Asymmetric wave combiner and decoder chip based on reverse design

Abstract

The present invention discloses an asymmetric wave combining and demultiplexing chip based on reverse design, which belongs to the technical field of optical elements, systems or instruments. The chip includes a first-level asymmetric wave combining and demultiplexing unit and a second-level symmetric wave combining and demultiplexing unit; the proposed asymmetric wave combining and demultiplexing chip is constructed by silicon-based photonic integration technology, and includes a substrate, a lower cladding, a core layer and an upper cladding stacked in sequence from bottom to top; the functional areas inside the first-level asymmetric wave combining and demultiplexing unit and the second-level symmetric wave combining and demultiplexing unit are designed based on a reverse design algorithm, and are composed of sub-micron or nanometer-level sub-units. The asymmetric wave combining and demultiplexing chip of the present invention can cover the entire wavelength band in the optical communication system and realize non-uniform wavelength division of energy in the entire wavelength band; the proposed asymmetric wave combining and demultiplexing chip has an ultra-compact structure, adjustable wavelength interval, non-uniform transmittance of each wavelength, small channel interval crosstalk, stable performance, simple design, and can be mass-produced based on mature semiconductor processes.

Description

Technical Field

[0001] The invention discloses an asymmetric wave combining and decomposing chip based on reverse design, relates to optical communication and integrated optoelectronic device technology, and belongs to the technical field of optical elements, systems or instruments. Background Art

[0002] With the rapid increase of high-definition data streams on the Internet, the demand for communication capacity from user terminals has shown a great growth trend. In the past few decades, optical communication systems have made important contributions to the improvement of communication capacity. The invention and widespread commercial use of wavelength division multiplexing (WDM) technology have met people's demand for data traffic. The bands used by traditional WDM systems are concentrated in the C band, which is difficult to meet future communication needs. In order to further increase system capacity, optical communication systems must expand the available bands to the O+E+S+C+L bands to realize a full-band wavelength division multiplexing technology solution.

[0003] In order to build a full-band wavelength division multiplexing system, it is necessary to study the corresponding full-band combiner and demultiplexer chips. Traditional combiner and demultiplexer chips are generally limited to the C band and are difficult to cover the O+E+S+L band. Due to the existence of the "water peak" inside the optical fiber, the optical fiber transmission loss is uneven and nonlinear in the O+E+S+C+L band, especially in the E band where there is a high transmission loss "water peak". In order to realize the combiner and demultiplexer function with non-uniform output waveguide transmittance, it is necessary to propose a full-band asymmetric combiner and demultiplexer technology to finely adjust the output characteristics of each wavelength to achieve full-band non-uniform output.

[0004] At present, most of the asymmetric wave combining and demultiplexing technologies are based on thin-film devices, which are large in size, poor in stability, and poor in wavelength expansion. In order to further improve the performance of asymmetric wave combining and demultiplexing, asymmetric wave combining and demultiplexing chips based on photonic integration technology have become a new choice. Silicon-based photonic integrated chips have high optoelectronic performance, compact size, low cost, and are compatible with complementary metal oxide semiconductor (CMOS) manufacturing processes. However, the dispersion problem of silicon-based photonic integration technology limits the realization of high-performance asymmetric wave combining and demultiplexing chips. Traditional silicon-based photonic integration technology based on forward design is restricted by its structural principles and cannot realize ultra-small large-scale optoelectronic devices.

[0005] In recent years, photonic integrated devices based on reverse design have been proposed one after another, which can realize wavelength division multiplexing devices, ultra-compact resonant cavities, and mode multiplexing devices with higher integration. However, the number of channels of the current reverse-designed photonic integrated devices is generally small, and it is impossible to realize the multi-channel asymmetric wave combining and demultiplexing function. Therefore, it is necessary to propose a new type of asymmetric wave combining and demultiplexing chip based on reverse design to solve the above problems. Summary of the invention

[0006] The purpose of the present invention is to address the deficiencies of the above-mentioned background technology and provide an asymmetric combiner and demultiplexer chip based on reverse design. Through reverse design and silicon-based photonic integration technology, an asymmetric combiner and demultiplexer chip with ultra-high integration and stable performance is realized, and the purpose of the invention is to achieve full-band transmittance or non-uniform output of wavelength intervals, improve signal transmission density, increase optical fiber utilization, extend transmission distance, and solve the technical problems of large size, poor stability, and poor wavelength expansion of thin-film asymmetric combiner and demultiplexer chips.

[0007] The present invention adopts the following technical solutions to achieve the above-mentioned invention object:

[0008] An asymmetric wave-combining and de-multiplexing chip based on reverse design includes: a first-stage asymmetric wave-combining and de-multiplexing unit and at least N second-stage symmetric wave-combining and de-multiplexing units; the first asymmetric wave-combining and de-multiplexing unit has an input waveguide and at least N+M output waveguides, a group of optical signals with different wavelengths are input from the input waveguide of the first-stage asymmetric wave-combining and de-multiplexing unit, the N output waveguides of the first-stage asymmetric wave-combining and de-multiplexing unit respectively output a group of optical signals with different wavelengths but the same transmittance to a second symmetric wave-combining and de-multiplexing unit, the M output waveguides of the first-stage asymmetric wave-combining and de-multiplexing unit respectively output one optical signal among M optical signals with different transmittances, and N and M are both integers greater than or equal to 1.

[0009] Optionally, one of the M output waveguides of the first-stage asymmetric wave combiner and demultiplexer is connected to the N+1th second-stage symmetric wave combiner and demultiplexer, and at least two of the M optical signals with different transmittances are transmitted to the input waveguide of the N+1th second-stage symmetric wave combiner and demultiplexer via one of the M output waveguides of the first-stage asymmetric wave combiner and demultiplexer, and the output waveguide of the N+1th second-stage symmetric wave combiner and demultiplexer outputs at least two of the M optical signals with different transmittances by wavelength division.

[0010] Optionally, at least one of the N output waveguides of the first-level asymmetric combiner and demultiplexer is connected to the input waveguide of the third-level symmetric combiner and demultiplexer, and part of the optical signals in a group of optical signals with different wavelengths but the same transmittance output by one of the N output waveguides of the first-level asymmetric combiner and demultiplexer is transmitted to a third-level symmetric combiner and demultiplexer, and the third-level symmetric combiner and demultiplexer outputs part of the optical signals in a group of optical signals with different wavelengths but the same transmittance by wavelength division.

[0011] The functional areas inside the first-stage asymmetric wave-combining unit, the second-stage symmetric wave-combining unit and the third-stage symmetric wave-combining unit are designed based on a reverse design algorithm and are composed of sub-micron or nanometer-scale sub-units.

[0012] The first-level asymmetric wave-combining and decomposing unit functional area, the second-level symmetric wave-combining and decomposing unit functional area, and the third-level symmetric wave-combining and decomposing unit functional area are optimized and designed using inverse design algorithms, such as direct binary search (DBS). The three functional areas are rectangular and multiple sub-wavelength units are introduced inside. The material of each sub-wavelength unit can be silicon dioxide or silicon, or silicon dioxide or doped silicon dioxide, corresponding to the silicon-on-insulator (SOI) platform and the silicon-on-silicon (SoS) platform, respectively. First, the sub-wavelength unit material type is randomly set; then its FOM is given as follows:

[0013] FOM=FOM(O1)+…+FOM(O m+p )+…+FOM(O m+p+q+1 )+FOM(O m+p+q+2 )+…FOM(O m+p+q+r )+FOM(O m+p+q+s+1 )+…+FOM(O m+p+q+s+w ),

[0014] in:

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024] The FOM function is a MAX function established with the goal of minimizing the difference between the actual output optical loss of each output waveguide of the combiner and decompressor unit and the target output optical loss. The actual output optical loss of the output waveguide of the combiner and decompressor unit is the ratio of the transmittance of the output waveguide to the input waveguide for the optical signal of the same wavelength.

[0025] Next, each sub-wavelength unit is traversed, the size changes of FOM are calculated and compared, and the material types with larger FOM are selectively retained; all sub-wavelength units are traversed through multiple iterations to give the optimal structure of the functional area.

[0026] As a further improvement of the present invention, the first-stage asymmetric wave combining and decomposing unit can realize multi-wavelength asymmetric and different loss wave splitting. The second-stage symmetric wave combining and decomposing unit and the third-stage symmetric wave combining and decomposing unit are both symmetric wave combining and decomposing units, which can realize multi-wavelength uniform and equal loss wave splitting.

[0027] As a further improvement of the present invention, the sizes of the first-level asymmetric wave combining and decomposing unit functional area, the second-level symmetric wave combining and decomposing unit functional area and the third-level symmetric wave combining and decomposing unit functional area are all in the order of square micrometers or square millimeters.

[0028] As a further improvement of the present invention, the asymmetric wave combining and decomposing chip can realize multi-wavelength wave splitting within the O+E+S+C+L band, the number of wavelengths can be 6, 7, 8, 9, 10, 12, 16, 18, 32, 48, 55, 64, 128, etc., and the wavelength output characteristics are adjustable; the internal working mode of the chip can be a transverse electric mode or a transverse magnetic mode; the mode order can be a fundamental mode or a high-order mode.

[0029] As a further improvement of the present invention, the first-stage asymmetric wave combining and decomposing unit is connected to the second-stage symmetric wave combining and decomposing unit through an S-shaped curved waveguide, and multiple wavelengths can pass through the interior of the S-shaped curved waveguide with low loss.

[0030] As a further improvement of the present invention, the input waveguides of the first-stage asymmetric wave combiner and demultiplexer, the second-stage symmetric wave combiner and demultiplexer, and the third-stage symmetric wave combiner and demultiplexer are all arranged at the center, and the output waveguides are evenly arranged.

[0031] As a further improvement of the present invention, the asymmetric wave combining and decomposing chip can be based on any one of the platforms of silicon on insulator, silicon dioxide on silicon, InP, GaAs, polymer, lithium niobate, diamond, and sulfur-based material platforms, and the asymmetric wave combining and decomposing chip can be mass-produced using semiconductor technology.

[0032] As a further improvement of the present invention, the asymmetric wave-splitting chip can optimize the structure of each wave-splitting unit functional area based on DBS algorithm, semi-constrained algorithm, particle swarm algorithm, level set method, density topology optimization, basic gradient algorithm, gradient descent algorithm and genetic algorithm, and deep learning inverse design algorithm, so as to achieve a design with higher efficiency, smaller size and higher device performance.

[0033] The present invention adopts the above technical solution and has the following beneficial effects:

[0034] (1) The asymmetric wavelength combination and decomposition chip of the present invention can cover the entire wavelength band (O+E+S+C+L band) in the optical communication system, realize non-balanced wavelength division of the entire wavelength band energy, and can make the chip structure ultra-compact based on reverse design, with adjustable output wavelength interval, non-uniform transmittance of each wavelength, small channel interval crosstalk, stable performance and simple design.

[0035] (2) The asymmetric wave combining and demultiplexing chip of the present invention has strong scalability and can realize arbitrary selection of two wavelengths to multiple wavelengths. The simple evaluation function can realize the efficient optimization design of ultra-compact chips. The cascade structure of asymmetric and symmetric wave combining and demultiplexing units can realize the function of multi-channel and multi-wavelength asymmetric wave combining and demultiplexing.

[0036] (3) The asymmetric wave combining and decomposing chip of the present invention uses silicon material to prepare the wave combining and decomposing unit functional area, and can be mass-produced in batches based on mature semiconductor processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the topological structure of the asymmetric wave combining and decomposing chip of the present invention.

[0038] Figure 2 It is a schematic diagram of the specific structure of the asymmetric wave combining and decomposing chip in Example 1 of the present invention.

[0039] Figure 3 It is a schematic diagram of the structure of the first-stage asymmetric wave combining and decomposing unit in Example 1 of the present invention.

[0040] Figure 4 It is a structural diagram of the second-stage symmetrical wave combining and decomposing unit 002 in Embodiment 1 of the present invention.

[0041] Figure 5 It is a structural diagram of the second-stage symmetrical wave combining and decomposing unit 006 in Embodiment 1 of the present invention.

[0042] Figure 6 This is the output spectrum diagram of the asymmetric wave combining and decomposing chip in Example 1 of the present invention.

[0043] Figure 7 It is a schematic diagram of the specific structure of the asymmetric wave combining and decomposing chip in Example 2 of the present invention.

[0044] Figure 8 This is the output spectrum diagram of the asymmetric wave combining and decomposing chip in Example 2 of the present invention.

[0045] Explanation of the numbers in the figure: 001 is the first-level asymmetric wave combining and decomposing unit, 002, 004, 005, 006, and 007 are the second-level symmetric wave combining and decomposing units, 003 and 008 are the third-level symmetric wave combining and decomposing units, 101 is the input waveguide of the first-level asymmetric wave combining and decomposing unit, 102 is the functional area of ​​the first-level asymmetric wave combining and decomposing unit, 103-106 are the output waveguides of the first-level asymmetric wave combining and decomposing unit, 201 is the input waveguide of the second-level symmetric wave combining and decomposing unit 002, 202 is the functional area of ​​the second-level symmetric wave combining and decomposing unit 202, 203-206 are the output waveguides of the second-level symmetric wave combining and decomposing unit 002, 601 is the input waveguide of the second-level symmetric wave combining and decomposing unit 006, 602 is the functional area of ​​the second-level symmetric wave combining and decomposing unit 006, and 603-608 are the output waveguides of the second-level symmetric wave combining and decomposing unit 006. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0047] According to the output waveguide pair λ1 to λ n The transmittance of the n wavelength optical signal is converted from λ1 to λ by the asymmetric combiner and demultiplexer. n A total of n wavelength optical signals are divided into several groups of optical signals with uniform transmittance and optical signals with a large difference from the uniform transmittance. The several groups of optical signals with uniform transmittance are respectively output through a symmetrical combiner / demultiplexer unit, and the optical signals with a large difference from the uniform transmittance are respectively output from the output waveguide of the asymmetrical combiner / demultiplexer unit or output by wavelength division after passing through the symmetrical combiner / demultiplexer unit. The general topology of the asymmetrical combiner / demultiplexer chip of the present invention is as follows: Figure 1 As shown, it includes: a first-level asymmetric wave combining and decomposing unit 001, a second-level symmetric wave combining and decomposing unit 002, a second-level symmetric wave combining and decomposing unit 004, a second-level symmetric wave combining and decomposing unit 005, a second-level symmetric wave combining and decomposing unit 006, a second-level symmetric wave combining and decomposing unit 007, a third-level symmetric wave combining and decomposing unit 003, and a third-level symmetric wave combining and decomposing unit 008. λ1 to λ n A total of n wavelengths of optical signals are input from the input waveguide of the first-stage asymmetric combiner and demultiplexer 001, and the input waveguides of the second-stage symmetric combiner and demultiplexer 002, the second-stage symmetric combiner and demultiplexer 004, the second-stage symmetric combiner and demultiplexer 006, and the second-stage symmetric combiner and demultiplexer 007 are respectively connected to one output waveguide of the first-stage asymmetric combiner and demultiplexer 001, and the second-stage symmetric combiner and demultiplexer 002, the second-stage symmetric combiner and demultiplexer 004, the second-stage symmetric combiner and demultiplexer 006, and the second-stage symmetric combiner and demultiplexer 007 respectively output a group of optical signals with different wavelengths but the same transmittance, for example, wavelengths of λ1, λ2, ...λ mA group of optical signals is transmitted through the first output waveguide O1 of the first-stage asymmetric combiner and demultiplexer 001 to the second-stage symmetric combiner and demultiplexer 002, with a wavelength of λ m+p , m+p+1 , …λ m+p+q A group of optical signals are transmitted through the m+pth output waveguide O of the first-stage asymmetric combiner / decomposer 001. m+p Transmitted to the second-stage symmetrical wave combining and decomposing unit 004, the wavelength is λ m+p+q+s+1 , m+p+q+s+2 , …λ m+p+q+s+t A group of optical signals are output to the m+p+q+s+1th output waveguide O of the first-stage asymmetric combiner / decomposer 001. m+p+q+s+1 Transmitted to the second-stage symmetrical wave combining and decomposing unit 006, the wavelength is λ m+p+q+s+t+w , m+p+q+s+t+w+1 , …λ n-v , n-v+1 , …λ n A group of optical signals are output to the m+p+q+s+wth output waveguide O of the first-stage asymmetric combiner / decomposer 001. m+p+q+s+w The remaining wavelengths of optical signals are respectively output through the other output waveguides of the first-stage asymmetric combiner and decompressor 001 or sent to the second-stage symmetric combiner and decompressor 005 for wavelength division processing and then output respectively. For example, the wavelength is λ m+p+q+1 The optical signal is output to the m+p+q+1th output waveguide O of the first-stage asymmetric combiner / decomposer 001. m+p+q+1 Direct output, wavelength λ m+p+q+2 The optical signal is output to the m+p+q+2th output waveguide O of the first-stage asymmetric combiner / decomposer 001. m+p+q+2 Direct output, wavelength is λ m+p+q+r , m+p+q+r+1 , …λ m+p+q+s A group of optical signals are output to the m+p+q+rth output waveguide O of the first-stage asymmetric combiner / decomposer 001. m+p+q+r The second-level symmetrical wave combining and decomposing unit 002 and the second-level symmetrical wave combining and decomposing unit 007 are respectively connected to the third-level wave combining and decomposing unit 003 and the third-level wave combining and decomposing unit 008, with wavelengths of λ1, λ2, ...λ c A group of optical signals are output by the third-level combiner / demultiplexer 003, with a wavelength of λ n-v , n-v+1 , …λ n A group of optical signals are wavelength-divided and outputted by the third-stage combiner / demultiplexer 008. Optionally, a fourth-stage symmetrical combiner / demultiplexer is connected after the third-stage symmetrical combiner / demultiplexer, and a multi-channel multi-wavelength asymmetrical combiner / demultiplexer can be realized by cascading an asymmetrical combiner / demultiplexer and a symmetrical combiner / demultiplexer.

[0048] In determining Figure 1 After the asymmetric combiner and demultiplexer chip general topology is shown, it is necessary to optimize the design of the first-level asymmetric combiner and demultiplexer unit functional area, the second-level symmetric combiner and demultiplexer unit functional area, and the third-level symmetric combiner and demultiplexer unit functional area through reverse design algorithms such as direct binary search (DBS). Each functional area is a rectangular structure and multiple sub-wavelength units are introduced inside. The material of each sub-wavelength unit can be silicon dioxide or silicon, or silicon dioxide or doped silicon dioxide, corresponding to the silicon-on-insulator (SOI) platform and the silicon-on-silicon (SoS) platform respectively.

[0049] First, the material type of each sub-wavelength unit in the first-level asymmetric wave-combining unit is randomly set; then, the evaluation function FOM of the first-level asymmetric wave-combining unit is given; then, with the goal of maximizing FOM, the sub-wavelength units of the first-level asymmetric wave-combining unit are traversed, and the material type of each sub-wavelength unit when FOM is maximized is selected. The design of the functional area of ​​the second-level symmetric wave-combining unit and the third-level symmetric wave-combining unit is the same as the design idea of ​​the first-level asymmetric wave-combining unit, and the present invention will not be repeated.

[0050] The evaluation function FOM of the first-level asymmetric wave combining unit is: FOM = FOM (O1) + ... + FOM (O m+p )+…+FOM(O m+p+q+1 )+FOM(O m+p+q+2 )+…FOM(O m+p+q+r )+FOM(O m+p+q+s+1 )+…+FOM(O m+p+q+s+w ),

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062] Among them, FOM (O1) is the first output waveguide O1 of the first-stage asymmetric wave combiner and decomposer for wavelengths λ1, λ2, ...λ m The transmittance of a group of optical signals The evaluation function of The input waveguide pair of the first-stage asymmetric wave combiner and decomposer has wavelengths of λ1, λ2, ...λ m The transmittance of a group of optical signals, is the target output optical loss of the first output waveguide O1 of the first-stage asymmetric combiner / decomposer; FOM(O m+p ) is the m+pth output waveguide O of the first-stage asymmetric wave combiner and decomposer m+p For wavelength λ m+p , m+p+1 , …λ m+p+q The transmittance of a group of optical signals The evaluation function of The wavelength of the input waveguide pair of the first-stage asymmetric wave combiner and decomposer is λ m+p , m+p+1 , …λ m+p+q The transmittance of a group of optical signals, The m+pth output waveguide O of the first-stage asymmetric wave combiner and decomposer m+p Target output optical loss; FOM(O m+p+q+1 ) is the m+p+q+1th output waveguide O of the first-stage asymmetric wave combining and decomposing unit m+p+q+1 For wavelength λ m+p+q+1 The transmittance of the optical signal The evaluation function of The wavelength of the input waveguide pair of the first-stage asymmetric wave combiner and decomposer is λ m+p+q+1 The transmittance of the optical signal, The m+p+q+1th output waveguide O of the first-stage asymmetric wave combiner and decomposer m+p+q+1 Target output optical loss; FOM(O m+p+q+2 ) is the m+p+q+2th output waveguide O of the first-stage asymmetric wave combining and decomposing unit m+p+q+2 For wavelength λ m+p+q+2 The transmittance of the optical signal The evaluation function of The wavelength of the input waveguide pair of the first-stage asymmetric wave combiner is λ m+p+q+2 The transmittance of the optical signal, The m+p+q+2th output waveguide O of the first-stage asymmetric wave combiner and decomposerm+p+q+2 Target output optical loss; FOM(O m+p+q+r ) is the m+p+q+rth output waveguide O of the first-stage asymmetric wave combining and decomposing unit m+p+q+r For wavelength λ m+p+q+r , m+p+q+r+1 , …λ m+p+q+s The transmittance of a group of optical signals The evaluation function of The wavelength of the input waveguide pair of the first-stage asymmetric wave combiner and decomposer is λ m+p+q+r , m+p+q+r+1 , …λ m+p+q+s The transmittance of a group of optical signals, The m+p+q+rth output waveguide O of the first-stage asymmetric wave combiner and decomposer m+p+q+r Target output optical loss; FOM(O m+p+q+s+1 ) is the m+p+q+s+1th output waveguide O of the first-stage asymmetric wave combining and decomposing unit m+p+q+s+1 For wavelength λ m+p+q+s+1 , m+p+q+s+2 , …λ m+p+q+s+t The transmittance of a group of optical signals The evaluation function of The wavelength of the input waveguide pair of the first-stage asymmetric wave combiner and decomposer is λ m+p+q+s+1 , m+p+q+s+2 , …λ m+p+q+s+t The transmittance of a group of optical signals, The m+p+q+s+1th output waveguide O of the first-stage asymmetric wave combiner and decomposer m+p+q+s+1 Target output optical loss; FOM(O m+p+q+s+w ) is the m+p+q+s+wth output waveguide O of the first-stage asymmetric wave combining and decomposing unit m+p+q+s+w For wavelength λ m+p+q+s+t+w , m+p+q+s+t+w+1 , …λ n-v , n-v+1 , …λ n The transmittance of a group of optical signals The evaluation function of The wavelength of the input waveguide pair of the first-stage asymmetric wave combiner and decomposer is λ m+p+q+s+t+w , m+p+q+s+t+w+1 , …λ n-v , n-v+1 , …λ n The transmittance of a group of optical signals, The m+p+q+s+wth output waveguide O of the first-stage asymmetric wave combiner and decomposer m+p+q+s+wBy setting the values ​​of c, m, p, q, r, s, t, w, and n, which are positive integers that increase in sequence, non-uniform adjustment of the output wavelength power and interval can be achieved.

[0063] Specific embodiment 1: Asymmetric wave combination and decomposition chip to achieve non-uniform output of 12 wavelength signal transmittance in the O+E+S+C+L band

[0064] like Figure 2 , Figure 3 , Figure 4 as well as Figure 5 As shown, this embodiment provides an asymmetric wave combining and decomposing chip, that is, realizing the O+E+S+C+L band from λ1 to λ 12 A total of 12 wavelengths with non-uniform transmittance output, λ1 to λ 12 They correspond to λ1=1271nm, λ2=1291nm, λ3=1311nm, λ4=1331nm, λ5=1351nm, λ6=1371nm, λ7=1471nm, λ8=1491nm, λ9=1511nm, λ 10 =1531nm,λ 11 =1551nm,λ 12 =1571nm; where λ1 to λ5 are located in the O band, λ6 is located in the E band, λ7 to λ9 are located in the S band, 10 To 11 Located in C band, λ 12 Located in the L band. The asymmetric combiner and decoder chip is a passive device with ultra-small size and ultra-high stability.

[0065] The wavelengths are λ1, λ2, ...λ 12 The output spectrum of a set of optical signals is as follows Figure 6 As shown by Figure 6 It can be seen that the output loss of the optical signals with wavelengths of λ1, λ2, λ3, and λ4 is 2.5dB, and the output loss of λ7, λ8, λ9, and λ 10 , 11 , 12 The output loss of the optical signals of the six wavelengths is 2dB, and the output loss of the optical signals of wavelengths λ5 and λ6 are 0.9dB and 0.6dB respectively. The first-stage asymmetric combiner and decompressor is used to combine the optical signals of wavelengths λ1, λ2, ...λ 12 A group of optical signal waves are divided into four groups of signals and then output. For optical signals with wavelengths of λ1, λ2, λ3, and λ4, and wavelengths of λ7, λ8, λ9, and λ 10 , 11 , 12The optical signal with wavelength λ5 and λ6 is directly output through an output waveguide of the first-stage asymmetric combiner / decomposer unit, realizing wavelengths λ1, λ2, ...λ 12 The specific structure of an asymmetric wave combining and decomposing chip with a group of optical signal transmittance non-uniform output is as follows Figure 2 shown.

[0066] like Figure 2 As shown, the wavelengths achieved are λ1, λ2, ...λ 12 A group of asymmetric wave combining and decomposing chips with non-uniform output of optical signal transmittance includes: a first-level asymmetric wave combining and decomposing unit 001, a second-level symmetric wave combining and decomposing unit 002, and a second-level symmetric wave combining and decomposing unit 006. The first-level asymmetric wave combining and decomposing unit 001 is connected to the second-level symmetric wave combining and decomposing unit 002 through an S-type waveguide, and the first-level asymmetric wave combining and decomposing unit 001 is connected to the second-level symmetric wave combining and decomposing unit 006 through an S-type waveguide; the proposed asymmetric wave combining and decomposing chip is constructed by silicon-based photonic integration technology, including a silicon substrate, a silicon dioxide lower cladding, a silicon core layer and a silicon dioxide upper cladding stacked in sequence from bottom to top, and the first-level asymmetric wave combining and decomposing unit and the second-level symmetric wave combining and decomposing unit are located in the core layer.

[0067] like Figure 3 As shown, the first-stage asymmetric combiner and demultiplexer input waveguide 101 is located at the left center of the first-stage asymmetric combiner and demultiplexer functional area 102, and the first-stage asymmetric combiner and demultiplexer output waveguides 103, 104, 105, and 106 are evenly arranged on the right side of the first-stage asymmetric combiner and demultiplexer functional area 102. The input waveguide 101 of the first-stage asymmetric combiner and demultiplexer inputs λ1 to λ 12 The first-stage asymmetric combiner and demultiplexer output waveguide 103 outputs optical signals with a total of 12 wavelengths, and the first-stage asymmetric combiner and demultiplexer output waveguide 104 outputs an optical signal with a wavelength of λ5. The first-stage asymmetric combiner and demultiplexer output waveguide 105 outputs an optical signal with a wavelength of λ6. The first-stage asymmetric combiner and demultiplexer output waveguide 106 outputs an optical signal with a wavelength of λ7 to λ8. 12There are a total of 6 wavelengths of optical signals, and the output optical losses of the output waveguides 103, 104, 105 and 106 of the first-stage asymmetric combiner and demultiplexer are different. The functional area 102 of the first-stage asymmetric combiner and demultiplexer is optimized based on the DBS algorithm, and the FOM is defined as the minimum MAX function of the difference between the actual output optical loss and the target output optical loss of the output waveguides 103, 104, 105 and 106 of the first-stage asymmetric combiner and demultiplexer; the material of each sub-wavelength unit in the functional area 102 of the first-stage asymmetric combiner and demultiplexer is silicon dioxide or silicon, corresponding to the silicon-on-insulator platform. First, the type of sub-wavelength unit material is randomly set; then, each sub-wavelength unit is traversed, the size change of FOM is calculated and compared, and the material type with a larger FOM is selectively retained; after traversing all sub-wavelength units through multiple iterations and determining the material type of each sub-wavelength unit, the optimal structure of the functional area 102 of the first-stage asymmetric combiner and demultiplexer is given, with a size of 2×4μm. 2 .

[0068] like Figure 4 As shown, the second-level symmetrical wave combining and decomposing unit input waveguide 201 is located at the left center of the second-level symmetrical wave combining and decomposing unit functional area 202, and the second-level symmetrical wave combining and decomposing unit output waveguides 203, 204, 205, and 206 are evenly arranged on the right side of the second-level symmetrical wave combining and decomposing unit functional area 202. The second-level symmetrical wave combining and decomposing unit input waveguide 201 inputs optical signals of 4 wavelengths from λ1 to λ4, the second-level symmetrical wave combining and decomposing unit output waveguide 203 outputs an optical signal with a wavelength of λ1, the second-level symmetrical wave combining and decomposing unit output waveguide 204 outputs an optical signal with a wavelength of λ2, the second-level symmetrical wave combining and decomposing unit output waveguide 205 outputs an optical signal with a wavelength of λ3, and the second-level symmetrical wave combining and decomposing unit output waveguide 206 outputs an optical signal with a wavelength of λ4. The output optical losses of the second-level symmetrical wave combining and decomposing unit output waveguides 203, 204, 205, and 206 are the same. The second-level symmetrical wave-combining and decomposing unit functional area 202 is designed based on the DBS algorithm optimization, and FOM is defined as the MAX function with the smallest difference between the actual output optical loss and the target output optical loss of the output waveguides 203, 204, 205 and 206 of the second-level symmetrical wave-combining and decomposing unit; the material of each sub-wavelength unit in the second-level symmetrical wave-combining and decomposing unit functional area 202 is silicon dioxide or silicon, corresponding to the silicon-on-insulator platform. First, the sub-wavelength unit material type is randomly set; then each sub-wavelength unit is traversed, the size change of FOM is calculated and compared, and the material type with a larger FOM is selectively retained; through multiple iterations of traversing all sub-wavelength units, the material type of each sub-wavelength unit is determined, and the optimal structure of the functional area of ​​the second-level symmetrical wave-combining and decomposing unit 002 is given, with a size of 1.5×4μm 2 .

[0069] like Figure 5As shown, the second-stage symmetrical wave combining and decomposing unit input waveguide 601 is located at the left center of the functional area 602 of the second-stage symmetrical wave combining and decomposing unit 006, and the output waveguides 603, 604, 605, 606, 607, and 608 of the second-stage symmetrical wave combining and decomposing unit 006 are evenly arranged on the right side of the functional area 602 of the second-stage symmetrical wave combining and decomposing unit 006. The input waveguide 601 of the second-stage symmetrical wave combining and decomposing unit 006 inputs λ7 to λ8. 12 There are 6 wavelengths of optical signals in total. The output waveguide 603 of the second-stage symmetrical wave combining and decomposing unit 006 outputs an optical signal with a wavelength of λ7. The output waveguide 604 of the second-stage symmetrical wave combining and decomposing unit outputs an optical signal with a wavelength of λ8. The output waveguide 605 of the second-stage symmetrical wave combining and decomposing unit 006 outputs an optical signal with a wavelength of λ9. The output waveguide 606 of the second-stage symmetrical wave combining and decomposing unit 006 outputs an optical signal with a wavelength of λ 10 The output wavelength of the output waveguide 607 of the second-stage symmetrical wave combining and decomposing unit 006 is λ 11 The output wavelength of the output waveguide 608 of the second-stage symmetrical wave combining and decomposing unit 006 is λ 12 The optical signal of the second-level symmetrical combiner and decomposition unit 006 has the same output optical loss of the output waveguides 603 to 608. The functional area 602 of the second-level symmetrical combiner and decomposition unit 006 is optimized based on the DBS algorithm; FOM is defined as the MAX function with the smallest difference between the actual output optical loss and the target output optical loss of the output waveguides 603 to 608; the material of each sub-wavelength unit in the functional area 602 of the second-level symmetrical combiner and decomposition unit 006 is silicon dioxide or silicon, corresponding to the silicon-on-insulator platform. First, the type of sub-wavelength unit material is randomly set; then, each sub-wavelength unit is traversed, the size change of FOM is calculated and compared, and the material type with a larger FOM is selectively retained; all sub-wavelength units are iterated through multiple times to determine the material type of each sub-wavelength unit, and the optimal structure of the functional area of ​​the second-level symmetrical combiner and decomposition unit 006 is given, with a size of 2×5μm 2 .

[0070] Specific embodiment 2: Asymmetric wave combination and decomposition chip to achieve non-uniform output of six wavelength signals in the O+E band

[0071] like Figure 7 , Figure 8 As shown, as an extension of the present invention, this embodiment provides an asymmetric wave combining and decomposing chip based on reverse design to realize the transmittance asymmetric wave combining and decomposing function of 6 wavelengths from λ1 to λ6, and the wavelengths corresponding to λ1 to λ6 are 1271nm, 1291nm, 1311nm, 1331nm, 1351nm and 1371nm respectively.

[0072] The output spectrum of a group of optical signals with wavelengths of λ1, λ2, ...λ6 is as follows: Figure 8 As shown by Figure 8 It can be seen that the output loss of the four wavelengths from λ1 to λ4 is 1.5dB, and the output losses of the wavelengths of λ5 and λ6 are 0.6dB and 0.3dB respectively. A first-stage asymmetric combiner / demultiplexer is used to divide a group of optical signals with wavelengths of λ1, λ2, ...λ6 into three groups of signals and then output them. For optical signals with wavelengths of λ1, λ2, λ3, and λ4, a second-stage symmetric combiner / demultiplexer is used to perform wavelength division processing and then output them. For optical signals with wavelengths of λ5 and λ6, they are directly output through an output waveguide of the first-stage asymmetric combiner / demultiplexer, respectively, to achieve a group of optical signals with wavelengths of λ1, λ2, ...λ6. The specific structure of the asymmetric combiner / demultiplexer chip with non-uniform transmittance output is as follows: Figure 7 shown.

[0073] An asymmetric wave combiner and demultiplexer chip is provided to realize a group of optical signal transmittances with wavelengths of λ1, λ2, ...λ6 with non-uniform output. The functional areas of the first-stage asymmetric wave combiner and demultiplexer unit 001 and the second-stage symmetric wave combiner and demultiplexer unit 002 are optimized by the same reverse design as in Example 1. The optimized size of the first-stage asymmetric wave combiner and demultiplexer unit 001 is 2×3 μm. 2 The optimized size of the second-stage symmetrical wave combining and decomposing unit 002 is 1.5×4μm 2 .

[0074] In summary, the present invention provides an asymmetric wave-combining and wave-decomposing chip based on reverse design, which can realize non-uniform power in the whole band and non-equidistant output of wavelength intervals. The chip structure has ultra-small size, stable performance, and low crosstalk; the wavelength and channel scalability are strong, and multiple wavelength multiplexing can be realized. The preparation materials of the asymmetric wave-combining and wave-decomposing chip can be expanded to other materials (including but not limited to silicon on insulator, silicon dioxide on silicon, InP, GaAs, polymers, lithium niobate, diamond, sulfur series and other materials). The present invention shows the wave-decomposing function of 12 wavelengths, and the wave-combining function can also be realized based on this structure. The reverse design algorithm shown in the present invention is only the DBS algorithm, which can be expanded to the reverse design algorithm based on the semi-constrained algorithm, particle swarm algorithm, level set method, density topology optimization, basic gradient algorithm, gradient descent algorithm and genetic algorithm, deep learning, etc. according to the present invention. The present invention only shows the chip structure at the 12 and 6 wavelength levels, which can be expanded from 12 wavelengths to more wavelength levels according to the present invention to achieve richer asymmetric wave-combining and wave-decomposing effects. Meanwhile, the present invention has a simple design, a mature manufacturing process, and is compatible with the CMOS manufacturing process, and has a wide application prospect in the optical communication wavelength division multiplexing system.

[0075] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. Asymmetric wave combining and decomposing chip based on reverse design, characterized in that: include: The first-stage asymmetric wave combiner / decomposer unit has an input waveguide connected to a group of optical signals with different wavelengths, its N output waveguides respectively output a group of optical signals with different wavelengths but the same transmittance, and its M output waveguides respectively output one optical signal among the M optical signals with different transmittances, where N and M are both integers greater than or equal to 1, and, N second-stage symmetrical wave combiner / demultiplexer units, wherein the input waveguide of each second-stage symmetrical wave combiner / demultiplexer unit receives a group of optical signals with different wavelengths but the same transmittance, and the output waveguide of each second-stage symmetrical wave combiner / demultiplexer unit outputs a group of optical signals with different wavelengths but the same transmittance; The functional areas of the first-level asymmetric combiner and demultiplexer unit and the N second-level symmetric combiner and demultiplexer units are optimized by reverse design, specifically: a FOM function is established based on the goal of minimizing the difference between the actual output optical loss of each output waveguide of the combiner and demultiplexer unit and the target output optical loss, each sub-wavelength unit in the functional area is traversed, and the sub-wavelength unit material type that maximizes the FOM function value is selected, and the actual output optical loss of the output waveguide of the combiner and demultiplexer unit is obtained by calculating the ratio of the transmittance of the output waveguide and the input waveguide to the optical signal of the same wavelength.

2. According to the asymmetric wave combining and decomposing chip based on reverse design according to claim 1, it is characterized in that: One of the M output waveguides of the first-level asymmetric combiner and demultiplexer is connected to the N+1th second-level symmetric combiner and demultiplexer, and at least two of the M optical signals with different transmittances are transmitted to the input waveguide of the N+1th second-level symmetric combiner and demultiplexer via one of the M output waveguides of the first-level asymmetric combiner and demultiplexer, and the output waveguide of the N+1th second-level symmetric combiner and demultiplexer outputs at least two of the M optical signals with different transmittances by wavelength division.

3. The asymmetric wave combining and decomposing chip based on reverse design according to claim 2, characterized in that: At least one of the N output waveguides of the first-level asymmetric combiner and demultiplexer is connected to the input waveguide of the third-level symmetric combiner and demultiplexer. Part of the optical signals in a group of optical signals with different wavelengths but the same transmittance output by one of the N output waveguides of the first-level asymmetric combiner and demultiplexer is transmitted to a third-level symmetric combiner and demultiplexer. The third-level symmetric combiner and demultiplexer outputs a part of the optical signals in a group of optical signals with different wavelengths but the same transmittance by wavelength division.

4. The asymmetric wave combining and decomposing chip based on reverse design according to claim 2, characterized in that: The FOM function is established based on the goal of minimizing the difference between the actual output optical loss of each output waveguide of the first-stage asymmetric combiner and decomposer and the target output optical loss: FOM=FOM(O1)+FOM(O m+p )+FOM(O m+p+q+1 )+FOM(O m+p+q+2 )+FOM(O m+p+q+r ) +FOM(O m+p+q+s+1 )+FOM(O m+p+q+s+w ), Among them, FOM (O1) is the first output waveguide O1 of the first-stage asymmetric wave combiner and decomposer for wavelengths λ1, λ2, ...λ m The transmittance of a group of optical signals The evaluation function of The input waveguide pair of the first-stage asymmetric wave combiner and decomposer has wavelengths of λ1, λ2, ...λ m The transmittance of a group of optical signals, is the target output optical loss of the first output waveguide O1 of the first-stage asymmetric combiner / decomposer; FOM(O m+p ) is the m+pth output waveguide O of the first-stage asymmetric wave combiner and decomposer m+p For wavelength λ m+p , m+p+1 , …λ m+p+q The transmittance of a group of optical signals The evaluation function of The wavelength of the input waveguide pair of the first-stage asymmetric wave combiner is λ m+p , m+p+1 , …λ m+p+q The transmittance of a group of optical signals, The m+pth output waveguide O of the first-stage asymmetric wave combiner and decomposer m+p Target output optical loss; FOM(O m+p+q+1 ) is the m+p+q+1th output waveguide O of the first-stage asymmetric wave combining and decomposing unit m+p+q+1 For wavelength λ m+p+q+1 The transmittance of the optical signal The evaluation function of The wavelength of the input waveguide pair of the first-stage asymmetric wave combiner and decomposer is λ m+p+q+1 The transmittance of the optical signal, The m+p+q+1th output waveguide O of the first-stage asymmetric wave combiner and decomposer m+p+q+1 Target output optical loss; FOM(O m+p+q+2 ) is the m+p+q+2th output waveguide O of the first-stage asymmetric wave combining and decomposing unit m+p+q+2 For wavelength λ m+p+q+2 The transmittance of the optical signal The evaluation function of The wavelength of the input waveguide pair of the first-stage asymmetric wave combiner is λ m+p+q+2 The transmittance of the optical signal, The m+p+q+2th output waveguide O of the first-stage asymmetric wave combiner and decomposer m+p+q+2 Target output optical loss; FOM(O m+p+q+r ) is the m+p+q+rth output waveguide O of the first-stage asymmetric wave combining and decomposing unit m+p+q+r For wavelength λ m+p+q+r , m+p+q+r+1 , …λ m+p+q+s The transmittance of a group of optical signals The evaluation function of The wavelength of the input waveguide pair of the first-stage asymmetric wave combiner is λ m+p+q+r , m+p+q+r+1 , …λ m+p+q+s The transmittance of a group of optical signals, The m+p+q+rth output waveguide O of the first-stage asymmetric wave combiner and decomposer m+p+q+r Target output optical loss; FOM(O m+p+q+s+1 ) is the m+p+q+s+1th output waveguide O of the first-stage asymmetric wave combining and decomposing unit m+p+q+s+1 For wavelength λ m+p+q+s+1 , m+p+q+s+2 , …λ m+p+q+s+t The transmittance of a group of optical signals The evaluation function of The wavelength of the input waveguide pair of the first-stage asymmetric wave combiner is λ m+p+q+s+1 , m+p+q+s+2 , …λ m+p+q+s+t The transmittance of a group of optical signals, The m+p+q+s+1th output waveguide O of the first-stage asymmetric wave combiner and decomposer m+p+q+s+1 Target output optical loss; FOM(O m+p+q+s+w ) is the m+p+q+s+wth output waveguide O of the first-stage asymmetric wave combining and decomposing unit m+p+q+s+w For wavelength λ m+p+q+s+t+w , m+p+q+s+t+w+1 , …λ n-v , n-v+1 , …λ n The transmittance of a group of optical signals The evaluation function of The wavelength of the input waveguide pair of the first-stage asymmetric wave combiner is λ m+p+q+s+t+w , m+p+q+s+t+w+1 , …λ n-v , n-v+1 , …λ n The transmittance of a group of optical signals, The m+p+q+s+wth output waveguide O of the first-stage asymmetric wave combiner and decomposer m+p+q+s+w The target output optical loss is as follows: c, m, p, q, r, s, t, w, and n are positive integers that increase successively.

5. The asymmetric wave combining and decomposing chip based on reverse design according to claim 4 is characterized in that: According to the interval of the output wavelength of the asymmetric wavelength combining and decomposing chip, the values ​​of c, m, p, q, r, s, t, w and n are adjusted.

6. The asymmetric wave combiner and decoder chip based on reverse design according to any one of claims 1 to 5, characterized in that: The first-stage asymmetric wave combining and decomposing unit is connected to the input waveguide of the second-stage symmetric wave combining and decomposing unit through an S-shaped bending waveguide.

7. The asymmetric wave combiner and decoder chip based on reverse design according to any one of claims 1 to 5, characterized in that: The input waveguides of the first-level asymmetric wave combining and decomposing units are all arranged at the center position of one side of the functional area, and the output waveguides of the first-level asymmetric wave combining and decomposing units are evenly distributed on the other side of the functional area; the input waveguides of the second-level symmetric wave combining and decomposing units are all arranged at the center position of one side of the functional area, and the output waveguides of the second-level symmetric wave combining and decomposing units are evenly distributed on the other side of the functional area.

8. The asymmetric wave combiner and decoder chip based on reverse design according to any one of claims 1 to 5, characterized in that: The asymmetric wave-decomposition chip is prepared by semiconductor technology based on any one of silicon-on-insulator, silicon dioxide-on-silicon, InP, GaAs, polymer, lithium niobate, diamond, and sulfur-based platforms.

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