optical microcavities 30 are located on one side of an optical waveguide 20, the diameters of the at least two optical microcavities 30 decrease sequentially, and the at least two optical microcavities 30 are nested. There are multiple coupling adjustment structures 40, one of which has a phase change layer 41 whose orthogonal projection on the substrate overlaps with the orthogonal projection of the coupling region of the optical waveguide 20 on the substrate. The orthogonal projections of the phase change layers 41 of each of the other coupling adjustment structures 40 also overlap with the orthogonal projections of the coupling regions of the two nested optical microcavities 30 on the substrate. The phase change layers 41 overlapping with the coupling regions of the optical waveguide 20 can adjust the coupling strength between the optical waveguide 20 and the adjacent optical microcavities 30, while the remaining phase change layers 41 overlapping with the coupling regions of the nested optical microcavities 30 can adjust the coupling strength between the optical microcavities 30 themselves.

[0059] In one embodiment, as shown in Figure 6, which is a top view of an optical waveguide microcavity, it includes two optical waveguides 20 and an optical microcavity 30 located between the two optical waveguides 20. The orthographic projections of the phase change layers 41 of the two coupling adjustment structures 40 onto the substrate overlap with the orthographic projections of the coupling regions of one optical waveguide 20 onto the substrate. The structure of the two optical waveguides 20 and the optical microcavity 30 between them provides the possibility of bidirectional optical signal transmission. The overlap between the coupling regions of the two coupling adjustment structures 40 and the two optical waveguides 20 allows for independent control of the coupling strength between the two optical waveguides 20 and the optical microcavity 30. Furthermore, optical signals can be coupled from one optical waveguide 20 into the optical microcavity 30 and then coupled to the other optical waveguide 20; this bidirectional signal path increases the flexibility and functionality of the optical system.

[0060] In one embodiment, as shown in Figure 7, which is a top view of an optical waveguide microcavity, it includes two optical waveguides 20 and at least two optical microcavities 30 located between the two optical waveguides 20, and the regions enclosed by the orthographic projections of the different optical microcavities 30 on the substrate 10 do not overlap. There are multiple coupling adjustment structures 40, wherein the orthographic projections of the phase change layers 41 of two coupling adjustment structures 40 on the substrate overlap with the orthographic projections of the coupling regions of the two optical waveguides 20 on the substrate, respectively; and the orthographic projections of the phase change layers 41 of each of the remaining coupling adjustment structures 40 overlap with the orthographic projections of the coupling regions of two adjacent optical microcavities 30 on the substrate. Integrating the two optical waveguides 20 and the multiple spaced-apart optical microcavities 30 together provides abundant optical signal transmission paths and processing units. The two optical waveguides 20 increase the input and output channels for optical signals, and the multiple optical microcavities 30 can serve as independent optical resonators to realize various optical functions, such as filtering, modulation, and optical signal storage.

[0061] In one embodiment, the minimum distance between the optical microcavity 30 and the optical waveguide 20 ranges from 0 μm to 5 μm. Within this distance range, it is beneficial for light to be efficiently coupled from the optical waveguide into the optical microcavity, or from the optical microcavity back to the optical waveguide, thereby achieving high coupling efficiency and avoiding over-coupling due to too small a distance or under-coupling due to too large a distance. In some embodiments, the minimum distance between the optical microcavity 30 and the optical waveguide 20 can be 0.1 μm, 1.5 μm, 3.0 μm, 5 μm, etc.

[0062] In one embodiment, when there are multiple optical microcavities 30, the minimum distance between adjacent optical microcavities 30 ranges from 0 μm to 5 μm. Within this distance range, the light fields of adjacent optical microcavities 30 can influence each other, enabling coupling and energy exchange between them. This avoids over-coupling due to excessively small distances or insufficient coupling due to excessively large distances. In some embodiments, the minimum distance between adjacent optical microcavities 30 can be 0.1 μm, 1.5 μm, 3.0 μm, 5 μm, etc.

[0063] Depending on actual needs, the minimum distance between the optical microcavity 30 and the optical waveguide 20, or the minimum distance between two optical microcavities 30, can be pre-adjusted to allow them to be in different states such as weak coupling and strong coupling. It should be noted that the aforementioned minimum distance refers to the length of the shortest line segment connecting a point on the optical microcavity 30 to the optical waveguide 20 or another point on the optical microcavity 30.

[0064] In one embodiment, the optical microcavity 30 can be a planar microcavity with various irregular shapes but a closed structure, such as a circular microring cavity, a rectangular microring cavity, etc.

[0065] The application of optical waveguide microcavities will be introduced below using Figures 4 and 5 as examples and in conjunction with the schematic diagram of the optical microcavity mode structure. In the schematic diagram of the optical microcavity mode structure shown in Figure 8, the dashed line represents the mode structure of the optical waveguide microcavity before adjustment, and the solid line and shaded area represent the mode structure of the optical waveguide microcavity after adjustment.

[0066] In the embodiment shown in Figure 8, before the coupling strength of the optical waveguide microcavities is adjusted using the coupling adjustment structure 40, each optical microcavity 30 has a resonant mode at position ω0, and at this time there is almost no coupling between the two optical microcavities 30. From the output end of the optical waveguide 20, its transmission spectrum exhibits a single Lorentz line shape within a free spectral range. That is, after the optical signal passes through the optical waveguide microcavity, its frequency distribution characteristics conform to the Lorentz line shape, and the optical signal reaches its peak at the resonant frequency ω0.

[0067] After adjusting the coupling strength of the optical waveguide microcavities using the coupling adjustment structure 40, the coupling strength between the optical microcavities 30 increases, causing the optical fields of the two optical microcavities 30 to interact, thus producing mode splitting. Correspondingly, the transmission spectrum at the output end of the optical waveguide 20 shows two Lorentz lines within a free spectral range, meaning that after adjustment, the optical signal exhibits two different Lorentz lines at the resonant frequency ω. 01 and ω 02 Two peaks appear at this point. By appropriately adjusting the coupling adjustment structure 40, the frequency difference between these two Lorentz curves can be made to be ω. 02 -ω 01 =ω B =2μ (where ω) B (where μ is the Brillouin frequency shift and μ is the correlation parameter), thus achieving the condition for stimulated Brillouin scattering when the frequency is ω. 02 Once the energy of the optical signal reaches a certain threshold, Brillouin laser output can be generated.

[0068] In the embodiment shown in Figure 9, before the coupling strength of the optical waveguide microcavities is adjusted using the coupling adjustment structure 40, coupling already exists between the optical microcavities 30, and two split modes are generated. The transmission spectrum at the output end of the optical waveguide 20 exhibits two Lorentz lines with center frequencies of ω1 and ω2 within a free spectral range, and ω2-ω1=2μ<ω B Therefore, the conditions for stimulated Brillouin scattering are not met. By adjusting the coupling strength of the optical waveguide microcavity using the coupling adjustment structure 40, the frequencies of the two split modes can be adjusted to ω. ′ 1 and ω ′ 2, make ω ′ 2-ω ′ 1=ω B=2μ ′ This satisfies the conditions for stimulated Brillouin scattering, thereby enabling the generation of Brillouin lasers.

[0069] In the embodiment shown in Figure 10, before adjusting the coupling strength of the optical waveguide microcavity using the coupling adjustment structure 40, the mode structure of the optical microcavity 30 includes a mode structure with a frequency of ω1 and a mode structure with a frequency of ω2, and both optical microcavities have a resonant mode at the frequency of ω2. After adjusting the coupling strength of the optical waveguide microcavity using the coupling adjustment structure 40, the mode structure with a frequency of ω2 can be split into modes with frequencies of ω1 and ω2 respectively. 21 and ω 22 The two splitting modes make ω 21 -ω1=ω B Or ω 22 -ω1=ω B This satisfies the frequency difference condition required to generate Brillouin lasers.

[0070] In the embodiment shown in Figure 11, before adjusting the coupling strength of the optical waveguide microcavity using the coupling adjustment structure 40, the mode structure of the optical microcavity 30 includes a frequency of ω. i The optical waveguide microcavities have a resonant mode structure at frequency ω2 and a mode structure at frequency ω2. By adjusting the coupling strength of the optical waveguide microcavities using the coupling adjustment structure 40, the mode structure at frequency ω2 can be split into modes with frequencies ω... P and ω S Two splitting modes. The adjusted mode structure consists of a frequency of ω. i ω P and ω S The pattern composition. By further adjusting the coupling strength, Δ1=ω p -ω i =Δ2=ω s -ω p This satisfies the energy conservation condition for optical parametric oscillations, thereby controlling the occurrence of optical parametric oscillations.

[0071] Figures 8 to 11 only illustrate some application scenarios of optical waveguide microcavities. This application does not specifically limit other applicable scenarios of optical waveguide microcavities.

[0072] This application embodiment also provides an optical waveguide microcavity coupling adjustment device, including: a phase change layer 41 for adjusting the effective refractive index of an optical waveguide and / or optical microcavity disposed below the phase change layer; and a heating layer 42 disposed above the phase change layer for adjusting the temperature of the phase change layer to change the effective refractive index of the phase change layer.

[0073] In one embodiment, the device further includes a heating electrode 43 connected to the heating layer.

[0074] In one embodiment, the device further includes an embedding layer 12 that encapsulates the phase change layer and the heating layer.

[0075] In one embodiment, the material of the phase change layer 41 includes germanium telluride, germanium selenide telluride, or germanium antimony selenide telluride.

[0076] In one embodiment, the heating layer 42 is made of titanium nitride and aluminum.

[0077] It should be noted that the technical solutions or features described in the above embodiments can be combined or supplemented with each other without conflict. The scope of protection of this application is not limited to the precise structures described in the above embodiments and shown in the accompanying drawings; all modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. An optical waveguide microcavity, comprising: Substrate; An optical waveguide is located on one side of the substrate; An optical microcavity is located on the side of the substrate where the optical waveguide is located, and is located on the same layer as the optical waveguide; A coupling adjustment structure includes a phase change layer located on the side of the optical waveguide or the optical microcavity away from the substrate and a heating layer located on the side of the phase change layer away from the substrate. The heating layer is used to adjust the temperature of the phase change layer. The orthographic projection of the phase change layer on the substrate overlaps with the orthographic projection of the coupling region of the optical waveguide and / or the coupling region of the optical microcavity on the substrate.

2. The optical waveguide microcavity according to claim 1, comprising an optical waveguide, an optical microcavity, and a coupling adjustment structure, wherein the optical microcavity is located on one side of the optical waveguide; The orthographic projection of the phase change layer of the coupling adjustment structure on the substrate overlaps with the orthographic projection of the coupling region of the optical waveguide on the substrate, or the orthographic projection of the phase change layer on the substrate overlaps with the orthographic projection of the coupling region of the optical microcavity on the substrate.

3. The optical waveguide microcavity according to claim 1, comprising at least two optical microcavities, one optical waveguide, and multiple coupling adjustment structures, wherein the at least two optical microcavities are located on the same side of the optical waveguide, and the regions enclosed by the orthographic projections of different optical microcavities on the substrate do not overlap; In one of the coupling adjustment structures, the orthographic projection of the phase change layer on the substrate overlaps with the orthographic projection of the coupling region of the optical waveguide on the substrate. In the other two coupling adjustment structures, the orthographic projection of the phase change layer on the substrate overlaps with the orthographic projection of the coupling regions of two adjacent optical microcavities in the at least two optical microcavities on the substrate.

4. The optical waveguide microcavity according to claim 1, wherein, It includes at least two optical microcavities, one optical waveguide, and multiple coupling adjustment structures, wherein the at least two optical microcavities are located on one side of the optical waveguide; the diameters of the at least two optical microcavities decrease sequentially, and the at least two optical microcavities are nested together. In one of the coupling adjustment structures, the orthographic projection of the phase change layer on the substrate overlaps with the orthographic projection of the coupling region of the optical waveguide on the substrate. In the other two coupling adjustment structures, the orthographic projection of the phase change layer on the substrate also overlaps with the orthographic projection of the coupling regions of the at least two nested optical microcavities on the substrate.

5. The optical waveguide microcavity according to claim 1, comprising one optical microcavity, two optical waveguides, and two coupling adjustment structures, wherein the optical microcavity is located between the two optical waveguides; The orthographic projections of the phase change layers of the two coupling adjustment structures onto the substrate overlap with the orthographic projections of the coupling regions of the two optical waveguides onto the substrate.

6. The optical waveguide microcavity according to claim 1, comprising at least two optical microcavities, two optical waveguides, and a plurality of coupling adjustment structures, wherein the at least two optical microcavities are located between the two optical waveguides, and the regions enclosed by the orthographic projections of different optical microcavities on the substrate do not overlap; The orthographic projections of the phase change layers of two of the coupling adjustment structures onto the substrate overlap with the orthographic projections of the coupling regions of the two optical waveguides onto the substrate; the orthographic projections of the phase change layers of the remaining coupling adjustment structures onto the substrate overlap with the orthographic projections of the coupling regions of the two adjacent optical microcavities onto the substrate.

7. The optical waveguide microcavity according to any one of claims 1 to 6, wherein, The minimum distance between the optical microcavity and the optical waveguide ranges from 0 μm to 5 μm.

8. The optical waveguide microcavity according to claim 7, wherein, When there are multiple optical microcavities, the minimum distance between adjacent optical microcavities ranges from 0 μm to 5 μm.

9. The optical waveguide microcavity according to any one of claims 1 to 8, wherein, The coupling adjustment structure further includes a heating electrode, which is electrically connected to the heating layer.

10. The optical waveguide microcavity according to any one of claims 1 to 9, wherein, The phase change layer is made of germanium telluride, germanium selenide telluride, or germanium antimony selenide telluride.

11. An optical waveguide microcavity coupling adjustment device, comprising: A phase change layer is used to adjust the effective refractive index of an optical waveguide and / or optical microcavity disposed beneath the phase change layer. A heating layer is arranged above the phase change layer to regulate the temperature of the phase change layer and change its effective refractive index.

12. The apparatus of claim 11, further comprising a heating electrode connected to the heating layer.

13. The apparatus according to claim 11 or 12 further includes an embedding layer encapsulating the phase change layer and the heating layer.

14. The apparatus according to any one of claims 11 to 13, wherein, The material of the phase change layer includes germanium telluride, germanium selenide telluride, or germanium antimony selenide telluride.

15. The apparatus according to any one of claims 11 to 14, wherein, The heating layer is made of titanium nitride and aluminum.

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