Splicing filter, splicing method and electronic device

Abstract

The present disclosure provides a splicing filter, a splicing method and an electronic device. The splicing filter comprises a first type filter and a second type filter spliced with the first type filter; the first type filter processes an input signal and outputs the processed signal to the second type filter; wherein the splicing filter is a multi-order super-Gaussian filter. Through the embodiment of the present disclosure, the high performance indicators of the first type filter and the second type filter can be inherited, the performance indicators of the splicing filter can be further improved through the two-stage cascading splicing mode between the first type filter and the second type filter, and the multi-order super-Gaussian filter has a high rectangularity spectrum shape, low cost and is easy to popularize.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of communication, in particular to a spliced filter, a splicing method and an electronic device. BACKGROUND

[0002] A filter is a device or circuit that has a processing effect on a signal, which can pass the useful signal with as little attenuation as possible and attenuate the useless signal as much as possible. However, with the development of communication technology, a single filter is increasingly difficult to meet application requirements, which is particularly evident in the field of optical communication.

[0003] In an optical communication system, as the demand for large-scale cloud services and data center storage and processing is growing, the system of the data center becomes more and more dispersed, and the emergence of artificial intelligence and other applications promotes the development of low-latency, high-bandwidth open optical network interconnection architecture. Considering compatibility with distributed campus networks, metropolitan area networks and telecom service providers, 400ZR interconnection and low-cost coherent transmission module interconnection have emerged. The 400ZR interconnection and low-cost coherent transmission module interconnection adopts dense wavelength division multiplexing technology, which requires high wavelength accuracy and bandwidth accuracy of the filter because the baud rate is high. Moreover, coherent oversampling requires high isolation of the filter. At the same time, in order to ensure the transmission performance of the module, the filter shape has a high rectangularity requirement.

[0004] However, the conventional Arrayed Waveguide Grating (AWG) filter scheme is difficult to achieve the high rectangularity requirement, i.e., it is difficult to simultaneously achieve a wide bandwidth and high isolation, and it is also difficult to achieve high wavelength accuracy and high bandwidth accuracy. Although the Wavelength Selective Switch (WSS) filter scheme can achieve high rectangularity filtering, i.e., it can simultaneously achieve a wide bandwidth and high isolation, and it can also achieve high wavelength accuracy and high bandwidth accuracy requirements, the cost is high and it is not convenient to promote. SUMMARY

[0005] Therefore, the main purpose of the present disclosure is to provide a spliced filter, a splicing method and an electronic device, which can inherit the high performance indicators of the first type filter and the second type filter, and further improve the performance indicators of the spliced filter through two-stage cascading splicing between the first type filter and the second type filter. Moreover, the multi-order super-Gaussian filter has a high rectangularity spectral shape, low cost and is convenient to promote.

[0006] To achieve the above purpose, the technical scheme of the present disclosure is as follows:

[0007] In a first aspect, the embodiments of the present disclosure provide a spliced filter, comprising: a first type of filter and a second type of filter spliced with the first type of filter; the first type of filter processes an input signal and outputs the processed signal to the second type of filter.

[0008] The spliced filter is a multi-order super-Gaussian filter.

[0009] In some embodiments, the first type of filter and the second type of filter each comprise at least one filter.

[0010] The filter frequency response function of the spliced filter is the product of the filter frequency response function of at least one filter of the first type of filter and the filter frequency response function of at least one filter of the second type of filter.

[0011] In some embodiments, at least one filter of the first type of filter and at least one filter of the second type of filter are cascaded to form a multi-stage cascaded structure.

[0012] The filter corresponding to the filter frequency response function of the first stage in the multi-stage cascaded structure has an order of M, and the filter corresponding to the filter frequency response function of the next stage in the multi-stage cascaded structure has an order of N; the filter of the next stage is a filter cascaded after the filter of the first stage.

[0013] M and N are positive numbers, M is greater than the order of the spliced filter, and N is less than the order of the spliced filter.

[0014] In some embodiments, at least one filter comprises at least one Michelson interferometer; or,

[0015] At least one filter comprises at least one arrayed waveguide grating; or,

[0016] At least one filter comprises the Michelson interferometer and the arrayed waveguide grating, and the arrayed waveguide grating is cascaded with the Michelson interferometer.

[0017] In some embodiments, the filter comprises a Michelson interferometer; a first index parameter of the spliced filter is determined by the Michelson interferometer; wherein the first index parameter comprises: center wavelength accuracy, bandwidth, and / or adjacent isolation.

[0018] In some embodiments, the filter comprises an arrayed waveguide grating; a second index parameter of the spliced filter is determined by the arrayed waveguide grating; wherein the second index parameter comprises: non-adjacent isolation.

[0019] In some embodiments, the spliced filter is a three-order super-Gaussian filter.

[0020] In some embodiments, an insertion loss value of the spliced filter is a sum of an insertion loss value of the first type filter and an insertion loss value of the second type filter.

[0021] In a second aspect, the embodiments of the present disclosure provide a splicing method, comprising:

[0022] obtaining a first type filter and a second type filter;

[0023] splicing the first type filter and the second type filter to obtain a spliced filter;

[0024] The spliced filter is a multi-order super-Gaussian filter.

[0025] In some embodiments, the first type filter and the second type filter each include at least one filter.

[0026] The at least one filter includes at least one Michelson interferometer; or

[0027] The at least one filter includes at least one arrayed waveguide grating; or

[0028] The at least one filter includes the Michelson interferometer and the arrayed waveguide grating, and the arrayed waveguide grating is cascaded with the Michelson interferometer.

[0029] In some embodiments, a first index parameter of the spliced filter is determined by the Michelson interferometer, and a second index parameter of the spliced filter is determined by the arrayed waveguide grating.

[0030] The first index parameter includes center wavelength accuracy, bandwidth, and / or adjacent isolation, and the second index parameter includes non-adjacent isolation.

[0031] In a third aspect, the embodiments of the present disclosure provide an electronic device including the spliced filter of the first aspect.

[0032] In the embodiments of the present disclosure, the spliced filter includes a first type filter and a second type filter spliced with the first type filter, and the first type filter outputs a processed signal to the second type filter. The spliced filter is a multi-order super-Gaussian filter. That is, the spliced filter can inherit the high performance indexes of the first type filter and the second type filter, and further improve the performance indexes of the spliced filter through two-stage cascaded splicing between the first type filter and the second type filter. Moreover, the multi-order super-Gaussian filter has a high rectangularity spectrum shape, low cost, and is easy to promote. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of a splicing filter according to an exemplary embodiment of the present disclosure. Figure One ;

[0034] Figure 2 This is a schematic diagram of the structure of a splicing filter according to an exemplary embodiment of the present disclosure. Figure Two ;

[0035] Figure 3 This is a schematic diagram of the structure of a splicing filter according to an exemplary embodiment of the present disclosure. Figure Three ;

[0036] Figure 4 This is a schematic diagram illustrating the principle of a splicing filter according to an exemplary embodiment of the present disclosure;

[0037] Figures 5a-5b This is a schematic diagram of the structure of a first type of filter according to an exemplary embodiment of the present disclosure;

[0038] Figures 6a-6b This is a schematic diagram of the structure of a second type of filter according to an exemplary embodiment of the present disclosure;

[0039] Figure 7 This is a schematic diagram of the structure of a splicing filter according to an exemplary embodiment of the present disclosure. Figure Four ;

[0040] Figure 8 This is a transmission spectrum of an MGTI comb filter illustrated according to an exemplary embodiment of the present disclosure;

[0041] Figure 9 This is a super Gaussian fitting curve of the transmission spectrum of an MGTI comb filter shown in an exemplary embodiment of the present disclosure;

[0042] Figure 10 This is a schematic diagram illustrating the definitions of center wavelength, center wavelength accuracy, and center wavelength insertion loss according to an exemplary embodiment of the present disclosure;

[0043] Figure 11 This is a schematic diagram illustrating the definition of in-band insertion loss flatness according to an exemplary embodiment of the present disclosure;

[0044] Figure 12 This is a schematic diagram illustrating a bandwidth definition according to an exemplary embodiment of the present disclosure;

[0045] Figure 13 This is a schematic diagram illustrating the definition of isolation according to an exemplary embodiment of this disclosure;

[0046] Figure 14is a transmission spectrum diagram of an AWG wavelength division multiplexer according to an exemplary embodiment of the present disclosure;

[0047] Figure 15 is a partial enlarged view of the transmission spectrum of the AWG wavelength division multiplexer according to an exemplary embodiment of the present disclosure;

[0048] Figure 16 is a super-Gaussian fitting curve diagram of the transmission spectrum of the AWG wavelength division multiplexer according to an exemplary embodiment of the present disclosure;

[0049] Figure 17 is a transmission spectrum diagram of a spliced filter according to an exemplary embodiment of the present disclosure;

[0050] Figure 18 is a partial enlarged view of the transmission spectrum of the spliced filter according to an exemplary embodiment of the present disclosure;

[0051] Figure 19 is a super-Gaussian fitting curve diagram of the transmission spectrum of the spliced filter according to an exemplary embodiment of the present disclosure;

[0052] Figure 20 is a transmission spectrum comparison diagram of an MGTI comb filter, an AWG wavelength division multiplexer and a spliced filter according to an exemplary embodiment of the present disclosure;

[0053] Figure 21 is a partial enlarged view of the transmission spectrum comparison diagram of the MGTI comb filter, the AWG wavelength division multiplexer and the spliced filter according to an exemplary embodiment of the present disclosure;

[0054] Figure 22 is a flowchart of a splicing method according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0055] In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure clearer, the specific technical solutions of the present application will be further described in detail below with reference to the drawings in the embodiments of the present disclosure. The following embodiments are used to illustrate the present disclosure, but not to limit the scope of the present disclosure.

[0056] The technical solutions provided by various embodiments of the present disclosure will be described in detail below with reference to the drawings.

[0057] In the prior art, 400ZR interconnection and low-cost coherent transmission module interconnection adopt dense wavelength division multiplexing technology, because the baud rate is high, the wavelength accuracy and bandwidth accuracy of the filter are high; and coherent oversampling, the isolation of the filter is also high; at the same time, in order to ensure the transmission performance of the module, the filter shape has a high rectangularity requirement.

[0058] However, the conventional array waveguide grating filter scheme is difficult to achieve high rectangularity requirements, that is, it is difficult to simultaneously achieve wide bandwidth and high isolation, and it is also difficult to achieve high wavelength accuracy and high bandwidth accuracy; the WSS filter scheme can achieve high rectangularity filtering, that is, it can simultaneously achieve wide bandwidth and high isolation, and can also achieve high wavelength accuracy and high bandwidth accuracy requirements, but the cost is high and is not convenient for promotion.

[0059] Based on this, the embodiment of the present disclosure provides a spliced filter. Figure 1 The structure of the spliced filter according to an exemplary embodiment of the present disclosure is shown in Figure One As shown in Figure 1 The spliced filter can include:

[0060] The first type of filter and the second type of filter spliced with the first type of filter; the first type of filter processes the input signal and outputs it to the second type of filter;

[0061] Among them, the spliced filter is a multi-order super-Gaussian filter.

[0062] In the embodiment of the present disclosure, the spectral width of the transmission spectrum of the second type of filter is greater than the spectral width of the transmission spectrum of the first type of filter; for example, the spectral width of the transmission spectrum of the second type of filter can be twice the spectral width of the transmission spectrum of the first type of filter.

[0063] It can be understood that the first type of filter and the second type of filter have reciprocity, that is, the characteristics of the first type of filter and the second type of filter can be exchanged.

[0064] For example, the first type of filter and the second type of filter can be interleavers (INT) and / or wavelength division multiplexers (WDM). That is, the first type of filter and the second type of filter can both be interleavers; or the first type of filter and the second type of filter can both be wavelength division multiplexers; or the first type of filter can be an interleaver and the second type of filter can be a wavelength division multiplexers; or the first type of filter can be a wavelength division multiplexer and the second type of filter can be an interleaver; and so on.

[0065] A comb filter consists of many passbands and stopbands arranged at regular frequency intervals. It allows signals within a specific frequency range to pass through; its characteristic curve resembles a comb, hence the name. A wavelength division multiplexer (WDM) combines a series of information-carrying signals of different wavelengths into a single beam, transmits it along a single optical fiber, and then separates the signals at the receiving end using a specific method.

[0066] Here, when the first type of filter is a comb filter and the second type of filter is a wavelength division multiplexer, the first type of filter may include odd channels and even channels; the second type of filter may include a first wavelength division multiplexer and a second wavelength division multiplexer; the first wavelength division multiplexer is connected to the odd channel of the first type of filter, and the second wavelength division multiplexer is connected to the even channel of the second type of filter; the signal input to the first type of filter is respectively input to the first wavelength division multiplexer through the odd channel and input to the second wavelength division multiplexer through the even channel; wherein, the channel spacing of the first wavelength division multiplexer and the second wavelength division multiplexer is the same, and both are twice the channel spacing of the first type of filter.

[0067] For example, such as Figure 2 As shown, the comb filter INT can include odd channels and even channels with a frequency interval of f. The wavelength of the optical signal output from the odd channel can be represented as {λ1, λ3, ..., λ...} 2n-1 The wavelength of the optical signal output from the even channel can be represented as {λ2, λ4, ..., λ}. 2n Correspondingly, the frequency spacing between the first wavelength division multiplexer (WDM1) and the second wavelength division multiplexer (WDM2) can both be 2f; the wavelength of the optical signal output by the first wavelength division multiplexer (WDM1) can be the same as the wavelength output by the odd channel, i.e., {λ1, λ3, ..., λ...} 2n-1 The wavelength of the optical signal output by the second wavelength division multiplexer (WDM2) can be the same as the wavelength of the odd channel output, i.e., {λ2, λ4, ..., λ...}. 2n}

[0068] In this embodiment of the disclosure, the splicing filter can be a second-order super-Gaussian filter, a third-order super-Gaussian filter, or a 3.5-order super-Gaussian filter, etc.

[0069] In the 400G ZR network standard, the transmission spectrum shape of the above-mentioned multi-order super-Gaussian filter has requirements for high center wavelength accuracy, wide bandwidth, high bandwidth accuracy and high isolation; the above-mentioned splicing filter has a waveform with high rectangularity to meet the requirements of the multi-order super-Gaussian filter.

[0070] Among them, 400G ZR is a network implementation protocol developed by the Optical Internetworking Forum (OIF) for pluggable digital coherent optical communication modules.

[0071] In one embodiment, the transmission spectrum shape of the first type of filter can be a square wave; for example, the transmission spectrum shape of the comb filter can be rectangular, so that the splicing filter can inherit the high rectangularity waveform of the comb filter.

[0072] Embodiments of this disclosure provide a splicing filter, comprising: a first type of filter and a second type of filter spliced ​​with the first type of filter; the first type of filter processes the input signal and outputs it to the second type of filter; wherein, the splicing filter is a multi-order super-Gaussian filter. In other words, by splicing the first type of filter and the second type of filter, the splicing filter can inherit the high performance indicators of both types of filters, while further improving the performance indicators of the splicing filter through a two-stage cascade splicing method between the first and second types of filters. Moreover, the multi-order super-Gaussian filter has a highly rectangular spectral shape, low cost, and is easy to promote.

[0073] For example, in one embodiment of this disclosure, such as Figure 3 As shown, the first type of filter may include a Michelson interferometer (MI), and the second type of filter may include an arrayed waveguide grating (AWG), thereby enabling the splicing filter to realize a multi-order super-Gaussian splicing filter, which meets the performance requirements in the 400G ZR standard.

[0074] The aforementioned Michelson interferometer can be further divided into the Michelson-Gires-Tournois Interferometer (MGTI), which is the most common type of optical interferometer. The principle of a Michelson interferometer is that an incident beam of light is split into two beams by a beam splitter, and each beam is reflected back by its corresponding plane mirror. Because these two beams have the same frequency, the same direction of vibration, and a constant phase difference (i.e., satisfying the interference condition), they can interfere. Different optical path lengths of the two beams during interference can be achieved by adjusting the length of the interference arms and changing the refractive index of the medium, thus forming different interference patterns. When the plane mirrors in a Michelson interferometer are replaced with Gires-Tournois resonant cavities, it is called a Michelson-Gires-Tournois interferometer.

[0075] The aforementioned arrayed waveguide grating is a type of discrete passive optical integrated device, consisting of an input waveguide, an input planar waveguide, an arrayed waveguide, an output planar waveguide, and an output waveguide.

[0076] In this embodiment of the disclosure, the Michelson-GT cavity interferometer described above has performance indicators of high center wavelength accuracy, wide bandwidth, high bandwidth accuracy, and high adjacent isolation; the arrayed waveguide grating described above has performance indicators of high non-adjacent isolation.

[0077] In some embodiments, the splicing filter is a third-order super-Gaussian filter, which can better meet the requirements of the high rectangularity waveform of the splicing filter.

[0078] Here, both the first type of filter and the second type of filter mentioned above can be super-Gaussian filters; the filtering frequency response function of a super-Gaussian filter can be expressed as: |H(f)| 2 =aexp[((f-f0)] 2 / b) m ].

[0079] Where exp represents an exponential function with base e in advanced mathematics, for example, exp{F(X)} is e raised to the power of F(X); a and b represent coefficients, f0 represents the center frequency, and m represents the order; when m = 3, the corresponding function can be a third-order super-Gaussian filter frequency response function.

[0080] In one embodiment of this disclosure, both the first type of filter and the second type of filter may include at least one filter;

[0081] The filtering frequency response function of the spliced ​​filter can be the product of the filtering frequency response function of at least one of the first type of filters and the filtering frequency response function of at least one of the second type of filters.

[0082] Thus, the filtering frequency response function of the spliced ​​filter can be calculated from the filtering frequency response function of at least one filter in the first type of filter and the filtering frequency response function of at least one filter in the second type of filter, so as to obtain a multi-order super Gaussian filter.

[0083] For example, the two-stage cascade between one filter in the first type of filter and two filters in the second type of filter can be a linear time-invariant system, such as... Figure 4 As shown, the filtering frequency response function of the splicing filter can be the product of the filtering frequency response function of the first type filter MGTI and the filtering frequency response function of the second type filter AWG, as shown in formula (1); after converting formula (1) into logarithmic decibels (dB), the product becomes a sum, as shown in formula (2).

[0084]

[0085]

[0086] Among them, P in (f) Power can be input to the input port of the above splicing filter, P out (f) can be the output power of the above splicing filter, and the filtering frequency response function of the above splicing filter can be the ratio of the output power of the output port to the input power of the input port; H1 2 (f) represents the filter frequency response function of the first type of filter mentioned above, H2 2 (f) represents the filtering frequency response function of the second type of filter mentioned above.

[0087] In some embodiments, at least one of the filters of the first type of filter is cascaded with at least one of the filters of the second type of filter to form a multi-stage cascaded structure;

[0088] In the multi-stage cascaded structure, the order of the filter frequency response function corresponding to the first stage filter is M, and the order of the filter frequency response function corresponding to the next stage filter in the multi-stage cascaded structure is N; the next stage filter is a filter cascaded after the first stage filter.

[0089] Where M and N are positive numbers, and M is greater than the order of the splicing filter, while N is less than the order of the splicing filter.

[0090] In this way, the performance of the splicing filter can be better improved by using a multi-stage cascaded structure while ensuring that the insertion loss of the splicing filter is not affected. Furthermore, the order of the splicing filter can be obtained by using the order of the filter frequency response function corresponding to the first-stage filter and the order of the filter frequency response function corresponding to the next-stage filter, so that the order of the splicing filter meets the requirements of high rectangularity waveforms.

[0091] In this embodiment, a multi-order super-Gaussian filter can be obtained by multiplying the order of the filter frequency response function corresponding to the first-stage filter with the order of the filter frequency response function corresponding to the next-stage filter through multi-stage cascading. For example, if one filter MGTI of the first type of filter is cascaded with two filters AWG of the second type of filter to form a two-stage cascaded structure, then the first-stage filter can be MGTI, and the next-stage filter can be AWG; the order of the spliced ​​filter can be 3, the order of the filter frequency response function corresponding to MGTI can be greater than 3, and the order of the filter frequency response function corresponding to AWG can be less than 3.

[0092] In one embodiment of this disclosure, at least one of the filters includes at least one Michelson interferometer; or, at least one of the filters includes at least one arrayed waveguide grating; or, at least one of the filters includes the Michelson interferometer and the arrayed waveguide grating, wherein the arrayed waveguide grating is cascaded with the Michelson interferometer.

[0093] In this way, the performance of the splicing filter can be better improved by using a cascaded structure of Michelson interferometers and / or arrayed waveguide gratings, while ensuring that the insertion loss of the splicing filter is not affected.

[0094] In this embodiment of the disclosure, such as Figure 5a As shown, the first type of filter described above may include a Michelson interferometer; or, as... Figure 5b As shown, the first type of filter described above may include three Michelson interferometers; alternatively, the first type of filter may be composed of n cascaded Michelson interferometers; or, the first type of filter may include at least one Michelson interferometer cascaded with at least one arrayed waveguide grating. Similarly, as... Figure 6a As shown, the second type of filter described above may include an arrayed waveguide grating; or, as... Figure 6b As shown, the second type of filter may include three arrayed waveguide gratings; or, the second type of filter may be composed of n cascaded arrayed waveguide gratings; or, the second type of filter may include at least one Michelson interferometer cascaded with at least one arrayed waveguide grating.

[0095] In some embodiments, the first type of filter may include one arrayed waveguide grating, three arrayed waveguide gratings, or n arrayed waveguide gratings cascaded together; or, the first type of filter may include at least one Michelson interferometer cascaded with at least one arrayed waveguide grating. The second type of filter may include one Michelson interferometer, three Michelson interferometers, or n Michelson interferometers cascaded together; or, the second type of filter may include at least one Michelson interferometer cascaded with at least one arrayed waveguide grating.

[0096] For example, such as Figure 7As shown, when the first type of filter includes three Michelson interferometers and the second type of filter includes four arrayed waveguide gratings, the first type of filter and the second type of filter are cascaded to form a three-stage cascaded structure. Specifically, one Michelson interferometer constitutes the first-stage filter, two Michelson interferometers constitute the second-stage filter, and four arrayed waveguide gratings constitute the third-stage filter. Correspondingly, the channel spacing of the second-stage filter can be twice the channel spacing of the first-stage filter, and the channel spacing of the third-stage filter can be twice the channel spacing of the second-stage filter. In this case, the order of the spliced ​​filter can be 3, the order of the filtering frequency response function corresponding to the first-stage filter can be greater than 3, and the orders of the filtering frequency response functions corresponding to the second-stage filter and the third-stage filter can both be less than 3.

[0097] It should be noted that the number of the first type of filter and the second type of filter can be set according to the specific situation of multi-stage cascading in actual applications, and this embodiment does not impose any restrictions.

[0098] In one embodiment of this disclosure, the insertion loss of the signal in the splicing filter is the sum of the insertion loss of the signal in the first type of filter and the insertion loss of the signal in the second type of filter, thereby enabling the splicing filter to inherit the performance indicators of both the first and second type of filters.

[0099] Insertion loss, also known as insertion load loss, refers to the loss of load power at a point in a transmission system due to the insertion of a component or device. It is expressed as the difference, in decibels, between the power received by the load before insertion and the power received by the same load after insertion. The concept of insertion loss is generally used in filters to represent the loss of signal power before and after using the filter.

[0100] Here, the insertion loss value of the signal in the splicing filter can refer to the difference between the output power at the output port and the input power at the input port of the splicing filter, in dB.

[0101] In some embodiments, the filter includes a Michelson interferometer; a first specification parameter of the splicing filter is determined by the Michelson interferometer; wherein the first specification parameter includes: center wavelength accuracy, bandwidth, and / or adjacent isolation.

[0102] In this embodiment of the disclosure, the Michelson interferometer described above has performance indicators such as high center wavelength accuracy, wide bandwidth, high bandwidth accuracy, and high adjacent isolation; the splicing filter described above can inherit the performance indicators of the Michelson interferometer such as high center wavelength accuracy, wide bandwidth, high bandwidth accuracy, and high adjacent isolation.

[0103] In some embodiments, the filter includes an arrayed waveguide grating; a second performance parameter of the spliced ​​filter is determined by the arrayed waveguide grating; wherein the second performance parameter includes: non-adjacent isolation.

[0104] In this embodiment of the disclosure, the transmission spectrum of the arrayed waveguide grating is flat and has a high non-adjacent isolation performance index; the splicing filter can inherit the high non-adjacent isolation performance index of the arrayed waveguide grating.

[0105] To facilitate understanding, the above splicing filters will be explained in detail below using the first type of filter, which includes a Michelson-GT cavity interferometer, and the second type of filter, which includes an arrayed waveguide grating, as examples.

[0106] For example, suppose the desired number of channels for the splicing filter is 64, the frequency spacing is 75 GHz, and the starting frequency is f. ITU-1 =196100GHz (Termination frequency is f) ITU-64 =f ITU-1 -75×63=191375GHz), the corresponding center wavelength of the International Telecommunication Union (ITU) is λ. ITU-1 =c / f ITU-1 = 1528.773 nanometers (nm) (terminus wavelength is λ) ITU-64 =c / f ITU-64 =1566.518nm), center wavelength accuracy requirement is within [-4, 4] GHz, insertion loss requirement is within 6.5dB, channel loss unevenness requirement is within 2.5dB, 3dB full bandwidth requirement is within [70, 76] GHz, 10dB full bandwidth requirement is within [85, 94] GHz, adjacent isolation requirement is above 30dB, and non-adjacent isolation requirement is above 25dB.

[0107] Based on the above requirements for splicing filters, assuming a Michelson-GT cavity interferometer with 1 input and 2 outputs, the two output channels are the odd channel and the even channel, where the starting wavelength of the odd channel can be λ. odd-1 =λ ITU-1 =1528.773nm(f odd-1 =f ITU-1 =196100GHz), the termination wavelength of the even channel can be λ even-32 =λ ITU-64 =1566.518nm(f even-32 =f ITU-64 =191375GHz), the termination wavelength of the odd channel can be λ odd-32 =c / (f even-32+75)=1565.905nm, the starting wavelength of the even channel can be λ even-1 =c / (f odd-1 -75)=1529.358nm, therefore, the frequency spacing of both the odd and even channels is 150GHz, and the spacing between the odd and even channels is 75GHz; correspondingly, the number of channels of the two arrayed waveguide gratings is 32, the frequency spacing is 150GHz, and the center wavelength and frequency spacing of the two arrayed waveguide gratings correspond to the odd and even channels of the Michelson-GT cavity interferometer, that is, the starting wavelength of the odd channel is 1528.773nm and the ending wavelength is 1565.905nm, and the starting wavelength of the even channel is 1529.358nm and the ending wavelength is 1566.518nm.

[0108] It is understandable that the correlation between the performance parameters of the Michelson-GT cavity interferometer, the arrayed waveguide grating, and the splicing filter is obtained through theoretical analysis. Then, based on the correlation, and given the performance parameters of the splicing filter, the performance parameters of the Michelson-GT cavity interferometer and the arrayed waveguide grating are deduced. Here, the performance parameters can represent the range of values ​​for the performance parameters.

[0109] In some embodiments, the transmission spectrum of the MGTI comb filter is as follows: Figure 8 As shown, the horizontal axis represents wavelength, and the conversion relationship between wavelength λ and frequency f is λ = c / f, where c represents the speed of light constant, and c = 299792458 m / s; the vertical axis represents transmittance, and transmittance has an inverse relationship with insertion loss. Its spectral curve fitting is as follows: Figure 9 As shown, the dashed circle represents the measured transmission spectrum of the MGTI comb filter. The horizontal axis represents the frequency in GHz, and the vertical axis represents the transmittance, which is not converted to dB and has a range of [0,1]. The solid line is the fitted transmission curve, and the order of the fitted super-Gaussian curve is greater than 3.

[0110] Figure 10 This is a schematic diagram illustrating the definition of center wavelength and center wavelength accuracy according to an exemplary embodiment of this disclosure. Figure 10 As shown, the 3dB center wavelength λ c It can be defined as the wavelength value corresponding to the center of the spectral range covered by a 3dB decrease in center wavelength insertion loss, and the center wavelength insertion loss IL ITU The insertion loss value corresponding to the ITU center wavelength is defined as follows: the center wavelength accuracy Δλ is defined as 3dB center wavelength λ. c With ITU center wavelength λ ITU The difference, i.e., Δλ = λ c -λ ITU .

[0111] according to Figure 10 Definition, combination Figure 8 The transmission spectrum of the MGTI comb filter was used to calculate the insertion loss value corresponding to the ITU center wavelength, i.e., the center wavelength insertion loss IL. ITU-MGTI =0.35dB, the corresponding wavelength values ​​after a 3dB decrease in center wavelength are 1528.491nm and 1529.07nm, respectively. Based on this, the center wavelength after a 3dB decrease is as shown in formula (3):

[0112] λ c-MGTI =(1528.491+1529.07) / 2=1528.781nm (3)

[0113] The center wavelength accuracy is shown in formula (4):

[0114] △λ MGTI =1528.781-1528.773=0.008nm=8pm (4)

[0115] If converted to frequency precision, the calculation formula (5) is as follows:

[0116] △f MGTI =c / 1528.781-196100=-0.98GHz (5)

[0117] Assuming that the loss ripple within the channel is defined as the difference between the maximum and minimum insertion loss within the effective bandwidth of the channel, such as... Figure 11 As shown, assuming the effective bandwidth of the channel is + / -32GHz, the maximum insertion loss within the + / -32GHz effective bandwidth is 1.51dB and the minimum is 0.35dB. The loss unevenness within the channel is calculated as shown in formula (6):

[0118] Ripple MGTI =1.51-0.35=1.16dB (6)

[0119] Assuming the ndB bandwidth is defined as the spectral width covered by the center wavelength insertion loss decrease ndB, such as Figure 12 As shown, the full bandwidth = BW1 + BW2, and the net bandwidth = 2 × min(BW1, BW2). This embodiment of the present disclosure takes the full bandwidth index as an example. The wavelength values ​​corresponding to the 3dB decrease in center wavelength insertion loss are 1528.491nm and 1529.07nm, respectively. The wavelength values ​​corresponding to the 10dB decrease in center wavelength insertion loss are 1528.429nm and 1529.128nm, respectively. Based on this, the 3dB bandwidth and 10dB bandwidth are calculated as shown in formulas (7) and (8), respectively:

[0120] BW 3-MGTI=c / 1528.491-c / 1529.07=74.27GHz (7)

[0121] BW 10-MGTI =c / 1528.429-c / 1529.128=88.66GHz (8)

[0122] Assuming that Adjacent Isolation (AI) is defined as the difference between the insertion loss of the center wavelength of one channel and the insertion loss of the center wavelength of the adjacent channel, such as... Figure 13 As shown, the adjacent isolation is typically the minimum of the left and right adjacent isolation. By definition, the insertion loss at the channel center wavelength is 0.35 dB. Since this embodiment selects the first channel, the wavelengths of the left adjacent channels are not used; therefore, only the right adjacent channel isolation is considered. The insertion loss at the center wavelength of the right adjacent channel is 31.63 dB. Therefore, the adjacent isolation of MGTI is calculated to be AI. MGTI =31.63-0.35=31.28dB.

[0123] The transmission spectrum of the arrayed waveguide grating provided in the embodiments of this disclosure is as follows: Figure 14 As shown, a magnified view of the area is as follows: Figure 15 As shown, the horizontal axis represents wavelength, and the vertical axis represents transmittance. Transmittance is inversely related to insertion loss. The transmission spectrum curve is fitted as follows: Figure 16 As shown, the dashed circle represents the measured transmission spectrum of the arrayed waveguide grating. The horizontal axis represents the frequency in GHz, and the vertical axis represents the transmittance, which is not converted to dB and has a range of [0,1]. The solid line is the fitted transmission curve, and the order of the fitted super-Gaussian curve is less than 3. Although the channel spacing of the arrayed waveguide grating is 150 GHz, the analysis is performed using a 75 GHz channel spacing. The focus is on the center wavelength, center wavelength accuracy, center wavelength insertion loss, channel loss flatness, and non-adjacent isolation. Based on the above definitions, the center wavelength of the arrayed waveguide grating is calculated as shown in formula (9):

[0124] λ c-AWG =(1528.245+1529.243) / 2=1528.744nm (9)

[0125] The center wavelength accuracy is shown in formula (10):

[0126] △λ AWG =1528.744-1528.773=-0.029nm=-29pm (10)

[0127] If converted to frequency precision, the calculation formula (11) is as follows:

[0128] △fAWG =c / 1528.744-196100=3.77GHz (11)

[0129] Center wavelength insertion loss IL ITU-AWG = 4.54dB, the channel loss unevenness is as shown in formula (12):

[0130] Ripple AWG =4.66-4.48=0.18dB (12)

[0131] Assuming that non-adjacent isolation (NI) is defined as the difference between the insertion loss of the center wavelength of one channel and the insertion loss of the center wavelength of a non-adjacent channel, such as... Figure 12 As shown, the non-adjacent isolation is typically taken as the minimum of all non-adjacent isolation values. By definition, the insertion loss at the center wavelength of the channel is 4.54 dB, and the minimum insertion loss at the center wavelength of all non-adjacent channels is 49.09 dB. Therefore, the non-adjacent isolation of the arrayed waveguide grating is calculated to be NI. AWG =49.09-4.54=44.55dB.

[0132] The transmission spectrum of the spliced ​​filter is as follows: Figure 17 As shown, a magnified view of the area is as follows: Figure 18 As shown, the transmission spectrum curve is fitted, as follows: Figure 19 As shown, the dashed circle represents the measured transmission spectrum of the spliced ​​filter. The horizontal axis represents frequency in GHz, and the vertical axis represents transmittance, which is not converted to dB and ranges from [0,1]. The solid line is the fitted transmission curve, and the order of the fitted super-Gaussian curve is 3. A comparison of the transmission spectra of the MGTI comb filter, AWG wavelength division multiplexer, and spliced ​​filter is shown below. Figure 20 As shown, Figure 20 Local magnification, such as Figure 21 As shown, the transmission spectrum of the spliced ​​filter is the sum of the dB values ​​of the transmission spectra of the MGTI comb filter and the AWG wavelength division multiplexer.

[0133] Based on the above index definition, the 3dB center wavelength of the splicing filter is calculated as shown in formula (13):

[0134] λ c-MGTT+AWG =(1528.492+1529.061) / 2=1528.777nm (13)

[0135] The center wavelength accuracy is shown in formula (14):

[0136] △λ MGTT+AWG =1528.777-1528.773=0.004nm=4pm (14)

[0137] If converted to frequency precision, the calculation formula (15) is as follows:

[0138] △f MGTT+AWG =c / 1528.773-196100=0.05GHz (15)

[0139] Therefore, the center wavelength of the splicing filter is between MGTI and AWG, that is, the center wavelength accuracy is between MGTI and AWG, but close to MGTI.

[0140] The center wavelength insertion loss of the splicing filter is 5.19dB, which is approximately the sum of the insertion loss of MGTI (0.35dB) and AWG (4.54dB). The extra 0.3dB can be attributed to factors such as fusion splicing loss and testing errors during fiber splicing.

[0141] The loss unevenness within the splicing filter channel is shown in formula (16):

[0142] Ripple MGTT+AWG =6.53-5.14=1.39dB (16)

[0143] From formulas (6), (12) and (16), it can be obtained that the loss unevenness in the splicing filter channel can be approximately equal to the sum of the loss unevenness in the MGTI channel (1.16dB) and the loss unevenness in the AWG channel (0.18dB).

[0144] The 3dB bandwidth and 10dB bandwidth of the splicing filter are shown in formulas (17) and (18), respectively:

[0145] BW 3-MGTT+AWG =c / 1528.492-c / 1529.061=72.99GHz (17)

[0146] BW 10-MGTT+AWG =c / 1528.431-c / 1529.12=88.38GHz (18)

[0147] From formulas (7) and (8), (17) and (18), it can be seen that the bandwidth of the splicing filter is referenced to the bandwidth index of MGTI, and is slightly lower than that of MGTI.

[0148] The adjacent isolation AI of the splicing filter MGTT+AWG =42.89-5.19=37.7dB. The adjacent isolation of the splicing filter is referenced from the adjacent isolation index of MGTI. Specifically, it is better than the adjacent isolation of MGTI by 31.28dB.

[0149] Non-adjacent isolation NI of splicing filtersMGTT+AWG =49.85-5.19=44.66dB, which is comparable to the non-adjacent isolation of AWG, which is 44.55dB.

[0150] In other words, the first performance parameters of the splicing filter, such as center wavelength accuracy, bandwidth and / or adjacent isolation, are determined by the first type of filter. The second performance parameters of the splicing filter, such as non-adjacent isolation, are determined by the second type of filter. The insertion loss of the splicing filter is jointly determined by the first and second types of filters and is the sum of the insertion loss values ​​of the first and second types of filters.

[0151] The embodiments of this disclosure provide a splicing filter that, by splicing a first type of filter and a second type of filter, can inherit the high rectangularity channel transmission spectrum of the first type of filter while simultaneously reducing the transmission spectrum of adjacent channels by cascading the second type of filter, thereby improving the adjacent isolation of the splicing filter; it also inherits the non-adjacent channel transmission spectrum of the second type of filter, exhibiting good non-adjacent isolation performance, and the splicing filter has low production cost and is easy to promote.

[0152] Figure 22 This is a flowchart illustrating a splicing method according to an exemplary embodiment of the present disclosure, such as... Figure 22 As shown, the splicing method of this disclosure embodiment may include the following steps:

[0153] Step 110: Obtain the first type of filter and the second type of filter;

[0154] Step 120: Combine the first type of filter and the second type of filter to obtain a combined filter;

[0155] The splicing filter is a multi-order super-Gaussian filter.

[0156] In step 110, the first type of filter may include a Michelson interferometer or an arrayed waveguide grating, and the second type of filter may also include a Michelson interferometer or an arrayed waveguide grating.

[0157] In step 120, the splicing filter can inherit the high rectangularity channel transmission spectrum of the Michelson interferometer, as well as the high center wavelength accuracy, wide bandwidth, high bandwidth accuracy and / or high adjacent isolation of the Michelson interferometer, and also inherit the high non-adjacent isolation index of the arrayed waveguide grating.

[0158] In this embodiment, the first performance parameter of the splicing filter is determined by the Michelson interferometer; the second performance parameter of the splicing filter is determined by the arrayed waveguide grating; the first performance parameter includes: center wavelength accuracy, bandwidth, and / or adjacent isolation; the second performance parameter includes: non-adjacent isolation. This better meets the high rectangularity waveform requirements of the splicing filter.

[0159] The embodiments of this disclosure provide a splicing method that can inherit the high performance indicators of both the first and second type filters by splicing them together. At the same time, the performance indicators of the spliced ​​filter can be further improved by the two-stage cascade splicing between the first and second type filters. Moreover, the multi-order super Gaussian filter has a high rectangularity spectral shape, low cost, and is easy to promote.

[0160] In some embodiments, both the first type of filter and the second type of filter include at least one filter; at least one of the filters includes at least one Michelson interferometer; or, at least one of the filters includes at least one arrayed waveguide grating; or, at least one of the filters includes the Michelson interferometer and the arrayed waveguide grating, wherein the arrayed waveguide grating is cascaded with the Michelson interferometer.

[0161] In this way, while ensuring the insertion loss of the splicing filter is minimized, the performance of the splicing filter can be better improved by using a multi-stage cascaded structure of at least one Michelson interferometer and / or at least one arrayed waveguide grating.

[0162] The embodiments of this disclosure provide a splicing method that, through the splicing of a first type of filter and a second type of filter, allows the spliced ​​filter to inherit the high rectangularity channel transmission spectrum of the first type of filter while simultaneously reducing the transmission spectrum of adjacent channels by cascading the second type of filter, thereby improving the adjacent isolation of the spliced ​​filter. Furthermore, it also inherits the non-adjacent channel transmission spectrum of the second type of filter, exhibiting good non-adjacent isolation performance. In addition, the performance of the spliced ​​filter can be further improved by multi-stage cascading splicing between the first and second types of filters, better suppressing crosstalk between different signals. Simultaneously, the multi-order super-Gaussian filter has a high rectangularity spectral shape, low cost, and is easy to promote.

[0163] This disclosure also proposes an electronic device including the splicing filter described in the embodiments described above.

[0164] Here, the electronic device can be active in various practical application scenarios, such as image and video acquisition and fiber optic communication. This electronic device includes, but is not limited to, smart terminals. Smart terminals can include, but are not limited to, mobile terminals or portable electronic devices. Mobile terminals include, but are not limited to, mobile phones and tablets; portable electronic devices include, but are not limited to, smartwatches. This disclosure does not impose any limitations on these embodiments.

[0165] In this embodiment of the disclosure, the splicing filter in the electronic device can separate the acquired optical signal into chroma and luminance signals during image acquisition to obtain richer chroma and luminance information. The splicing filter in the electronic device can also separate the acquired optical fiber signal into sub-signals containing multiple center wavelengths during optical fiber communication, thereby improving the communication capacity during optical signal transmission.

[0166] In the several embodiments provided in this disclosure, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components may be combined, or integrated into another system, or some features may be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed may be through some interfaces, and the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0167] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0168] Furthermore, in the various embodiments of this disclosure, all functional units can be integrated into one processing module, or each unit can be a separate unit, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or in a combination of hardware and software functional units. Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0169] The methods disclosed in the several method embodiments provided in this disclosure can be arbitrarily combined without conflict to obtain new method embodiments.

[0170] The features disclosed in the several product embodiments provided in this disclosure can be combined arbitrarily without conflict to obtain new product embodiments.

[0171] The features disclosed in the several method or device embodiments provided in this disclosure can be arbitrarily combined without conflict to obtain new method or device embodiments.

[0172] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this disclosure. Therefore, "in one embodiment" or "in some embodiments" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this disclosure, the sequence numbers of the above-described processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this disclosure. The sequence numbers of the above-described embodiments are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0173] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0174] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A splicing filter, characterized in that, include: A first type of filter and a second type of filter concatenated with the first type of filter; the first type of filter processes the input signal and outputs it to the second type of filter; The splicing filter is a multi-order super-Gaussian filter; Both the first type of filter and the second type of filter include at least one filter; The filtering frequency response function of the splicing filter is the product of the filtering frequency response function of at least one of the first type of filters and the filtering frequency response function of at least one of the second type of filters; At least one of the filters of the first type is cascaded with at least one of the filters of the second type to form a multi-stage cascaded structure; In the multi-stage cascaded structure, the order of the filter frequency response function corresponding to the first stage filter is M, and the order of the filter frequency response function corresponding to the next stage filter in the multi-stage cascaded structure is N; the next stage filter is a filter cascaded after the first stage filter. Where M and N are positive numbers, and M is greater than the order of the splicing filter, while N is less than the order of the splicing filter.

2. The splicing filter according to claim 1, characterized in that, At least one of the filters includes at least one Michelson interferometer; or, At least one of the filters comprises at least one arrayed waveguide grating; or, At least one of the filters includes a Michelson interferometer and an arrayed waveguide grating, the arrayed waveguide grating being cascaded with the Michelson interferometer.

3. The splicing filter according to claim 2, characterized in that, The filter includes a Michelson interferometer; the first specification parameter of the splicing filter is determined by the Michelson interferometer; wherein the first specification parameter includes: center wavelength accuracy, bandwidth and / or adjacent isolation.

4. The splicing filter according to claim 2, characterized in that, The filter includes an arrayed waveguide grating; the second index parameter of the spliced ​​filter is determined by the arrayed waveguide grating; wherein the second index parameter includes: non-adjacent isolation.

5. The splicing filter according to any one of claims 1 to 4, characterized in that, The splicing filter is a third-order super-Gaussian filter.

6. The splicing filter according to any one of claims 1 to 4, characterized in that, The insertion loss value of the signal in the splicing filter is the sum of the insertion loss value of the signal in the first type of filter and the insertion loss value of the signal in the second type of filter.

7. A splicing method, characterized in that, include: Obtain the first type filter and the second type filter; By splicing the first type of filter and the second type of filter, a spliced ​​filter is obtained; The splicing filter is a multi-order super-Gaussian filter; Both the first type of filter and the second type of filter include at least one filter; The filtering frequency response function of the splicing filter is the product of the filtering frequency response function of at least one of the first type of filters and the filtering frequency response function of at least one of the second type of filters; At least one of the filters of the first type is cascaded with at least one of the filters of the second type to form a multi-stage cascaded structure; In the multi-stage cascaded structure, the order of the filter frequency response function corresponding to the first stage filter is M, and the order of the filter frequency response function corresponding to the next stage filter in the multi-stage cascaded structure is N; the next stage filter is a filter cascaded after the first stage filter. Where M and N are positive numbers, and M is greater than the order of the splicing filter, while N is less than the order of the splicing filter.

8. The method according to claim 7, characterized in that, Both the first type of filter and the second type of filter include at least one filter; At least one of the filters includes at least one Michelson interferometer; or, At least one of the filters comprises at least one arrayed waveguide grating; or, At least one of the filters includes a Michelson interferometer and an arrayed waveguide grating, the arrayed waveguide grating being cascaded with the Michelson interferometer.

9. The method according to claim 8, characterized in that, The first parameter of the splicing filter is determined by the Michelson interferometer; the second parameter of the splicing filter is determined by the arrayed waveguide grating. The first indicator parameter includes: center wavelength accuracy, bandwidth and / or adjacent isolation; the second indicator parameter includes: non-adjacent isolation.

10. An electronic device, characterized in that, Includes the splicing filter as described in any one of claims 1 to 6.

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