Optical modulation module and optical modulator

Abstract

The invention provides an optical modulation module and an optical modulator. The optical modulation module comprises a waveguide layer, and the waveguide layer comprises a flat plate part; the first protruding part and the second protruding part are located on the flat plate part and extend in the first direction, and the distance between the top face of the first protruding part and the bottom face of the flat plate part and the distance between the top face of the second protruding part and the bottom face of the flat plate part are H1; the ridge protruding part is located on the flat plate part, extends in the first direction and is located between the first protruding part and the second protruding part, a first groove is formed between the ridge protruding part and the first protruding part, a second groove is formed between the ridge protruding part and the second protruding part, the distance between the top face of the ridge protruding part and the bottom face of the flat plate part is H2, and H2 is larger than H1.

Description

Technical Field

[0001] The present disclosure relates to the field of optical waveguide technology, and in particular to an optical modulation module and an optical modulator. Background Art

[0002] An optical waveguide is a dielectric device that guides light waves to propagate in it, also known as a dielectric optical waveguide. Rectangular waveguides and ridge waveguides are two common waveguide structures. Rectangular waveguides can better limit and guide light transmission in them, but the interaction effect between the transmitted light and the external field (such as an external electric field) is relatively weak. The interaction effect between the transmitted light and the external field (such as an external electric field) in the ridge waveguide is relatively strong, but the ridge waveguide's ability to limit and guide light transmission in its ridge is relatively weak. Summary of the invention

[0003] The embodiments of the present disclosure provide an optical modulation module and an optical modulator to enhance the limiting and guiding capability of the waveguide layer on light transmission, thereby improving the performance of the device.

[0004] According to one aspect of the present disclosure, there is provided an optical modulation module, comprising a waveguide layer, the waveguide layer comprising: a flat plate portion; a first protruding portion and a second protruding portion, which are located above the flat plate portion and extend along a first direction, and the spacing between the top surfaces of the first protruding portion and the second protruding portion and the bottom surface of the flat plate portion is H1; and a ridge convex portion, which is located above the flat plate portion and extends along the first direction and is located between the first protruding portion and the second protruding portion, a first groove is formed between the ridge convex portion and the first protruding portion, a second groove is formed between the ridge convex portion and the second protruding portion, and the spacing between the top surface of the ridge convex portion and the bottom surface of the flat plate portion is H2, wherein H2>H1.

[0005] In some embodiments, along the first direction, the depths of the first trench and the second trench gradually decrease, and / or the widths of the first trench and the second trench gradually decrease.

[0006] In some embodiments, along the first direction, the depths of the first trench and the second trench gradually increase, and / or the widths of the first trench and the second trench gradually increase.

[0007] In some embodiments, the lengths of the first groove and the second groove along the first direction are equal to or less than the length of the ridge protrusion along the first direction.

[0008] In some embodiments, the optical modulation module further includes: a substrate; an isolation layer located above the substrate, wherein the waveguide layer is formed above the isolation layer; and a covering layer covering the waveguide layer, wherein the material refractive index of the isolation layer and the covering layer is smaller than the material refractive index of the waveguide layer.

[0009] In some embodiments, the cover layer covers the ridge protrusion, the first groove, and the second groove.

[0010] In some embodiments, the covering layer also covers at least a portion of the first protrusion and at least a portion of the second protrusion.

[0011] In some embodiments, the optical modulation module further includes: an electrode layer formed on a surface of the cover layer; or an electrode layer formed on a surface of at least one of the first protrusion and the second protrusion.

[0012] In some embodiments, the optical modulation module includes an electro-optical modulation module or a thermo-optical modulation module.

[0013] According to one aspect of the present disclosure, there is provided an optical modulator, comprising the optical modulation module of the aforementioned aspect.

[0014] According to one or more embodiments of the present disclosure, the first groove and the second groove can prevent the diffusion of the optical mode field in the second direction, so that the light can be propagated more concentratedly in the area where the ridge convex portion is located. Therefore, the design scheme of the embodiment of the present disclosure can improve the limiting and guiding ability of the waveguide layer for light transmission, thereby improving the performance of the device.

[0015] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Further details, features and advantages of the present disclosure are disclosed in the following description of exemplary embodiments in conjunction with the accompanying drawings, in which:

[0017] Figure 1 is a schematic cross-sectional view of an optical modulation module according to some exemplary embodiments of the present disclosure;

[0018] Figure 2 is a schematic cross-sectional view of an optical modulation module according to some exemplary embodiments of the present disclosure;

[0019] Figure 3 is a schematic cross-sectional view of an optical modulation module according to some exemplary embodiments of the present disclosure;

[0020] Figure 4 is a schematic cross-sectional view of an optical modulation module according to some exemplary embodiments of the present disclosure;

[0021] Figure 5A is a schematic diagram of a three-dimensional structure of an optical modulation module according to some exemplary embodiments of the present disclosure;

[0022] Figure 5B is a schematic diagram of a three-dimensional structure of an optical modulation module according to some exemplary embodiments of the present disclosure;

[0023] Figure 5C is a schematic diagram of a three-dimensional structure of an optical modulation module according to some exemplary embodiments of the present disclosure; and

[0024] Figure 5D is a schematic diagram of the three-dimensional structure of an optical modulation module according to some exemplary embodiments of the present disclosure.

[0025] Reference numerals:

[0026] 100-Optical Modulation Module

[0027] 101-Substrate

[0028] 102-Isolation layer

[0029] 103-Waveguide layer

[0030] 104-Overlay

[0031] 105-Electrode layer

[0032] 30- Flat plate

[0033] 31- first protrusion

[0034] 32- Second protrusion

[0035] 33-ridge convex part

[0036] 34-First groove

[0037] 35-Second groove DETAILED DESCRIPTION

[0038] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present disclosure. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0039] A ridge waveguide is a type of optical waveguide that has a series of excellent characteristics such as low main mode cutoff frequency, wide bandwidth and low impedance. A ridge waveguide in the related art includes a planar layer and a ridge convex layer formed in one piece. The interaction effect between the transmitted light in this type of ridge waveguide and the external field (such as an applied electric field) is relatively strong, but the ridge waveguide has a relatively weak ability to limit and guide the transmission of light in its ridge.

[0040] The embodiments of the present disclosure provide an optical modulation module and an optical modulator to enhance the limiting and guiding capability of the waveguide layer on light transmission, thereby improving the performance of the device.

[0041] like Figure 1As shown, the optical modulation module 100 provided in some embodiments of the present disclosure includes a waveguide layer 103, and the waveguide layer 103 includes a flat plate portion 30, a first protruding portion 31, a second protruding portion 32, and a ridge 33. The first protruding portion 31 and the second protruding portion 32 are located on the flat plate portion 30 and extend along a first direction (not shown in the figure, the first direction is perpendicular to the paper surface direction), and the distance between the top surface of the first protruding portion 31 and the second protruding portion 32 and the bottom surface of the flat plate portion 30 is H1. The ridge 33 is located on the flat plate portion 30 and extends along the first direction and is located between the first protruding portion 31 and the second protruding portion 32, a first groove 34 is formed between the ridge 33 and the first protruding portion 31, a second groove 35 is formed between the ridge 33 and the second protruding portion 32, and the distance between the top surface of the ridge 33 and the bottom surface of the flat plate portion 30 is H2, wherein H2>H1.

[0042] The first direction may be the direction of light transmission or the reverse direction of light transmission. In the optical modulation module 100 of the embodiment of the present disclosure, the ridge 33 of the waveguide layer 103 is separated from the first protrusion 31 by the first groove 34, and separated from the second protrusion 32 by the second groove 35, and the spacing between the top surface of the ridge 33 and the bottom surface of the flat plate 30 (that is, the maximum material thickness of the region where the ridge 33 is set in the waveguide layer 103) is greater than the spacing between the top surface of the first protrusion 31 and the second protrusion 32 and the bottom surface of the flat plate 30 (that is, the maximum material thickness of the region where the first protrusion 31 and the second protrusion 32 are set in the waveguide layer 103). In this way, the first groove 34 and the second groove 35 can prevent the diffusion of the optical mode field in the second direction, so that the light can be propagated more concentratedly in the region where the ridge 33 is located. Therefore, the design scheme of the embodiment of the present disclosure can improve the limiting and guiding ability of the waveguide layer 103 on light transmission, thereby improving the performance of the device.

[0043] In the embodiment of the present disclosure, the specific product type of the optical modulation module 100 is not limited, for example, it can be an electro-optic modulation module or a thermo-optic modulation module. The electro-optic modulation module performs phase modulation on the transmitted light based on the electro-optic effect of the waveguide material, and the modulation speed is relatively fast. The thermo-optic modulation module performs phase modulation on the transmitted light based on the thermo-optic effect of the waveguide material, and its modulation speed is relatively slow, but it has the advantages of a large phase modulation range and high modulation efficiency.

[0044] like Figure 2As shown, in some embodiments of the present disclosure, in addition to the waveguide layer 103, the optical modulation module 100 further includes a substrate 101, an isolation layer 102, and a cover layer 104, wherein the substrate 101, the isolation layer 102, the waveguide layer 103, and the cover layer 104 are sequentially arranged, the waveguide layer 103 is formed on the isolation layer 102, and the material refractive indexes of the isolation layer 102 and the cover layer 104 are both smaller than the material refractive index of the waveguide layer 103. The isolation layer 102 and the cover layer 104 have a lower refractive index than the waveguide layer 103, and light can be mainly confined to be transmitted in the waveguide layer 103, thereby giving play to the above-mentioned advantages of the ridge waveguide.

[0045] Reference Figure 3 As shown, in some embodiments, the cover layer 104 covers the ridge 33, the first groove 34 and the second groove 35, and also covers at least a portion of the first protrusion 31 and at least a portion of the second protrusion 32. In this way, the electrode layer 105 can be arranged on the cover layer 104, and the design style and arrangement height of the electrodes in the electrode layer 105 can be flexibly adjusted by adjusting the coverage area and thickness of the cover layer 104, so as to match the electrical transmission speed and the optical transmission speed as much as possible. Figure 3 As shown, according to some embodiments of the present disclosure, the optical modulation module 100 further includes an electrode layer 105 formed on the surface of the cover layer 104 .

[0046] In some other embodiments of the present disclosure, the cover layer 104 may also only cover the ridge 33, the first groove 34 and the second groove 35, and the electrode layer 105 may be directly formed on the surface of the waveguide layer 103. Figure 4 As shown, according to some embodiments of the present disclosure, the optical modulation module 100 further includes an electrode layer 105 formed on a surface of at least one of the first protruding portion 31 and the second protruding portion 32 .

[0047] like Figure 5A As shown, in some embodiments of the present disclosure, a first groove 34 is formed between the ridge 33 and the first protrusion 31, and a second groove 35 is formed between the ridge 33 and the second protrusion 32, wherein the width W of the first groove 34 and the second groove 35 gradually decreases along the first direction.

[0048] like Figure 5B As shown, in some embodiments of the present disclosure, a first groove 34 is formed between the ridge 33 and the first protrusion 31, and a second groove 35 is formed between the ridge 33 and the second protrusion 32, wherein the width W of the first groove 34 and the second groove 35 gradually increases along the first direction.

[0049] like Figure 5CAs shown, in some embodiments of the present disclosure, a first groove 34 is formed between the ridge 33 and the first protrusion 31, and a second groove 35 is formed between the ridge 33 and the second protrusion 32, wherein along the first direction, the depth H of the first groove 34 and the second groove 35 gradually decreases, and the width also gradually decreases until the grooves disappear.

[0050] like Figure 5D As shown, in some embodiments of the present disclosure, a first groove 34 is formed between the ridge 33 and the first protrusion 31, and a second groove 35 is formed between the ridge 33 and the second protrusion 32, wherein along the first direction, the depth and width of the first groove 34 and the second groove 35 gradually increase from zero.

[0051] In some embodiments of the present disclosure, Figure 5A As shown, the length of the first groove 34 and the second groove 35 along the first direction may be less than the length of the ridge 33 along the first direction. In other embodiments of the present disclosure, the length of the first groove and the second groove along the first direction may also be equal to the length of the ridge along the first direction, that is, the first groove and the second groove penetrate the waveguide layer along the first direction.

[0052] In the above embodiment, the variation trend of the depth and / or width of the first groove 34 and the second groove 35 can be determined according to the light transmission direction and the specific type of the photonic device optically coupled to the optical modulation module 100. The depth and / or width of the first groove 34 and the second groove 35 are designed to be gradually changed, which can moderately prevent the diffusion of the optical mode field in the second direction, so that the optical modulation module 100 can achieve moderate and smooth modulation of the mode spot, which is beneficial to reduce the light transmission loss.

[0053] The embodiment of the present disclosure also provides an optical modulator, including the optical modulation module 100 according to any of the above embodiments. The optical modulator is, for example, a thermo-optic modulator or an electro-optic modulator. The electro-optic modulator can be, for example, a Mach-Zehnder modulator, and in addition to the above optical modulation module 100, can also include a light splitting element, a light combining element, etc.

[0054] Based on the above design of the optical modulation module 100 and the beneficial effects obtained, the device performance of the optical modulator is improved accordingly, the optical transmission loss is small, and the modulation efficiency is higher.

[0055] It should be understood that in this specification, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships or dimensions that are based on the orientations or positional relationships or dimensions shown in the accompanying drawings, and these terms are used only for the convenience of description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present disclosure.

[0056] In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", "third" may explicitly or implicitly include one or more of the feature. In the description of the present disclosure, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0057] In the present disclosure, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0058] In the present disclosure, unless otherwise expressly specified and limited, a first feature being “above” or “below” a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being “above”, “above”, and “above” a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0059] This specification provides many different embodiments or examples that can be used to implement the present disclosure. It should be understood that these different embodiments or examples are purely exemplary and are not intended to limit the scope of protection of the present disclosure in any way. Those skilled in the art can conceive of various changes or replacements based on the disclosure of the present specification, which should all be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection defined by the attached claims.

Claims

1. An optical modulation module, comprising a waveguide layer, wherein the waveguide layer comprises: Flat plate department; A first protruding portion and a second protruding portion are located on the flat plate portion and extend along a first direction, and a distance between a top surface of the first protruding portion and a top surface of the second protruding portion and a bottom surface of the flat plate portion is H1; as well as A ridge portion is located above the flat plate portion and extends along the first direction and is located between the first protruding portion and the second protruding portion, a first groove is formed between the ridge portion and the first protruding portion, a second groove is formed between the ridge portion and the second protruding portion, and the distance between the top surface of the ridge portion and the bottom surface of the flat plate portion is H2, wherein H2>H1.

2. The optical modulation module according to claim 1, wherein: Along a first direction, the depths of the first groove and the second groove gradually decrease, and / or the widths of the first groove and the second groove gradually decrease.

3. The optical modulation module according to claim 1, wherein: Along a first direction, the depths of the first groove and the second groove gradually increase, and / or the widths of the first groove and the second groove gradually increase.

4. The optical modulation module according to claim 1, wherein: The lengths of the first groove and the second groove along the first direction are equal to or smaller than the length of the ridge convex portion along the first direction.

5. The optical modulation module according to claim 1, further comprising: substrate; an isolation layer located on the substrate, wherein the waveguide layer is formed on the isolation layer; and A covering layer covering the waveguide layer, wherein the material refractive index of the isolation layer and the covering layer is smaller than the material refractive index of the waveguide layer.

6. The optical modulation module according to claim 5, wherein: The cover layer covers the ridge convex portion, the first groove, and the second groove.

7. The optical modulation module according to claim 6, wherein: The covering layer also covers at least a portion of the first protrusion and at least a portion of the second protrusion.

8. The optical modulation module according to any one of claims 1 to 7, further comprising: an electrode layer formed on a surface of the covering layer; or An electrode layer is formed on a surface of at least one of the first protrusion and the second protrusion.

9. The optical modulation module according to any one of claims 1 to 7, wherein: The optical modulation module includes an electro-optical modulation module or a thermo-optical modulation module. 10 . An optical modulator, comprising the optical modulation module according to claim 1 .

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