Wavelength division demultiplexing chip with balanced array power

Abstract

The invention provides a wavelength division demultiplexing chip with balanced array power. The wavelength division demultiplexing chip comprises a substrate; the input optical waveguide is formed on the substrate, and the input optical waveguide is suitable for inputting an optical signal which is to be processed and comprises a plurality of wavelengths; the Mach-Zehnder interference module is formed on the substrate, and the Mach-Zehnder interference module is suitable for enabling optical signals containing a plurality of wavelengths to generate interference so as to be respectively output from the plurality of output optical waveguides of the Mach-Zehnder interference module; the modulation array module is formed on the substrate and comprises a plurality of groups of symmetrical modulation arms; a plurality of modulation waveguides and a plurality of heating electrodes arranged on the modulation waveguides at intervals, the plurality of modulation waveguides are respectively connected with the plurality of groups of symmetrical modulation arms, and by applying voltage to the heating electrodes, the output power of the optical signals with different wavelengths is changed by utilizing a thermo-optic effect, so that the power of the optical signals with different wavelengths is balanced; and the plurality of transmission electrodes are electrically connected with the plurality of heating electrodes respectively so as to transmit external voltage to the heating electrodes.

Description

Technical Field

[0001] The present disclosure relates to the technical field of micro-nano optoelectronics integration, and more specifically, to a wavelength division multiplexing chip with array power balance. Background Art

[0002] In order to meet the needs of high-speed and large-capacity optical communication systems, wavelength division multiplexing technology came into being. The advantages of wavelength division multiplexing technology, such as large capacity, high compatibility and low cost, are widely used in optical communication systems and all-optical networks. Among them, wavelength division multiplexing chips, as a component of wavelength division multiplexing technology, will affect the overall performance of communication.

[0003] At present, in order to achieve multifunctional processing of optical signals, it is necessary to connect multiple independent discrete devices. However, discrete devices connected by optical fiber are bulky, and the direct connection end face coupling of multiple device chips not only increases coupling loss, but also affects the stability of the connection, reducing the reliability of the chip and each discrete device. Summary of the invention

[0004] In order to solve at least one of the technical problems in the prior art, the present disclosure provides a wavelength division multiplexing chip with array power balance, which can avoid the problem of increased coupling loss of multiple chips when discrete devices are connected.

[0005] The embodiment of the present disclosure provides a wavelength division multiplexing chip with balanced array power, comprising: a substrate; an input optical waveguide formed on the substrate, the input optical waveguide being suitable for inputting an optical signal containing multiple wavelengths to be processed; a Mach-Zehnder interference module formed on the substrate, the Mach-Zehnder interference module being suitable for causing the optical signal containing multiple wavelengths to interfere so as to be outputted from multiple output optical waveguides of the Mach-Zehnder interference module respectively; and a modulation array module formed on the substrate, the modulation array module comprising: multiple groups of symmetrical modulation arms being suitable for respectively receiving optical signals of different wavelengths from multiple output optical waveguides of the Mach-Zehnder interference module; multiple modulation waveguides and multiple heating electrodes arranged at intervals on the modulation waveguides, the multiple modulation waveguides being respectively connected to the multiple groups of symmetrical modulation arms, applying voltage to the heating electrodes, and using thermo-optical effect to change the output power of optical signals of different wavelengths so as to balance the power of optical signals of each wavelength; and multiple transmission electrodes being respectively electrically connected to the multiple heating electrodes so as to transmit external voltage to the heating electrodes.

[0006] According to some embodiments of the present disclosure, the Mach-Zehnder interference module is a cascade of multiple-stage Mach-Zehnder interference units to increase the bandwidth of the optical signal.

[0007] According to some embodiments of the present disclosure, the above-mentioned Mach-Zehnder interference module includes a first Mach-Zehnder interference unit, and the above-mentioned first Mach-Zehnder interference unit includes: a first coupling waveguide; a first asymmetric extension arm, suitable for changing the phase difference of the above-mentioned optical signal containing multiple wavelengths as a delay line; a first directional coupling waveguide, suitable for power distribution of the optical signal after the phase difference is changed; and an interference unit, and the above-mentioned interference unit allows optical signals of different wavelengths to interfere with each other at different phase differences, thereby being output from the first output optical waveguide and the second output optical waveguide of the above-mentioned first Mach-Zehnder interference unit respectively.

[0008] According to some embodiments of the present disclosure, the above-mentioned interference unit includes a first sub-interference unit and a second sub-interference unit connected in sequence, and the above-mentioned first sub-interference unit and the above-mentioned second sub-interference unit respectively include: a second asymmetric extension arm, suitable for serving as a delay line to change the phase difference of the optical signal after power distribution; a second directional coupling waveguide, suitable for power distribution of the optical signal output by the above-mentioned second asymmetric extension arm.

[0009] According to some embodiments of the present disclosure, the delay line length of the second asymmetric extension arm is twice the delay line length of the first asymmetric extension arm, and the protruding direction of the second asymmetric extension arm is opposite to the protruding direction of the first asymmetric extension arm.

[0010] According to some embodiments of the present disclosure, the Mach-Zehnder interference module further includes two second Mach-Zehnder interference units, the input ports of the two second Mach-Zehnder interference units are respectively connected to the first output optical waveguide and the second output optical waveguide of the first Mach-Zehnder interference unit, and the second Mach-Zehnder interference unit includes a second coupling waveguide, a third asymmetric extension arm, a third directional coupling waveguide, a fourth asymmetric extension arm and a fourth directional coupling waveguide connected in sequence.

[0011] According to some embodiments of the present disclosure, the delay line length of the first asymmetric extension arm is twice the delay line length of the third asymmetric extension arm, and the protruding direction of the first asymmetric extension arm is the same as the protruding direction of the third asymmetric extension arm, the delay line length of the first asymmetric extension arm is the same as the delay line length of the fourth asymmetric extension arm, and the protruding direction of the first asymmetric extension arm is opposite to the protruding direction of the fourth asymmetric extension arm.

[0012] According to some embodiments of the present disclosure, the Mach-Zehnder interference module further includes a plurality of third Mach-Zehnder interference units, the input ports of the third Mach-Zehnder interference units are respectively connected to the plurality of output optical waveguides of the second Mach-Zehnder interference units, the third Mach-Zehnder interference units include a third coupling waveguide, a fifth asymmetric extension arm and a fourth coupling waveguide connected in sequence, wherein the delay line length of the first asymmetric extension arm is four times the delay line length of the fifth asymmetric extension arm, and the protruding direction of the first asymmetric extension arm is the same as the protruding direction of the fifth asymmetric extension arm.

[0013] According to some embodiments of the present disclosure, the heating electrode is formed on the modulation waveguide by deposition.

[0014] According to a wavelength division multiplexing chip with array power balance provided by the present disclosure, an input optical waveguide formed on a substrate is used to input an optical signal containing multiple wavelengths to be processed, and a Mach-Zehnder interference module formed on the substrate is used to make the optical signal containing multiple wavelengths interfere so that the optical signals are output from multiple output optical waveguides of the Mach-Zehnder interference module respectively. The modulation array module formed on the substrate includes multiple groups of symmetrical modulation arms, multiple modulation waveguides, multiple heating electrodes and multiple transmission electrodes arranged on the modulation waveguides at intervals. The multiple modulation waveguides are respectively connected to the multiple groups of symmetrical modulation arms. By applying voltage to the heating electrodes, the output power of optical signals of different wavelengths is changed by using the thermo-optical effect so that the power of optical signals of each wavelength is balanced. The transmission electrodes electrically connected to the multiple heating electrodes are used to transmit the external voltage to the heating electrodes. The Mach-Zehnder interference module and the modulation array module can be integrated on the substrate at the same time, so that the optical signals containing multiple wavelengths interfere so that the optical signals are output from multiple output optical waveguides of the Mach-Zehnder interference module respectively, and the power of optical signals of each wavelength is balanced, thereby avoiding the problem of increased coupling loss of multiple chips when discrete devices are connected. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a stereoscopic diagram of a wavelength division multiplexing chip for array power balancing according to an exemplary embodiment of the present disclosure;

[0016] Figure 2 is a cross-sectional view of a Mach-Zehnder interferometer module according to an exemplary embodiment of the present disclosure;

[0017] Figure 3 is a cross-sectional view of a modulation array module according to an exemplary embodiment of the present disclosure;

[0018] Figure 4 is a spectrum output simulation diagram of a wavelength division multiplexing chip with array power equalization according to an exemplary embodiment of the present disclosure; and

[0019] Figure 5 This is a modulation simulation diagram of a wavelength division multiplexing chip with array power balance after multiple channels are modulated by a modulation array module at the same time according to an illustrative embodiment of the present disclosure.

[0020] In the drawings, the meanings of the reference numerals are as follows:

[0021] 1. Substrate;

[0022] 2. Input optical waveguide;

[0023] 3. Waveguide core area;

[0024] 4. Rectangular waveguide;

[0025] 5. A first coupled waveguide;

[0026] 6. The first asymmetric extension arm;

[0027] 7. A first directional coupling waveguide;

[0028] 8. A first sub-interference unit;

[0029] 9. A second sub-interference unit;

[0030] 10. Second asymmetric extension arm;

[0031] 11. A second directional coupling waveguide;

[0032] 12. A second coupling waveguide;

[0033] 13. The third asymmetric extension arm;

[0034] 14. The third directional coupling waveguide;

[0035] 15. Fourth asymmetric extension arm;

[0036] 16. A fourth directional coupling waveguide;

[0037] 17. A third coupling waveguide;

[0038] 18. Fifth asymmetric extension arm;

[0039] 19. A fourth coupled waveguide;

[0040] 20. Symmetrical modulation arm;

[0041] 21. Modulation waveguide;

[0042] 22. Heating electrode;

[0043] 23. Transmission electrode. DETAILED DESCRIPTION

[0044] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0045] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0046] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0047] When using expressions such as "at least one of A, B, and C, etc.", it should generally be interpreted as the meaning of the expression generally understood by those skilled in the art. For example, "a system having at least one of A, B, and C" should include but not be limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc. When using expressions such as "at least one of A, B, or C, etc.", it should generally be interpreted as the meaning of the expression generally understood by those skilled in the art. For example, "a system having at least one of A, B, or C" should include but not be limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.

[0048] In order to meet the needs of high-speed and large-capacity optical communication systems, wavelength division multiplexing technology came into being. The advantages of wavelength division multiplexing technology, such as large capacity, high compatibility and low cost, are widely used in optical communication systems and all-optical networks. Among them, wavelength division multiplexing chips, as components of wavelength division multiplexing technology, will affect the overall performance of communication. Wavelength division multiplexing chips are usually arrayed waveguide grating structures, but the output spectrum shape of the arrayed waveguide grating structure is Gaussian, which limits the channel bandwidth to a certain extent, and the insertion loss of the arrayed waveguide grating structure is large, usually around 4dB. Although the wavelength division multiplexing chip can meet the needs of large-bandwidth flat-top spectrum output when it is a micro-ring structure, the micro-ring structure is very sensitive to the temperature of the process, so it has more stringent requirements on the processing technology and the use environment. In order to achieve multi-functional processing of optical signals, it is necessary to connect multiple independent discrete devices. However, the discrete devices connected by optical fiber are bulky, and the direct connection end face coupling of the chips of multiple devices not only increases the coupling loss, but also is affected by the fixed stability of the connection, reducing the reliability of the chip and each discrete device. According to the concept of one aspect of the present disclosure, the present disclosure integrates a Mach-Zehnder interference module and a modulation array module on a substrate at the same time, so that optical signals containing multiple wavelengths interfere with each other and are output from multiple output optical waveguides of the Mach-Zehnder interference module respectively. At the same time, the power balance of optical signals of each wavelength is achieved through the modulation array module, thereby avoiding the problem of increased coupling loss of multiple chips when discrete devices are connected.

[0049] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0050] Figure 1 is a stereoscopic diagram of a wavelength division multiplexing chip for array power balancing according to an illustrative embodiment of the present disclosure.

[0051] According to the embodiment of the present disclosure, a wavelength division multiplexing chip for array power balancing is provided, such as Figure 1As shown, the wavelength division multiplexing chip with array power balance includes a substrate 1, an input optical waveguide 2, a Mach-Zehnder interference module and a modulation array module. The input optical waveguide 2 is formed on the substrate 1, and the input optical waveguide 2 is suitable for inputting an optical signal containing multiple wavelengths to be processed. The Mach-Zehnder interference module is formed on the substrate 1, and the Mach-Zehnder interference module is suitable for causing the optical signals containing multiple wavelengths to interfere so as to be outputted from multiple output optical waveguides of the Mach-Zehnder interference module respectively. The modulation array module is formed on the substrate 1, and the modulation array module includes multiple groups of symmetrical modulation arms 20, multiple modulation waveguides 21, multiple heating electrodes 22 and multiple transmission electrodes 23 arranged at intervals on the modulation waveguide 21. The multiple groups of symmetrical modulation arms 20 are suitable for respectively receiving optical signals of different wavelengths from multiple output optical waveguides of the Mach-Zehnder interference module. The multiple modulation waveguides 21 are respectively connected to the multiple groups of symmetrical modulation arms 20, and by applying voltage to the heating electrode 22, the output power of optical signals of different wavelengths is changed by using the thermo-optical effect, so that the power of optical signals of each wavelength is balanced. The plurality of transmission electrodes 23 are electrically connected to the plurality of heating electrodes 22 , respectively, to transmit an external voltage to the heating electrodes 22 .

[0052] Figure 2 is a cross-sectional view of a Mach-Zehnder interferometer module according to an exemplary embodiment of the present disclosure.

[0053] According to an optional embodiment of the present disclosure, Figure 2 As shown, the material used for the substrate 1 is silicon, and the waveguide core region 3 (the input optical waveguide 2 and the Mach-Zehnder interference module are both located in the waveguide core region 3) is located on the upper side of the substrate 1. The material used for the waveguide core region 3 is germanium-doped silicon dioxide. The optical signal is transmitted at the rectangular waveguide 4 in the waveguide core region 3. The size of the rectangular waveguide 4 is 4μm×4μm to ensure the single-mode transmission of the optical signal. The lower side of the rectangular waveguide 4 is the lower cladding, the material of the lower cladding is silicon dioxide, and the thickness of the lower cladding is greater than 20μm to ensure that the optical signal will not leak to the substrate 1 during transmission. The upper side of the rectangular waveguide 4 is the upper cladding, and the material of the upper cladding is air, silicon dioxide or other semiconductor materials with a refractive index lower than that of the rectangular waveguide 4. The thickness of the upper cladding is 15μm.

[0054] According to an embodiment of the present disclosure, the heating electrode 22 is formed on the modulation waveguide 21 by deposition.

[0055] Figure 3 is a cross-sectional view of a modulation array module according to an exemplary embodiment of the present disclosure.

[0056] According to an optional embodiment of the present disclosure, Figure 3As shown, the material used for the substrate 1 is silicon, and the waveguide core region 3 (the modulation array module is located in the waveguide core region 3) is located on the upper side of the substrate 1. The material used for the waveguide core region 3 is germanium-doped silicon dioxide. The optical signal is transmitted at the rectangular waveguide 4 in the waveguide core region 3. The size of the rectangular waveguide 4 is 4μm×4μm to ensure the single-mode transmission of the optical signal. The lower side of the rectangular waveguide 4 is the lower cladding, the material of the lower cladding is silicon dioxide, and the thickness of the lower cladding is greater than 20μm to ensure that the optical signal will not leak to the substrate 1 during transmission. The upper side of the rectangular waveguide 4 is the upper cladding, and the material of the upper cladding is air, silicon dioxide or other semiconductor materials with a refractive index lower than that of the rectangular waveguide 4. The thickness of the upper cladding is 15μm. In order to achieve the regulation of the refractive index of the waveguide core area 3 by temperature, the external voltage is transmitted to the heating electrode 22 through the transmission electrode 23. The material of the transmission electrode 23 is, for example, Au or Cr. The heating electrodes 22 of metal material are deposited at intervals above the single modulation waveguide 21. The material of the heating electrode 22 is, for example, Ti or Wu.

[0057] According to the embodiments of the present disclosure, the Mach-Zehnder interferometer module and the modulation array module will not cause process incompatibility problems due to excessive structural differences under the same process flow.

[0058] According to an embodiment of the present disclosure, the wavelength division multiplexing chip with balanced array power uses an input optical waveguide 2 formed on a substrate 1 to input an optical signal containing multiple wavelengths to be processed, and uses a Mach-Zehnder interference module formed on the substrate 1 to make the optical signal containing multiple wavelengths interfere so as to be output from multiple output optical waveguides of the Mach-Zehnder interference module respectively. The modulation array module formed on the substrate 1 includes multiple groups of symmetrical modulation arms 20, multiple modulation waveguides 21, multiple heating electrodes 22 and multiple transmission electrodes 23 arranged on the modulation waveguide 21 at intervals. The multiple groups of symmetrical modulation arms 20 are suitable for respectively receiving optical signals of different wavelengths from multiple output optical waveguides of the Mach-Zehnder interference module, and the multiple modulation waveguides 21 are respectively connected to the multiple groups of symmetrical modulation arms 20. 0 connection, by applying voltage to the heating electrode 22, the output power of the optical signal of different wavelengths is changed by using the thermo-optical effect, so that the power of the optical signal of each wavelength is balanced, and the transmission electrode 23 electrically connected to the plurality of heating electrodes 22 is used to transmit the external voltage to the heating electrode 22, so that the Mach-Zehnder interference module and the modulation array module can be integrated on the substrate 1 at the same time, so that the optical signals containing multiple wavelengths interfere with each other and are output from the plurality of output optical waveguides of the Mach-Zehnder interference module respectively, while the power of the optical signal of each wavelength is balanced, the problem of increased coupling loss of multiple chips when discrete devices are connected is avoided, the volume is reduced, and the performance stability of the wavelength division multiplexing chip with array power balance is improved while performing multi-functional processing on the optical signal.

[0059] According to an embodiment of the present disclosure, the Mach-Zehnder interference module is a cascade of multiple-stage Mach-Zehnder interference units to increase the bandwidth of the optical signal.

[0060] According to an embodiment of the present disclosure, the Mach-Zehnder interference module is a cascade of multi-stage Mach-Zehnder interference units. A single beam of optical signals to be processed containing multiple wavelengths input by the input optical waveguide 2 is decomposed into multiple beams with different wavelengths, for example, 4 beams or 8 beams, after being cascaded through the multi-stage Mach-Zehnder interference units, and are output from multiple output optical waveguides of the Mach-Zehnder interference module respectively.

[0061] According to the embodiments of the present disclosure, the expansion of wavelength division multiplexing channels and a more flat-topped spectrum output can be achieved by cascading multiple stages of Mach-Zehnder interferometer units.

[0062] According to an embodiment of the present disclosure, the Mach-Zehnder interference module includes a first Mach-Zehnder interference unit, and the first Mach-Zehnder interference unit includes a first coupling waveguide 5, a first asymmetric extension arm 6, a first directional coupling waveguide 7 and an interference unit. The first asymmetric extension arm 6 is suitable for changing the phase difference of an optical signal containing multiple wavelengths as a delay line. The first directional coupling waveguide 7 is suitable for power distribution of the optical signal after the phase difference is changed. The interference unit is configured to output from the first output optical waveguide and the second output optical waveguide of the first Mach-Zehnder interference unit respectively through mutual interference of optical signals of different wavelengths at different phase differences.

[0063] According to an embodiment of the present disclosure, the lengths of the coupling regions of the first coupling waveguide 5 and the first directional coupling waveguide 7 are different, so that the amount of evanescent wave coupling of the optical signal from one waveguide to another waveguide in the coupling region is different, that is, the coupling ratio is different. The first coupling waveguide 5 is a 3dB coupling waveguide, the coupling ratio of the first coupling waveguide 5 is 0.5, and the coupling ratio of the first directional coupling waveguide 7 is 0.2.

[0064] According to an embodiment of the present disclosure, the first coupling waveguide 5 is suitable for performing power distribution on the optical signal input by the input optical waveguide 2, and then passes through the first asymmetric extension arm 6, the first asymmetric extension arm 6 is suitable for changing the phase difference of the optical signal containing multiple wavelengths as a delay line, and then passes through the first directional coupling waveguide 7, the first directional coupling waveguide 7 is suitable for performing power distribution on the optical signal after the phase difference is changed again, and coupling interference is performed on the optical signal containing multiple wavelengths, and the optical signals of different wavelengths are enhanced or offset by interference at different phase differences, and then pass through the interference unit, and the interference unit again interferes with each other at different phase differences through the optical signals of different wavelengths. At this time, the single optical signal is decomposed into two optical signals after passing through the first Mach-Zehnder interference unit, and is output from the first output optical waveguide and the second output optical waveguide of the first Mach-Zehnder interference unit, respectively, to realize wavelength division multiplexing, and the two output optical waveguides respectively output spectral peaks of 4 channels, that is, the first output optical waveguide outputs spectral peaks of channels 1, 3, 5, and 7, and the second output optical waveguide outputs spectral peaks of channels 2, 4, 6, and 8.

[0065] According to an embodiment of the present disclosure, the interference unit includes a first sub-interference unit 8 and a second sub-interference unit 9 connected in sequence, and the first sub-interference unit 8 and the second sub-interference unit 9 respectively include a second asymmetric extension arm 10 and a second directional coupling waveguide 11. The second asymmetric extension arm 10 is suitable for changing the phase difference of the optical signal after power distribution as a delay line. The second directional coupling waveguide 11 is suitable for power distribution of the optical signal output by the second asymmetric extension arm 10.

[0066] According to an embodiment of the present disclosure, the coupling ratio of the second directional coupling waveguide 11 of the first sub-interference unit 8 is 0.2, and the coupling ratio of the second directional coupling waveguide 11 of the second sub-interference unit 9 is 0.04. The optical signal output by the first directional coupling waveguide 7 first passes through the second asymmetric extension arm 10 and the second directional coupling waveguide 11 of the first sub-interference unit 8, and then passes through the second asymmetric extension arm 10 and the second directional coupling waveguide 11 of the second sub-interference unit 9, and is finally output from the first output optical waveguide and the second output optical waveguide of the first Mach-Zehnder interference unit respectively.

[0067] According to an embodiment of the present disclosure, the first Mach-Zehnder interferometer unit includes multiple asymmetric extension arms (a first asymmetric extension arm 6 and a second asymmetric extension arm 10), which can reduce signal crosstalk between multiple channels and make the top of the output waveform flatter, further improving the bandwidth of the channel.

[0068] According to an embodiment of the present disclosure, the delay line length of the second asymmetric extension arm 10 is twice the delay line length of the first asymmetric extension arm 6 , and the protruding direction of the second asymmetric extension arm 10 is opposite to the protruding direction of the first asymmetric extension arm 6 .

[0069] According to an embodiment of the present disclosure, the delay line length L1 of the first asymmetric extension arm 6 can be calculated by the following formula (1):

[0070]

[0071] Where λ is the central wavelength, n group is the group refractive index of the rectangular waveguide 4 of germanium-doped silicon dioxide, and Δλ is the wavelength division multiplexing channel spacing.

[0072] According to the embodiment of the present disclosure, the delay line length of the second asymmetric extension arm 10 is twice the delay line length of the first asymmetric extension arm 6. If there is an error in the delay line, it will cause the output spectrum waveform to collapse or even fail to output the spectrum. The delay line length L2 of the second asymmetric extension arm 10 can be expressed by the following formula (2):

[0073] L2=2L1 (2).

[0074] According to an embodiment of the present disclosure, the protrusion direction of the second asymmetric extension arm 10 is opposite to the protrusion direction of the first asymmetric extension arm 6, and the protrusion direction of the asymmetric extension arm is divided into a waveguide upper arm protrusion and a waveguide lower arm protrusion. The asymmetric extension arm changes the phase difference of the optical signal by adjusting the optical path difference of the optical signal in the two waveguides. The first asymmetric extension arm 6 is a waveguide upper arm protrusion, which is suitable for changing the waveguide optical path difference of the waveguide upper arm, thereby changing the phase difference of the optical signal. The second asymmetric extension arm 10 is a waveguide lower arm protrusion, which is suitable for changing the waveguide optical path difference of the waveguide lower arm, thereby changing the phase difference of the optical signal.

[0075] According to an embodiment of the present disclosure, the Mach-Zehnder interference module also includes two second Mach-Zehnder interference units, the input ports of the two second Mach-Zehnder interference units are respectively connected to the first output optical waveguide and the second output optical waveguide of the first Mach-Zehnder interference unit, and the second Mach-Zehnder interference unit includes a second coupling waveguide 12, a third asymmetric extension arm 13, a third directional coupling waveguide 14, a fourth asymmetric extension arm 15 and a fourth directional coupling waveguide 16 connected in sequence.

[0076] According to an embodiment of the present disclosure, the second coupling waveguide 12 is a 3dB coupling waveguide, the coupling ratio of the second coupling waveguide 12 is 0.5, the coupling ratio of the third directional coupling waveguide 14 is 0.29, and the coupling ratio of the fourth directional coupling waveguide 16 is 0.08.

[0077] According to an embodiment of the present disclosure, two optical signals outputted from the first output optical waveguide and the second output optical waveguide of the first Mach-Zehnder interference unit enter two second Mach-Zehnder interference units respectively. Taking the second Mach-Zehnder interference unit connected to the first output optical waveguide as an example, the optical signal first passes through the second coupling waveguide 12, which is suitable for performing power distribution on the optical signal outputted from the first Mach-Zehnder interference unit, and then passes through the third asymmetric extension arm 13, which is suitable for changing the phase difference of the optical signal as a delay line, and then passes through the third directional coupling waveguide 14, which is suitable for performing power distribution on the optical signal outputted from the third asymmetric extension arm 13 again, and then passes through the fourth asymmetric extension arm 15, which is suitable for changing the optical signal as a delay line again. The phase difference of the signal finally passes through the fourth directional coupling waveguide 16. The fourth directional coupling waveguide 16 is suitable for performing power distribution on the optical signal output by the fourth asymmetric extension arm 15 again. At this time, the spectral peaks of the four channels respectively output by the first output optical waveguide and the second output optical waveguide of the first Mach-Zehnder interference unit, that is, the first output optical waveguide outputs the spectral peaks of channels 1, 3, 5, and 7, and the second output optical waveguide outputs the spectral peaks of channels 2, 4, 6, and 8. After passing through the second Mach-Zehnder interference unit, the spectral peaks of the four channels are respectively output from the third output optical waveguide and the fourth output optical waveguide of the second Mach-Zehnder interference unit to realize wavelength division multiplexing. The two output optical waveguides respectively output the spectral peaks of two channels, that is, the third output optical waveguide outputs the spectral peaks of channels 3 and 7, and the fourth output optical waveguide outputs the spectral peaks of channels 1 and 5. At the same time, after passing through the second Mach-Zehnder interference unit connected to the second output optical waveguide, the spectral peaks of the four channels are output from the fifth output optical waveguide and the sixth output optical waveguide of the second Mach-Zehnder interference unit respectively to realize wavelength division multiplexing, and the two output optical waveguides output the spectral peaks of two channels respectively, that is, the fifth output optical waveguide outputs the spectral peaks of channels 2 and 6, and the sixth output optical waveguide outputs the spectral peaks of channels 4 and 8.

[0078] According to an embodiment of the present disclosure, the delay line length of the first asymmetric extension arm 6 is twice the delay line length of the third asymmetric extension arm 13, and the protruding direction of the first asymmetric extension arm 6 is the same as the protruding direction of the third asymmetric extension arm 13. The delay line length of the first asymmetric extension arm 6 is the same as the delay line length of the fourth asymmetric extension arm 15, and the protruding direction of the first asymmetric extension arm 6 is opposite to the protruding direction of the fourth asymmetric extension arm 15.

[0079] According to an embodiment of the present disclosure, the delay line length L3 of the third asymmetric extension arm 13 can be expressed by the following formula (3):

[0080]

[0081] According to an embodiment of the present disclosure, the third asymmetric extension arm 13 is a waveguide upper arm protrusion.

[0082] According to an embodiment of the present disclosure, the delay line length L4 of the fourth asymmetric extension arm 15 can be expressed by the following formula (4):

[0083] L4=L1 (4).

[0084] According to an embodiment of the present disclosure, the fourth asymmetric extension arm 15 is a waveguide lower arm protrusion.

[0085] According to an embodiment of the present disclosure, the Mach-Zehnder interference module further includes a plurality of third Mach-Zehnder interference units, the input ports of the third Mach-Zehnder interference units are respectively connected to a plurality of output optical waveguides of the second Mach-Zehnder interference units, and the third Mach-Zehnder interference unit includes a third coupling waveguide 17, a fifth asymmetric extension arm 18, and a fourth coupling waveguide 19 connected in sequence. The delay line length of the first asymmetric extension arm 6 is four times the delay line length of the fifth asymmetric extension arm 18, and the protruding direction of the first asymmetric extension arm 6 is the same as the protruding direction of the fifth asymmetric extension arm 18.

[0086] According to an embodiment of the present disclosure, the input ports of the plurality of third Mach-Zehnder interference units are respectively connected to the third output optical waveguide, the fourth output optical waveguide, the fifth output optical waveguide and the sixth output optical waveguide of the second Mach-Zehnder interference unit. The third coupling waveguide 17 is a 3dB coupling waveguide, and the coupling ratio of the third coupling waveguide 17 is 0.5. The fourth coupling waveguide 19 is a 3dB coupling waveguide, and the coupling ratio of the fourth coupling waveguide 19 is 0.5. At this time, the four output optical waveguides of the second Mach-Zehnder interference unit, each output optical waveguide outputs 2 channel spectral peaks. After passing through the third Mach-Zehnder interference unit, the spectral peaks of the 2 channels are respectively output from the seventh output optical waveguide and the eighth output optical waveguide of each third Mach-Zehnder interference unit to achieve wavelength division multiplexing, that is, each channel spectral peak is output from 8 output optical waveguides.

[0087] According to an embodiment of the present disclosure, the delay line length L5 of the fifth asymmetric extension arm 18 can be expressed by the following formula (5):

[0088]

[0089] According to an embodiment of the present disclosure, the fifth asymmetric extension arm 18 is a waveguide upper arm protrusion.

[0090] According to an embodiment of the present disclosure, the optical signals output by the eight output optical waveguides enter the symmetrical modulation arm 20 of the modulation array module, and enter the modulation waveguide 21 after passing through the 3dB coupling waveguide respectively. The coupling ratio of the 3dB coupling waveguide is 0.5. By applying voltage to the multiple heating electrodes 22 arranged at intervals on the modulation waveguide 21, the output power of optical signals of different wavelengths is changed by utilizing the thermo-optical effect, so that the power of optical signals of each wavelength is balanced, and then output after passing through the 3dB coupling waveguide.

[0091] According to the embodiment of the present disclosure, the coupling waveguide intervals are all maintained at 1 μm.

[0092] According to the embodiments of the present disclosure, the Mach-Zehnder interferometer module and the modulation array module are integrated on the substrate 1 at the same time, which reduces the volume of the wavelength division multiplexing chip with array power balance and reduces the coupling loss.

[0093] Figure 4 It is a spectrum output simulation diagram of a wavelength division multiplexing chip with array power balance according to an illustrative embodiment of the present disclosure.

[0094] According to the embodiments of the present disclosure, Figure 4 As shown, Figure 4 To simulate the spectral output of 8 channels without modulation, it can be seen from the spectral simulation results that the cascade of multi-stage Mach-Zehnder interferometer units can effectively realize the output of a large-bandwidth flat-top waveform, and the insertion loss of the 8 channels is less than 0.1dB, ensuring the good consistency of the insertion loss of each channel.

[0095] Figure 5 This is a modulation simulation diagram of a wavelength division multiplexing chip with array power balance after multiple channels are modulated by a modulation array module at the same time according to an illustrative embodiment of the present disclosure.

[0096] According to the embodiments of the present disclosure, Figure 5 As shown, channel 1, channel 3, channel 4 and channel 6 are thermally modulated at the same time. It can be seen from the simulation results that the modulation depth of the four modulated channels can reach at least -25dB. By applying voltage to the heating electrodes 22 corresponding to different output channels, multiple channels can be modulated at the same time.

[0097] It should also be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only reference directions of the drawings and are not intended to limit the scope of protection of the present disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or configurations will be omitted when they may cause confusion in the understanding of the present disclosure, and the shapes and sizes of the components in the drawings do not reflect the actual size and proportion, but only illustrate the contents of the embodiments of the present disclosure.

[0098] Unless otherwise indicated, the numerical parameters in this specification and the appended claims are approximate values ​​and can vary according to the desired properties obtained through the content of the present disclosure. Specifically, all numbers used in the specification and claims to express the content of the composition, reaction conditions, etc., should be understood to be modified by the term "about" in all cases. In general, the meaning of the expression is to include a variation of ±10% in some embodiments, ±5% in some embodiments, ±1% in some embodiments, and ±0.5% in some embodiments by a specific number.

[0099] The ordinal numbers used in the specification and claims, such as "first", "second", "third", etc., to modify the corresponding elements, do not themselves mean that the elements have any ordinal numbers, nor do they represent the order of one element and another element, or the order in the manufacturing method. The use of these ordinal numbers is only used to clearly distinguish a component with a certain name from another component with the same name.

[0100] In addition, unless the steps are specifically described or must occur in sequence, the order of the above steps is not limited to the above list, and can be changed or rearranged according to the required design. And the above embodiments can be mixed and matched with each other or with other embodiments based on design and reliability considerations, that is, the technical features in different embodiments can be freely combined to form more embodiments.

[0101] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. The scope of the present disclosure is defined by the attached claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A wavelength division multiplexing chip with array power balance, comprising: substrate; An input optical waveguide, formed on the substrate, the input optical waveguide being suitable for inputting an optical signal containing multiple wavelengths to be processed; A Mach-Zehnder interference module, formed on the substrate, the Mach-Zehnder interference module is suitable for causing the optical signal containing multiple wavelengths to interfere so as to be outputted from multiple output optical waveguides of the Mach-Zehnder interference module respectively; as well as A modulation array module is formed on the substrate, and the modulation array module includes: A plurality of groups of symmetrical modulation arms, adapted to respectively receive optical signals of different wavelengths from a plurality of output optical waveguides of the Mach-Zehnder interferometer module; a plurality of modulation waveguides and a plurality of heating electrodes arranged at intervals on the modulation waveguides, the plurality of modulation waveguides are respectively connected to the plurality of groups of symmetrical modulation arms, and the output power of optical signals of different wavelengths is changed by applying voltage to the heating electrodes using thermo-optical effect, so that the power of optical signals of various wavelengths is balanced; and A plurality of transmission electrodes are electrically connected to the plurality of heating electrodes respectively to transmit an external voltage to the heating electrodes.

2. The array power balanced wavelength division multiplexing chip according to claim 1, wherein: The Mach-Zehnder interference module is a cascade of multiple Mach-Zehnder interference units to increase the bandwidth of the optical signal.

3. The array power balanced wavelength division multiplexing chip according to claim 1, wherein: The Mach-Zehnder interferometer module includes a first Mach-Zehnder interferometer unit, and the first Mach-Zehnder interferometer unit includes: a first coupled waveguide; A first asymmetric extension arm, adapted to act as a delay line to change the phase difference of the optical signal comprising multiple wavelengths; The first directional coupling waveguide is suitable for performing power distribution on the optical signal after the phase difference is changed; An interference unit, wherein the interference unit causes light signals of different wavelengths to interfere with each other at different phase differences, so as to be output from the first output optical waveguide and the second output optical waveguide of the first Mach-Zehnder interference unit respectively.

4. The array power balanced wavelength division multiplexing chip according to claim 3, wherein: The interference unit includes a first sub-interference unit and a second sub-interference unit connected in sequence, and the first sub-interference unit and the second sub-interference unit respectively include: The second asymmetric extension arm is suitable for serving as a delay line to change the phase difference of the optical signal after power distribution; The second directional coupling waveguide is suitable for performing power distribution on the optical signal output by the second asymmetric extension arm.

5. The wavelength division multiplexing chip with array power balance according to claim 4, wherein: The delay line length of the second asymmetric extension arm is twice the delay line length of the first asymmetric extension arm, and the protruding direction of the second asymmetric extension arm is opposite to the protruding direction of the first asymmetric extension arm.

6. The wavelength division multiplexing chip with array power balance according to claim 4, wherein: The Mach-Zehnder interference module also includes two second Mach-Zehnder interference units, the input ports of the two second Mach-Zehnder interference units are respectively connected to the first output optical waveguide and the second output optical waveguide of the first Mach-Zehnder interference unit, and the second Mach-Zehnder interference unit includes a second coupling waveguide, a third asymmetric extension arm, a third directional coupling waveguide, a fourth asymmetric extension arm and a fourth directional coupling waveguide connected in sequence.

7. The wavelength division multiplexing chip with array power balance according to claim 6, wherein: The delay line length of the first asymmetric extension arm is twice the delay line length of the third asymmetric extension arm, and the protruding direction of the first asymmetric extension arm is the same as the protruding direction of the third asymmetric extension arm, the delay line length of the first asymmetric extension arm is the same as the delay line length of the fourth asymmetric extension arm, and the protruding direction of the first asymmetric extension arm is opposite to the protruding direction of the fourth asymmetric extension arm.

8. The wavelength division multiplexing chip with array power balance according to claim 6, wherein: The Mach-Zehnder interference module also includes a plurality of third Mach-Zehnder interference units, the input ports of the third Mach-Zehnder interference units are respectively connected to a plurality of output optical waveguides of the second Mach-Zehnder interference units, and the third Mach-Zehnder interference unit includes a third coupling waveguide, a fifth asymmetric extension arm and a fourth coupling waveguide connected in sequence, wherein the delay line length of the first asymmetric extension arm is four times the delay line length of the fifth asymmetric extension arm, and the protruding direction of the first asymmetric extension arm is the same as the protruding direction of the fifth asymmetric extension arm.

9. The wavelength division multiplexing chip with array power balance according to claim 1, wherein: The heating electrode is formed on the modulation waveguide by deposition.

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