Array waveguide grating based on artificial standard field dense waveguide superlattice

Abstract

The invention provides an array waveguide grating based on an artificial standard field dense waveguide superlattice, which comprises an input region, an array waveguide region and an output region which are sequentially connected, and is characterized in that the input region comprises an input waveguide, a first free transmission region and a first parabolic waveguide which are sequentially connected along a waveguide transmission direction; the output area comprises a second parabolic waveguide, a second free transmission area and an output waveguide which are sequentially connected in the waveguide transmission direction. The array waveguide area comprises a first sine bending waveguide, a first Euler bending waveguide area, a straight waveguide, a second Euler bending waveguide area and a second sine bending waveguide which are sequentially connected in the waveguide transmission direction. According to the invention, the array waveguide region is mainly formed by sequentially and alternately connecting the sine bending waveguide, the straight waveguide and the two Euler bending waveguide regions, and the sine bending waveguide with alternating width is designed in combination with the waveguide superlattice of an artificial standard field, and has the advantages of low loss, low crosstalk, compact structure and the like.

Description

Technical Field

[0001] The present invention relates to the field of optical communication and co-packaged photon integrated interconnection, and in particular to an array waveguide grating based on an artificial gauge field dense waveguide superlattice. Background Art

[0002] Due to the increasing popularity and rapid development of cloud processing, big data and mobile Internet. Dense wavelength division multiplexing technology is considered to be one of the effective technologies to solve the massive communication needs, requiring higher speed, larger bandwidth and higher quality network data exchange methods. In the 1990s, wavelength division multiplexing (WDM) technology based on optical bands came into being. This is a technology that effectively expands communication capacity and increases communication rate. In the wavelength division multiplexing transmission network, the wavelength division multiplexer / demultiplexer is a crucial core component, and the arrayed waveguide grating is one of the most excellent wavelength division multiplexers / demultiplexers, and occupies an important position in many dense wavelength division multiplexing systems and modules.

[0003] Arrayed waveguide gratings are important components in wavelength division multiplexing systems. They have the advantages of high integration and low loss. Therefore, they are widely used in optical interconnection in data centers, which can improve the transmission capacity in optical communications. In recent years, domestic and foreign research teams have been committed to developing high-performance arrayed waveguide gratings based on different materials and different structures. For example, the research involves various types of arrayed waveguide gratings such as silica buried waveguides, polymer waveguides, indium phosphide ridge waveguides, and silicon photonic waveguides. These efforts aim to improve the performance of AWGs to meet the growing communication needs.

[0004] The existing Chinese patent with publication number CN115144964A discloses a silicon-based arrayed waveguide grating based on Euler-bent wide waveguide. It includes an input waveguide, a first free transmission area, a first transition area, a first adiabatic tapered waveguide, an arrayed waveguide area, a second adiabatic tapered waveguide, a second transition area, a second free transmission area and an output waveguide connected in sequence along the waveguide transmission direction. The arrayed waveguide area is mainly composed of three multimode wide waveguide areas and two Euler-bent wide waveguide areas connected alternately in sequence, and the curved part of the arrayed waveguide area is composed of the Euler-bent wide waveguide area, and both ends of the arrayed waveguide area are respectively connected to the input area and the output area through the multimode wide waveguide area; the design of double-layer etching and adiabatic tapered waveguide is adopted in the first transition area and the second transition area, and the arrayed waveguide area uses multimode wide waveguide and Euler-bent wide waveguide.

[0005] However, the arrayed waveguide gratings in the prior art still have limited effectiveness. Therefore, there is a need to provide an arrayed waveguide grating based on an artificial gauge field dense waveguide superlattice, which has excellent performance such as lower loss, lower crosstalk and more compactness, reduces the device size without affecting the overall loss, helps to further reduce manufacturing costs, and can also improve the integration of the device. Summary of the invention

[0006] In view of the defects in the prior art, the object of the present invention is to provide an array waveguide grating based on an artificial gauge field dense waveguide superlattice.

[0007] An arrayed waveguide grating based on an artificial gauge field dense waveguide superlattice provided by the present invention comprises: an input area, an arrayed waveguide area and an output area connected in sequence, the input area comprises: an input waveguide, a first free transmission area and a first parabolic waveguide connected in sequence along a waveguide transmission direction, the output area comprises: a second parabolic waveguide, a second free transmission area and an output waveguide connected in sequence along a waveguide transmission direction, the arrayed waveguide area comprises: a first sinusoidal curved waveguide, a first Euler curved waveguide area, a straight waveguide, a second Euler curved waveguide area and a second sinusoidal curved waveguide connected in sequence along a waveguide transmission direction, the first parabolic waveguide is connected to the first sinusoidal curved waveguide, and the second sinusoidal curved waveguide is connected to the second parabolic waveguide;

[0008] The arrayed waveguide region is a symmetrical structure with respect to the straight waveguide, and the input region and the output region have the same structure and are symmetrically arranged at two ends of the arrayed waveguide region.

[0009] Preferably, the first sinusoidal curved waveguide and the second sinusoidal curved waveguide comprise an array of sinusoidal curved waveguides with alternating width and narrowness.

[0010] Preferably, the first Euler curved waveguide region and the second Euler curved waveguide region are respectively arranged at curved parts of the array waveguide region.

[0011] Preferably, the first Euler curved waveguide region and the second Euler curved waveguide region both include a plurality of Euler curved waveguides arranged in an array and spaced apart from each other, and the bending radii of the Euler curved waveguides are the same, and the curvature variation satisfies the Archimedean spiral equation.

[0012] Preferably, both the first free transmission area and the second free transmission area include a Rowland circle structure, and the corresponding input ends and output ends of the two are located on the same arc.

[0013] Preferably, the input waveguide comprises a single waveguide, and the output waveguide comprises a plurality of waveguides with uniform spacing.

[0014] Preferably, the input waveguide and the output waveguide each include a plurality of waveguides with uniform spacing, and the waveguide spacings of the two are the same.

[0015] Preferably, the first parabolic waveguide and the second parabolic waveguide each include a plurality of waveguides with uniform intervals, and the waveguide intervals of the two are the same.

[0016] Preferably, the first parabolic waveguide and the second parabolic waveguide control the input light to be coupled into the arrayed waveguide region in the form of a fundamental mode.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention is composed of an arrayed waveguide region, which is mainly composed of a wide and narrow alternating sinusoidal curved waveguide, a straight waveguide and two Euler curved waveguide regions alternately connected in sequence. The wide and narrow alternating sinusoidal curved waveguide is designed in combination with a waveguide superlattice of an artificial gauge field to achieve broadband low crosstalk at a relatively close spacing. The arrayed waveguide region, with the help of a dense waveguide superlattice combined with an artificial gauge field and Euler bending with a gradual curvature, helps to achieve low-loss and high-density fundamental mode transmission; it has the advantages of low loss, low crosstalk, compact structure, etc., and helps to improve the optical communication capacity per unit area.

[0019] 2. The present invention comprises an Euler curved waveguide region through a curved portion of an array waveguide region. Since the curvature of the Euler curved wide waveguide changes gradually and the curvature of the Euler curved wide waveguide changes with the bending angle to satisfy the Archimedean spiral equation, mode mismatch of light during transmission is avoided and high-order modes may not be excited.

[0020] 3. The present invention controls the input light to couple into the array waveguide region in the form of fundamental mode through the first parabolic waveguide and the second parabolic waveguide, so as to reduce the degree of mode mismatch and transmission loss, and at the same time filter out a small amount of high-order modes, reduce crosstalk, ensure high coupling efficiency and reduce crosstalk between channels. The input light always maintains the fundamental mode in the adiabatic tapered waveguide. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0022] Figure 1 The present invention mainly embodies the structural schematic diagram of an arrayed waveguide grating based on an artificial gauge field dense waveguide superlattice;

[0023] Figure 2 It is a schematic diagram of the structure of the parabolic waveguide in the input and output regions of the present invention;

[0024] Figure 3This is a schematic diagram of the structure of the Euler bending waveguide in the array waveguide mainly embodied in the present invention;

[0025] Figure 4 This is a schematic diagram of the structure of a dense waveguide superlattice based on an artificial gauge field, which is mainly embodied in the present invention;

[0026] Figure 5 The present invention mainly embodies the simulation schematic diagram of crosstalk between dense waveguides in an array waveguide.

[0027] As shown in the figure:

[0028] Input waveguide 1 First free transmission region 2 First parabolic waveguide 3

[0029] First sinusoidal waveguide 4 First Euler waveguide region 5 Straight waveguide 6

[0030] Second Euler curved waveguide region 7 Second sinusoidal curved waveguide 8 Second parabolic waveguide 9

[0031] Second free transmission region 10 Output waveguide 11 DETAILED DESCRIPTION

[0032] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0033] like Figure 1 As shown, an arrayed waveguide grating based on an artificial gauge field dense waveguide superlattice provided by the present invention includes: an input area, an arrayed waveguide area and an output area connected in sequence, the input area includes: an input waveguide 1, a first free transmission area 2 and a first parabolic waveguide 3 connected in sequence along the waveguide transmission direction, the output area includes: a second parabolic waveguide 9, a second free transmission area 10 and an output waveguide 11 connected in sequence along the waveguide transmission direction, the arrayed waveguide area includes: a first sinusoidal curved waveguide 4, a first Euler curved waveguide area 5, a straight waveguide 6, a second Euler curved waveguide area 7 and a second sinusoidal curved waveguide 8 connected in sequence along the waveguide transmission direction, the first parabolic waveguide 3 is connected to the first sinusoidal curved waveguide 4, and the second sinusoidal curved waveguide 8 is connected to the second parabolic waveguide 9; the arrayed waveguide area is a symmetrical structure about the straight waveguide 6, and the input area and the output area have the same structure and are symmetrically arranged at both ends of the arrayed waveguide area.

[0034] The present application proposes a compact arrayed waveguide grating based on a dense waveguide superlattice combined with an artificial gauge field, which can reduce device size and cost and improve on-chip integration. The arrayed waveguide region is mainly composed of a wide and narrow alternating sinusoidal curved waveguide, a straight waveguide and two Euler curved waveguide regions connected alternately in sequence. The design principle of the wide and narrow alternating sinusoidal curved waveguide is to combine the waveguide superlattice with an artificial gauge field to achieve broadband low crosstalk at a relatively close spacing. The present application has the advantages of low loss, low crosstalk, and compact structure.

[0035] The first sinusoidal curved waveguide 4 and the second sinusoidal curved waveguide 8 comprise a sinusoidal curved waveguide array with alternating width and narrowness, and the design principle thereof is to combine a waveguide superlattice with an artificial gauge field to achieve broadband low crosstalk at a relatively close spacing.

[0036] The first Euler curved waveguide region 5 and the second Euler curved waveguide region 7 are respectively arranged at the curved part of the arrayed waveguide region, that is, the curved part of the arrayed waveguide region is composed of the Euler curved waveguide region.

[0037] The first Euler curved waveguide area 5 and the second Euler curved waveguide area 7 both include a plurality of Euler curved waveguides arranged in an array and spaced apart from each other, and the bending radii of the Euler curved waveguides are the same, and the curvature variation satisfies the Archimedean spiral equation, thereby ensuring mode matching of light during transmission and avoiding the excitation of high-order modes.

[0038] The straight waveguide 6 is mainly composed of a front and rear array of multiple straight waveguides, and the width of the straight waveguide is related to the effective refractive index of the dense waveguide superlattice based on the artificial gauge field. The introduction of sinusoidal bending will increase the effective refractive index of the waveguide. The corresponding straight waveguide width needs to be appropriately widened to make its effective refractive index consistent with the connected sinusoidal curved waveguide, and the spacing between adjacent straight waveguides can be calculated based on the length difference of adjacent array waveguides.

[0039] Specifically, according to Bloch theory, by optimizing the design parameters of the sinusoidal waveguide array with alternating width and narrowness, it is possible to control the low crosstalk between adjacent channels under broadband operation at a relatively close spacing, thereby making the device structure more compact. In the Euler curved waveguide region, since the curvature of the Euler curved wide waveguide changes gradually, and the curvature of the Euler curved wide waveguide changes with the bending angle to satisfy the Archimedean spiral equation, the mode mismatch of light during transmission is avoided, and high-order modes can be avoided from being excited.

[0040] The first free transmission area 2 and the second free transmission area 10 both include the same Rowland circle structure, and the corresponding input and output ends of the two are located on the same arc. More specifically, the output end of the first free transmission area 2 and the input end of the second free transmission area 10 are both on the same arc.

[0041] The input waveguide 1 includes a single waveguide, and the output waveguide 11 includes a plurality of waveguides with uniform spacing. In other specific embodiments, the input waveguide 1 and the output waveguide 11 may both include a plurality of waveguides with uniform spacing, and the waveguide spacings of the two may be the same.

[0042] The first parabolic waveguide 3 and the second parabolic waveguide 9 both include a plurality of waveguides with uniform intervals, and the intervals between the waveguides are the same.

[0043] By reasonably selecting the widths of the first parabolic waveguide 3 and the second parabolic waveguide 9, the input light is controlled to be coupled into the array waveguide region in the form of a fundamental mode, so as to reduce the degree of mode mismatch and transmission loss, and at the same time filter out a small amount of existing high-order modes, reduce crosstalk, ensure high coupling efficiency and reduce crosstalk between channels, and the input light always maintains the fundamental mode form in the adiabatic tapered waveguide.

[0044] The length difference between adjacent waveguides in the arrayed waveguide grating of the present application is a certain value, so that there is a constant optical path difference.

[0045] Specifically, a wide spectrum input light is input from an input waveguide 1, and the input light field intensity is Gaussian distributed. The input light is diffracted when passing through the first free transmission zone 2 of the input area, and the diffracted input light is coupled into the array waveguide area for transmission. Since there is a constant length difference between two adjacent waveguides in the array waveguide area, lights of different wavelengths will have different phase differences, so that the input light undergoes multi-beam interference in the second free transmission zone 10 of the output area. Since lights of different wavelengths are imaged at different positions of the Rowland circle, the input light after multi-beam interference is output from multiple output waveguides 2 through the second free transmission zone 10 to obtain lights with different wavelengths, thereby realizing the spectroscopic function.

[0046] On the contrary, light with different specific wavelengths is input from the corresponding waveguides of the multiple output waveguides 11. Due to the reversibility of the optical path, light with different specific wavelengths will be output from one input waveguide 1, thereby realizing the beam combining function of light with different specific wavelengths.

[0047] like Figure 2 As described above, by optimizing W1, W2, L1 and the shape order m of the parabolic waveguide, their relationship satisfies the following equation: w(x) = α(Lx) m +w2; w(0)=w1; w(L)=w2; α=(w1-w2) / L m Through optimization, it can be obtained that on the 220nm SOI platform, the parabolic curve series m = 2, the input end width W1 = 2.5um, the output end width W2 = 2.5um, and the waveguide length L1 = 10um.

[0048] like Figure 3As shown, the Euler bend of the Euler bend waveguide in the present application is 90 degrees, and the middle point of the Euler bend wide waveguide is the minimum radius R min , and the minimum radius R min The size is 20um, and the edge part has the maximum radius R max , and the maximum radius R max The size is 2000um, the radius of the middle part is gradually changing, and the effective radius R of the middle part is eff The size is 37um.

[0049] like Figure 4 As shown, the dense waveguide superlattice combined with the artificial gauge field in the present application is a sinusoidal curved waveguide array with alternating width, a modulation period P of 10um, an amplitude A of 0.53um, and a waveguide width of 0.5um and 0.54um.

[0050] like Figure 5 As shown, in the present application, by introducing a dense waveguide superlattice combined with an artificial gauge field, the array waveguide maintains a crosstalk below -40 dB at 1450 nm to 1650 nm at a spacing of 1 micron, which can reduce the size of the device and improve the integration of the device.

[0051] The present application utilizes a wide and narrow alternating sinusoidal curved waveguide to replace the array waveguide region, thereby achieving low crosstalk between channels while reducing the device size without affecting the overall loss.

[0052] This application has excellent properties such as low loss, low crosstalk and compactness, and is expected to increase the optical communication capacity per unit area. The array waveguide region successfully achieves low-loss and high-density fundamental mode transmission by means of dense waveguide superlattice combined with artificial gauge field and curvature gradient Euler bending.

[0053] This application introduces a dense arrangement of sinusoidal curved waveguides with alternating widths and narrownesses as the array waveguides of the array waveguide grating, which can effectively reduce the size of the on-chip array waveguide grating while maintaining low crosstalk. This design not only helps to further reduce manufacturing costs, but also improves the integration of devices. In addition, this design method is also applicable to other material platforms such as silicon nitride, lithium niobate, polymer waveguides, etc., providing flexibility and scalability for different applications.

[0054] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the 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 a limitation on the present application.

[0055] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. An arrayed waveguide grating based on an artificial gauge field dense waveguide superlattice, characterized in that: The invention comprises: an input area, an arrayed waveguide area and an output area which are connected in sequence; the input area comprises: an input waveguide (1), a first free transmission area (2) and a first parabolic waveguide (3) which are connected in sequence along the waveguide transmission direction; the output area comprises: a second parabolic waveguide (9), a second free transmission area (10) and an output waveguide (11) which are connected in sequence along the waveguide transmission direction; the arrayed waveguide area comprises: a first sinusoidal curved waveguide (4), a first Euler curved waveguide area (5), a straight waveguide (6), a second Euler curved waveguide area (7) and a second sinusoidal curved waveguide (8) which are connected in sequence along the waveguide transmission direction; the first parabolic waveguide (3) is connected to the first sinusoidal curved waveguide (4); and the second sinusoidal curved waveguide (8) is connected to the second parabolic waveguide (9); The arrayed waveguide region is a symmetrical structure with respect to the straight waveguide (6); the input region and the output region have the same structure and are symmetrically arranged at two ends of the arrayed waveguide region.

2. The arrayed waveguide grating based on artificial gauge field dense waveguide superlattice according to claim 1, characterized in that: The first sinusoidal curved waveguide (4) and the second sinusoidal curved waveguide (8) comprise a sinusoidal curved waveguide array with alternating width and narrowness.

3. The arrayed waveguide grating based on artificial gauge field dense waveguide superlattice according to claim 1, characterized in that: The first Euler curved waveguide region (5) and the second Euler curved waveguide region (7) are respectively arranged at the curved part of the array waveguide region.

4. The arrayed waveguide grating based on artificial gauge field dense waveguide superlattice according to claim 1, characterized in that: The first Euler curved waveguide area (5) and the second Euler curved waveguide area (7) both comprise a plurality of Euler curved waveguides arranged in an array and spaced apart from each other, and the bending radii of the Euler curved waveguides are all the same, and the curvature variation satisfies the Archimedean spiral equation.

5. The arrayed waveguide grating based on artificial gauge field dense waveguide superlattice according to claim 1, characterized in that: The first free transmission area (2) and the second free transmission area (10) both comprise a Rowland circle structure, and the corresponding input ends and output ends of the two are located on the same arc.

6. The arrayed waveguide grating based on artificial gauge field dense waveguide superlattice according to claim 1, characterized in that: The input waveguide (1) comprises a single waveguide, and the output waveguide (11) comprises a plurality of waveguides with uniform spacing.

7. The arrayed waveguide grating based on artificial gauge field dense waveguide superlattice according to claim 1, characterized in that: The input waveguide (1) and the output waveguide (11) both include a plurality of waveguides with uniform spacing, and the waveguide spacings of the two are the same.

8. The arrayed waveguide grating based on artificial gauge field dense waveguide superlattice according to claim 1, characterized in that: The first parabolic waveguide (3) and the second parabolic waveguide (9) both include a plurality of waveguides with uniform spacing, and the waveguide spacings of the two are the same.

9. The arrayed waveguide grating based on artificial gauge field dense waveguide superlattice according to claim 1, characterized in that: The first parabolic waveguide (3) and the second parabolic waveguide (9) control the input light to be coupled into the array waveguide region in the form of a fundamental mode.

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