Silicon-based photonic crystal dispersion compensation waveguide

Abstract

The invention discloses a silicon-based photonic crystal dispersion compensation waveguide which solves the problems that an existing dispersion compensation device is large in size and not beneficial to integration, and specifically comprises a flat-plate-shaped photonic crystal waveguide body, an input waveguide and an output waveguide, and the input waveguide and the output waveguide are arranged at the two corresponding ends of the photonic crystal waveguide body. The photonic crystal waveguide body is made of silicon; the photonic crystal waveguide body is provided with a first air hole matrix and a second air hole matrix. A strip-shaped line defect waveguide channel is arranged between the first air hole matrix and the second air hole matrix; the two ends of the line defect waveguide channel correspond to the input waveguide and the output waveguide respectively. The invention designs a waveguide device with a high negative dispersion coefficient in a 1.55 [mu] m communication band to realize a dispersion compensation function by utilizing the dispersion characteristic of the photonic crystal waveguide and aiming at the positive dispersion effect accumulated in long-distance transmission of the traditional single-mode fiber, thereby solving the influence caused by the dispersion effect in optical fiber transmission.

Description

Technical Field

[0001] The present invention relates to a dispersion compensator, and more particularly to a silicon-based photonic crystal dispersion compensation waveguide. Background Art

[0002] The innovation of Internet technology is inseparable from the development of optical fiber communication. The dispersion effect restricts the long-distance communication and high-quality transmission of optical fibers, and the dispersion compensation technology has become one of the key factors to improve the transmission performance of the system.

[0003] Existing dispersion compensation devices (such as dispersion compensation fibers, fiber Bragg gratings, etc.) have long played a key role in optical communication systems, but their physical characteristics are increasingly conflicting with the requirements of modern networks for high bandwidth, high speed, and high density. The dispersion compensation fiber needs to rely on a kilometer-level length to achieve equivalent compensation, resulting in low utilization rate of the rack space; although the fiber Bragg grating has been shortened to a centimeter-level module, it still needs to be fused and packaged as a discrete component, which is not conducive to integration. Summary of the Invention

[0004] In order to solve the technical problems of the large volume and unfavorable integration of existing dispersion compensation devices, the present invention provides a silicon-based photonic crystal dispersion compensation waveguide.

[0005] Inventive Concept of the Present Invention

[0006] The present invention utilizes the dispersion characteristics of photonic crystal waveguides to design a waveguide device with a high negative dispersion coefficient in the 1.55 μm communication band to achieve the function of dispersion compensation for the positive dispersion effect accumulated in the long-distance transmission of traditional single-mode fibers, thereby solving the influence caused by the dispersion effect in optical fiber transmission.

[0007] The silicon optical dispersion compensation waveguide provides a solution to the dispersion problem in optical fiber communication. The silicon optical dispersion compensation waveguide has a negative dispersion coefficient, can effectively compensate the dispersion effect in the optical fiber, and at the same time, the silicon optical dispersion compensation waveguide also has characteristics such as high refractive index, compact structure, and easy integration.

[0008] Photonic crystal waveguides use the characteristics of the periodic refractive index distribution in photonic crystals to control the transmission of light waves. In addition to the characteristics of the above-mentioned silicon optical waveguides, photonic crystals also have diverse structures, good directivity, and nonlinear effects, which are more flexible in designing photonic crystal waveguides with specific functions. The dispersion characteristics of photonic crystal waveguides are an important research direction of photonic crystals. The "anti-crossing" effect in photonic crystal waveguides generates high dispersion and is suitable for making small-size dispersion compensation devices.

[0009] In order to achieve the above object and complete the above inventive concept, the present invention adopts the following technical solutions:

[0010] A silicon-based photonic crystal dispersion compensation waveguide, characterized in that:

[0011] It includes a flat photonic crystal waveguide body, an input waveguide and an output waveguide provided at the corresponding two ends of the photonic crystal waveguide body;

[0012] The material of the photonic crystal waveguide body is silicon;

[0013] A first air hole matrix and a second air hole matrix are provided on the photonic crystal waveguide body;

[0014] A strip-shaped line defect waveguide channel is provided between the first air hole matrix and the second air hole matrix;

[0015] The two ends of the line defect waveguide channel correspond to the input waveguide and the output waveguide respectively.

[0016] Further, the first air hole matrix includes N rows of air holes arranged on one side of the line defect waveguide channel, and adjacent two rows of air holes are horizontally misaligned with each other, so that the center point of any air hole in the Nth row is located on the perpendicular bisector of the line connecting the center points of the corresponding adjacent two air holes in the (N - 1)th row; N≥3 and is a positive integer;

[0017] The second air hole matrix includes M rows of air holes arranged on the other side of the line defect waveguide channel, and adjacent two rows of air holes are horizontally misaligned with each other, so that the center point of any air hole in the Mth row is located on the perpendicular bisector of the line connecting the center points of the corresponding adjacent two air holes in the (M - 1)th row; M≥3 and is a positive integer;

[0018] For both the first air hole matrix and the second air hole matrix, the distance between two air holes in the same row is equal to the distance between adjacent two rows of air holes.

[0019] Further, the width w of the line defect waveguide channel ranges from

[0020] where a is the distance between two adjacent air holes in the same row, and d is the aperture of each air hole.

[0021] Further, the width w of the line defect waveguide channel is

[0022] Further, the aperture d of the air holes ranges from 180nm to 360nm;

[0023] The distance a between two adjacent air holes in the same row ranges from 420nm to 540nm.

[0024] Further, the aperture d of the air holes is 300nm;

[0025] The distance a between two adjacent air holes in the same row is 450 nm.

[0026] Furthermore, the thickness h of the photonic crystal waveguide body ranges from 210 nm to 230 nm.

[0027] Furthermore, the thickness h of the photonic crystal waveguide body is 220 nm.

[0028] Furthermore, the photonic crystal waveguide body, the input waveguide and the output waveguide are fabricated by complementary metal oxide semiconductor process.

[0029] Furthermore, N = M = 5.

[0030] Advantages of the present invention:

[0031] 1. For the silicon-based photonic crystal dispersion compensation waveguide provided by the present invention, a first air hole matrix and a second air hole matrix are arranged on the photonic crystal waveguide body, and a line defect waveguide channel is arranged between the first air hole matrix and the second air hole matrix, so that the waveguide can generate negative dispersion to offset the positive dispersion generated by optical fiber transmission, realizing dispersion compensation.

[0032] 2. For the silicon-based photonic crystal dispersion compensation waveguide provided by the present invention, by utilizing the dispersion characteristics of the photonic crystal waveguide and setting reasonable parameters (a, d, w), the waveguide has a high negative dispersion coefficient in the 1.55 μm communication band, and can provide dispersion compensation for the transmission of optical fiber with extremely small size.

[0033] 3. For the silicon-based photonic crystal dispersion compensation waveguide provided by the present invention, it is fabricated by complementary metal oxide semiconductor process, manufacturing a highly integrated photonic crystal dispersion compensation waveguide, realizing miniaturization and high-performance integration of the device. Description of the drawings

[0034] Figure 1 is a schematic plan view of an embodiment of a silicon-based photonic crystal dispersion compensation waveguide of the present invention;

[0035] Figure 2 is a schematic three-dimensional view of an embodiment of a silicon-based photonic crystal dispersion compensation waveguide of the present invention;

[0036] Figure 3 is a negative dispersion curve diagram in an embodiment of the present invention;

[0037] Figure 4 is Figure 3 the detailed enlarged view of the dispersion curve with the dispersion value of -10 7 ps / (nm·km) magnitude in;

[0038] Figure 5 isFigure 3 The dispersion value in 8 is -10 ps / (nm·km), and the detailed enlarged view of the dispersion curve is shown in the figure.

[0039] Attachment label:

[0040] 1 - Photonic crystal waveguide body, 2 - Input waveguide, 3 - Output waveguide, 4 - First air hole matrix, 5 - Second air hole matrix, 6 - Line defect waveguide channel. Specific implementation mode

[0041] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0042] A silicon-based photonic crystal dispersion compensation waveguide provided by an embodiment of the present invention, as shown in Figure 1 and Figure 2 , includes a flat photonic crystal waveguide body 1, an input waveguide 2 and an output waveguide 3 provided at both corresponding ends of the photonic crystal waveguide body 1;

[0043] The material of the photonic crystal waveguide body 1 is silicon; the thickness h of the photonic crystal waveguide body 1 ranges from 210 nm to 230 nm. In this embodiment, the thickness h of the photonic crystal waveguide body 1 is 220 nm. The photonic crystal waveguide body 1 is provided with a periodically arranged first air hole matrix 4 and a second air hole matrix 5.

[0044] A strip-shaped line defect waveguide channel 6 is provided between the first air hole matrix 4 and the second air hole matrix 5, that is; a row of air holes is removed along the light transmission direction to form the line defect waveguide channel 6; the first air hole matrix 4 includes 5 rows of air holes arranged on one side of the line defect waveguide channel 3, and adjacent rows of air holes are horizontally misaligned with each other, so that the center point of any air hole in any row is located on the perpendicular bisector of the line connecting the center points of the corresponding adjacent two air holes in the adjacent row, forming a two-dimensional hexagonal lattice arrangement array; similarly, the second air hole matrix 5 includes 5 rows of air holes arranged on the other side of the line defect waveguide channel 3, and adjacent rows of air holes are horizontally misaligned with each other, so that the center point of any air hole in any row is located on the perpendicular bisector of the line connecting the center points of the corresponding adjacent two air holes in the adjacent row. For both the first air hole matrix 4 and the second air hole matrix 5, the distance between two air holes in the same row is equal to the distance between adjacent rows of air holes, forming a two-dimensional hexagonal lattice arrangement array.

[0045] Both ends of the line defect waveguide channel 3 correspond to the input waveguide 2 and the output waveguide 3 respectively, and the width w of the line defect waveguide channel 6 ranges from In this embodiment, the width w of the line defect waveguide channel 6 is where a is the distance between two adjacent air holes in the same row (i.e., the lattice constant), and the range of a is 420 nm to 540 nm. In this embodiment, a is 450 nm; d is the aperture of each air hole, and the range of d is 180 nm to 360 nm. In this embodiment, d is 300 nm.

[0046] Based on the unique photonic bandgap effect of photonic crystals, light with a frequency in the forbidden band can only be confined to the central waveguide for transmission. The incident light wave excites two guided modes with different group velocity distributions in this structure. These two modes interact and transform with each other during the transmission process, generating the "anti-crossing" effect, which enables the system to form a significant negative dispersion characteristic in a specific frequency band.

[0047] The core design of this waveguide is based on a triple-parameter regulation mechanism: the lattice constant a, the aperture d of the air holes, and the width w of the line defect waveguide channel 6, to regulate the dispersion characteristics of the guided mode. Specifically, the adjustment of the lattice constant a can achieve the overall translation of the photonic bandgap position, the change of the aperture d can change the bandgap width, and the optimization of the width w affects the effective refractive index distribution of the guided mode. Through the coordinated regulation of the above parameters, the position of the "anti-crossing" region in the energy band diagram of the photonic crystal waveguide is adjusted, and finally a photonic crystal waveguide device with negative dispersion characteristics in the 1.55 μm communication band is constructed.

[0048] As Figures 3 - 5 shown, the analysis of the locally enlarged region of the dispersion curve shows that: when the dispersion value is on the order of -10 7 ps / (nm·km), the corresponding frequency bandwidth is about 220 GHz. This negative dispersion value can compensate for the dispersion of a single-mode optical fiber dozens of kilometers long with a device of centimeter-level length, and at the same time has an ultra-wide operating bandwidth; when the dispersion value reaches -10 8 ps / (nm·km), the available frequency bandwidth still remains about 50 GHz. Under the condition of sacrificing a certain bandwidth, the device size can be further reduced.

[0049] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A silicon-based photonic crystal dispersion compensation waveguide, characterized in that: It includes a flat photonic crystal waveguide body (1), an input waveguide (2) and an output waveguide (3) provided at both corresponding ends of the photonic crystal waveguide body (1); The material of the photonic crystal waveguide body (1) is silicon; A first air hole matrix (4) and a second air hole matrix (5) are provided on the photonic crystal waveguide body (1); A strip-shaped line defect waveguide channel (6) is provided between the first air hole matrix (4) and the second air hole matrix (5); Both ends of the line defect waveguide channel (3) correspond to the input waveguide (2) and the output waveguide (3) respectively.

2. The silicon-based photonic crystal dispersion compensation waveguide according to claim 1, characterized in that: The first air hole matrix (4) includes N rows of air holes arranged on one side of the line defect waveguide channel (3), and adjacent rows of air holes are horizontally offset from each other, so that the center point of any air hole in the Nth row is located on the perpendicular bisector of the line connecting the center points of the corresponding adjacent two air holes in the (N - 1)th row; N≥3 and is a positive integer; The second air hole matrix (5) includes M rows of air holes arranged on the other side of the line defect waveguide channel (3), and adjacent rows of air holes are horizontally offset from each other, so that the center point of any air hole in the Mth row is located on the perpendicular bisector of the line connecting the center points of the corresponding adjacent two air holes in the (M - 1)th row; M≥3 and is a positive integer; For both the first air hole matrix (4) and the second air hole matrix (5), the distance between two air holes in the same row is equal to the distance between adjacent rows of air holes.

3. The silicon-based photonic crystal dispersion compensation waveguide according to claim 2, characterized in that: The width w of the line defect waveguide channel (6) ranges from Wherein, a is the distance between two adjacent air holes in the same row, and d is the aperture of each air hole.

4. The silicon-based photonic crystal dispersion compensation waveguide according to claim 3, characterized in that: The width w of the line defect waveguide channel (6) is 5. The silicon-based photonic crystal dispersion compensation waveguide according to claim 4, characterized in that: The aperture d of the air holes ranges from 180 nm to 360 nm; The distance a between two adjacent air holes in the same row ranges from 420 nm to 540 nm.

6. The silicon-based photonic crystal dispersion compensation waveguide according to claim 5, characterized in that: The aperture d of the air holes is 300 nm; The distance a between two adjacent air holes in the same row is 450 nm.

7. The silicon-based photonic crystal dispersion compensation waveguide according to claim 6, characterized in that: The thickness h of the photonic crystal waveguide body (1) ranges from 210 nm to 230 nm.

8. The silicon-based photonic crystal dispersion compensation waveguide according to claim 7, characterized in that: The thickness h of the photonic crystal waveguide body (1) is 220 nm.

9. The silicon-based photonic crystal dispersion compensation waveguide according to claim 8, characterized in that: The photonic crystal waveguide body (1), the input waveguide (2) and the output waveguide (3) are prepared by complementary metal oxide semiconductor process.

10. The silicon-based photonic crystal dispersion compensation waveguide according to claim 9, characterized in that: It is stated that N = M = 5.

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