Array power equalized wavelength division multiplexing chip

Abstract

The present disclosure provides a kind of array power equalization wave division multiplexing chip, comprising: substrate;Input optical waveguide, formed on substrate, input optical waveguide is suitable for inputing the optical signal containing multiple wavelengths to be processed;Mach-Zehnder interference module, formed on substrate, Mach-Zehnder interference module is suitable for making the interference of optical signal containing multiple wavelengths to be output from multiple output optical waveguides of Mach-Zehnder interference module respectively;Modulation array module, formed on substrate, modulation array module includes: multiple groups of symmetric modulation arms;Multiple modulation waveguides and multiple heating electrodes with interval are arranged on modulation waveguide, multiple modulation waveguides are connected with multiple groups of symmetric modulation arms respectively, by applying voltage to heating electrode, the output power of different wavelength optical signals is changed using thermo-optic effect, so that the power of each wavelength optical signal is equalized;Multiple transmission electrodes are electrically connected with multiple heating electrodes respectively to transmit external voltage to heating electrode.

Description

Technical Field

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

[0002] To meet the demands of high-speed, high-capacity optical communication systems, wavelength division multiplexing (WDM) technology emerged. Its advantages of high capacity, high compatibility, and low cost have led to its widespread adoption in optical communication systems and all-optical networks. As a component of WDM technology, WDM chips have a significant impact on overall communication performance.

[0003] Currently, multifunctional optical signal processing requires connecting multiple independent discrete components. However, discrete components connected via optical fibers are bulky, and direct end-face coupling of multiple device chips not only increases coupling losses but also affects the stability of the connection, reducing the reliability of the chips and individual discrete components. 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] An embodiment of the present disclosure provides a wavelength division multiplexing (WDM) chip with array power balance, comprising: a substrate; an input optical waveguide formed on the substrate, the input optical waveguide being adapted to input an optical signal comprising multiple wavelengths to be processed; a Mach-Zehnder interference module formed on the substrate, the Mach-Zehnder interference module being adapted to cause the optical signals comprising multiple wavelengths to interfere with each other so as to be outputted from multiple output optical waveguides of the Mach-Zehnder interference module; and a modulation array module formed on the substrate, the modulation array module comprising: multiple groups of symmetrical modulation arms being adapted to respectively receive optical signals of different wavelengths from the multiple output optical waveguides of the Mach-Zehnder interference module; multiple modulation waveguides and multiple heating electrodes spaced apart on the modulation waveguides, the multiple modulation waveguides being respectively connected to the multiple groups of symmetrical modulation arms, and applying voltage to the heating electrodes to change the output power of optical signals of different wavelengths by utilizing a thermo-optical effect, thereby balancing the power of optical signals of each wavelength; and multiple transmission electrodes being respectively electrically connected to the multiple heating electrodes to transmit an 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 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 serving as a delay line to change the phase difference of the above-mentioned optical signal containing multiple wavelengths; a first directional coupling waveguide, suitable for performing power distribution on the optical signal after the phase difference is changed; and an interference section, wherein the above-mentioned interference section allows optical signals of different wavelengths to interfere with each other at different phase differences, thereby outputting them 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 section 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 above-mentioned first asymmetric extension arm is twice the delay line length of the above-mentioned third asymmetric extension arm, and the protruding direction of the above-mentioned first asymmetric extension arm is the same as the protruding direction of the above-mentioned third asymmetric extension arm, the delay line length of the above-mentioned first asymmetric extension arm is the same as the delay line length of the above-mentioned fourth asymmetric extension arm, and the protruding direction of the above-mentioned first asymmetric extension arm is opposite to the protruding direction of the above-mentioned 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 being respectively connected to the plurality of output optical waveguides of the second Mach-Zehnder interference unit, and the third Mach-Zehnder interference unit including 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 the present disclosure, a wavelength division multiplexing chip with array power balance is provided. An input optical waveguide formed on a substrate is used to input an optical signal containing multiple wavelengths to be processed. A Mach-Zehnder interferometer module formed on the substrate is used to cause the optical signals containing multiple wavelengths to interfere with each other, thereby outputting the signals from multiple output optical waveguides of the Mach-Zehnder interferometer module. A modulation array module formed on the substrate includes multiple groups of symmetrical modulation arms, multiple modulation waveguides, multiple heating electrodes spaced apart on the modulation waveguides, and multiple transmission electrodes. 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 the thermo-optical effect, thereby balancing the power of the optical signals of each wavelength. The transmission electrodes electrically connected to the multiple heating electrodes are used to transmit an external voltage to the heating electrodes. This enables the simultaneous integration of the Mach-Zehnder interferometer module and the modulation array module on the substrate, thereby causing the optical signals containing multiple wavelengths to interfere with each other, thereby outputting the signals from the multiple output optical waveguides of the Mach-Zehnder interferometer module while achieving power balance for the optical signals of each wavelength. This avoids the problem of increased coupling loss in multiple chips when discrete components are connected. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a perspective view 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 balance according to an exemplary embodiment of the present disclosure; and

[0019] Figure 5 This is a modulation simulation diagram of multiple channels of a wavelength division multiplexing chip with array power balance after being modulated simultaneously by a modulation array module 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. First coupling waveguide;

[0026] 6. First asymmetric extension arm;

[0027] 7. The first directional coupling waveguide;

[0028] 8. First sub-interference unit;

[0029] 9. Second sub-interference unit;

[0030] 10. Second asymmetric extension arm;

[0031] 11. A second directional coupling waveguide;

[0032] 12. Second coupling waveguide;

[0033] 13. Third asymmetric extension arm;

[0034] 14. The third directional coupling waveguide;

[0035] 15. Fourth asymmetric extension arm;

[0036] 16. Fourth directional coupling waveguide;

[0037] 17. The third coupled waveguide;

[0038] 18. Fifth asymmetric extension arm;

[0039] 19. 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 conjunction 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 presence of the features, steps, operations, and / or components, but do not exclude the presence 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 expressions such as “at least one of A, B, and C, etc.” are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art. For example, “a system having at least one of A, B, and C” should include but is not limited to systems having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, and C, etc. When expressions such as “at least one of A, B, or C, etc.” are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art. For example, “a system having at least one of A, B, or C” should include but is not limited to systems having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, and C, etc.

[0048] To meet the demands of high-speed, high-capacity optical communication systems, wavelength division multiplexing (WDM) technology emerged. Its advantages of high capacity, high compatibility, and low cost have led to its widespread application in optical communication systems and all-optical networks. WDM chips, as a component of WDM technology, impact the overall performance of communications. WDM chips typically utilize an arrayed waveguide grating (AWG) structure. However, the output spectrum of an AWG is Gaussian, which limits the channel bandwidth. Furthermore, the insertion loss of AWGs is high, typically around 4dB. While WDM chips with microring structures can meet the demand for a wide-bandwidth, flat-top spectrum output, they are highly sensitive to process temperature and therefore impose stringent requirements on both the processing technology and the operating environment. To achieve multifunctional processing of optical signals, multiple independent discrete components must be connected. However, discrete components connected via optical fiber are bulky, and direct end-face coupling of multiple components to the chip not only increases coupling losses but also compromises the stability of the connection, reducing the reliability of the chip and the individual discrete components. According to one aspect of the present disclosure, a Mach-Zehnder interferometer module and a modulation array module are simultaneously integrated on a substrate to cause interference in optical signals containing multiple wavelengths, which are then output from multiple output optical waveguides of the Mach-Zehnder interferometer module. Furthermore, the modulation array module is used to achieve power balancing of the optical signals of each wavelength, 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 conjunction with specific embodiments and with reference to the accompanying drawings.

[0050] Figure 1 FIG. 1 is a perspective view of a wavelength division multiplexing chip for array power balancing according to an exemplary embodiment of the present disclosure.

[0051] According to the embodiment of the present disclosure, a wavelength division multiplexing chip with array power balance 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 interferometer module, and a modulation array module. The input optical waveguide 2 is formed on the substrate 1 and is adapted to input optical signals comprising multiple wavelengths to be processed. The Mach-Zehnder interferometer module is formed on the substrate 1 and is adapted to cause the optical signals comprising multiple wavelengths to interfere with each other, thereby outputting them from the multiple output optical waveguides of the Mach-Zehnder interferometer module. The modulation array module is formed on the substrate 1 and includes multiple sets of symmetrical modulation arms 20, multiple modulation waveguides 21, multiple heating electrodes 22 spaced apart on the modulation waveguides 21, and multiple transmission electrodes 23. The multiple sets of symmetrical modulation arms 20 are adapted to receive optical signals of different wavelengths from the multiple output optical waveguides of the Mach-Zehnder interferometer module. The multiple modulation waveguides 21 are connected to the multiple sets of symmetrical modulation arms 20. By applying a voltage to the heating electrodes 22, the output power of the optical signals of different wavelengths is varied through the thermo-optical effect, thereby balancing the power of the optical signals of different wavelengths. 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, substrate 1 is made of silicon. Located on the upper side of substrate 1 is waveguide core 3 (where both the input optical waveguide 2 and the Mach-Zehnder interferometer module are located). Waveguide core 3 is made of germanium-doped silicon dioxide. Optical signals are transmitted through rectangular waveguide 4 within waveguide core 3. Rectangular waveguide 4 measures 4μm x 4μm to ensure single-mode transmission of the optical signal. Located below rectangular waveguide 4 is a lower cladding made of silicon dioxide with a thickness greater than 20μm to prevent leakage of the optical signal into substrate 1 during transmission. Located above rectangular waveguide 4 is an upper cladding made of air, silicon dioxide, or other semiconductor materials with a refractive index lower than that of 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, substrate 1 is made of silicon. Located on the upper side of substrate 1 is waveguide core 3 (where the modulation array module is located). Waveguide core 3 is made of germanium-doped silicon dioxide. Optical signals are transmitted through rectangular waveguide 4 within waveguide core 3. Rectangular waveguide 4 measures 4μm x 4μm to ensure single-mode transmission of the optical signal. Below rectangular waveguide 4 is a lower cladding made of silicon dioxide with a thickness greater than 20μm to prevent optical signal leakage into substrate 1 during transmission. Above rectangular waveguide 4 is an upper cladding made of air, silicon dioxide, or other semiconductor materials with a refractive index lower than that of rectangular waveguide 4. The thickness of the upper cladding is 15μm. In order to achieve temperature-controlled refractive index regulation of the waveguide core 3, an external voltage is transmitted to the heating electrode 22 through a transmission electrode 23. The material of the transmission electrode 23 is, for example, Au or Cr. Heating electrodes 22 made of metal material are deposited at intervals above a 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, an array power-balanced wavelength division multiplexing chip utilizes an input optical waveguide 2 formed on a substrate 1 to input an optical signal containing multiple wavelengths to be processed, and utilizes a Mach-Zehnder interferometer module formed on the substrate 1 to cause the optical signals containing multiple wavelengths to interfere with each other so that the optical signals are output from multiple output optical waveguides of the Mach-Zehnder interferometer module. 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 at intervals on the modulation waveguides 21. The multiple groups of symmetrical modulation arms 20 are adapted to respectively receive optical signals of different wavelengths from multiple output optical waveguides of the Mach-Zehnder interferometer module. 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, using the thermo-optical effect to change the output power of optical signals of different wavelengths, so that the power of optical signals of each wavelength is balanced, and using the transmission electrode 23 electrically connected to the multiple heating electrodes 22 to transmit the external voltage to the heating electrode 22, it is possible to simultaneously integrate the Mach-Zehnder interferometer module and the modulation array module on the substrate 1, so that optical signals containing multiple wavelengths interfere with each other and are output from multiple output optical waveguides of the Mach-Zehnder interferometer module while achieving power balance of optical signals of each wavelength, avoiding the problem of increased coupling loss of multiple chips when discrete devices are connected, reducing the volume, performing multi-functional processing of optical signals, and improving the performance stability of the wavelength division multiplexing chip with array power balance.

[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 interferometer module is a cascade of multiple Mach-Zehnder interferometer units. A single optical signal 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 passing through the cascade of multiple Mach-Zehnder interferometer units, and is output from multiple output optical waveguides of the Mach-Zehnder interferometer module respectively.

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

[0062] According to an embodiment of the present disclosure, a Mach-Zehnder interferometer module includes a first Mach-Zehnder interferometer unit, which includes a first coupling waveguide 5, a first asymmetric extension arm 6, a first directional coupling waveguide 7, and an interferometer. The first asymmetric extension arm 6 is configured to act as a delay line to change the phase difference of an optical signal containing multiple wavelengths. The first directional coupling waveguide 7 is configured to perform power distribution on the optical signal after the phase difference is changed. The interferometer unit generates power by interfering optical signals of different wavelengths at different phase differences, thereby outputting the power from the first and second output optical waveguides of the first Mach-Zehnder interferometer unit.

[0063] According to an embodiment of the present disclosure, the coupling regions of the first coupling waveguide 5 and the first directional coupling waveguide 7 have different lengths, resulting in different amounts of evanescent coupling of the optical signal from one waveguide to the other in the coupling region, i.e., different coupling ratios. The first coupling waveguide 5 is a 3dB coupling waveguide with a coupling ratio of 0.5, while 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 adapted to perform power distribution on the optical signal input by the input optical waveguide 2, then passes through the first asymmetric extension arm 6, which is adapted to act as a delay line to change the phase difference of the optical signal containing multiple wavelengths, and then passes through the first directional coupling waveguide 7, which is adapted to perform power distribution on the optical signal after the phase difference is changed, and couple the optical signals containing multiple wavelengths to interfere with each other. The optical signals of different wavelengths are enhanced or canceled by interference at different phase differences. Then, the optical signal passes through the interference section, and the interference section again interferes with each other at different phase differences through the optical signals of different wavelengths. At this time, the single optical signal passes through the first Mach-Zehnder interferometer unit and is decomposed into two optical signals. The signals are output from the first output optical waveguide and the second output optical waveguide of the first Mach-Zehnder interferometer unit, respectively, to achieve wavelength division multiplexing. The two output optical waveguides output spectral peaks of four channels, namely, 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 section includes a first sub-interference unit 8 and a second sub-interference unit 9 connected in sequence. 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 adapted to function as a delay line to change the phase difference of the optical signal after power distribution. The second directional coupling waveguide 11 is adapted to perform power distribution on 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 finally is 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 of the first asymmetric extension arm 6 is It can be calculated by the following formula (1):

[0070] (1)

[0071] in, is the central wavelength, is the group refractive index of the germanium-doped silica rectangular waveguide 4, 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 of the second asymmetric extension arm 10 is twice the delay line length of the first asymmetric extension arm 6. It can be expressed by the following formula (2):

[0073] (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. 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 regulating 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 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 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, the two optical signals outputted from the first output optical waveguide and the second output optical waveguide of the first Mach-Zehnder interference unit respectively enter the two second Mach-Zehnder interference units. 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 by the first Mach-Zehnder interference unit, and then passes through the third asymmetric extension arm 13, which is suitable for acting as a delay line to change the phase difference of the optical signal, and then passes through the third directional coupling waveguide 14, which is suitable for performing power distribution on the optical signal outputted by the third asymmetric extension arm 13 again, and then passes through the fourth asymmetric extension arm 15, which is suitable for acting as a delay line to change the optical signal 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 re-power distribution of the optical signal output by the fourth asymmetric extension arm 15. 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 interferometer 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 interferometer 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 interferometer 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 interferometer 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 interferometer unit respectively to realize wavelength division multiplexing. 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 of the third asymmetric extension arm 13 is It can be expressed by the following formula (3):

[0080] (3).

[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 of the fourth asymmetric extension arm 15 is It can be expressed by the following formula (4):

[0083] (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 which 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 17, a fifth asymmetric extension arm 18, and a fourth coupling waveguide 19, which are sequentially connected. 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 protrusion direction of the first asymmetric extension arm 6 is the same as the protrusion 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 interferometer units are respectively connected to the third, fourth, fifth, and sixth output optical waveguides of the second Mach-Zehnder interferometer unit. The third coupling waveguide 17 is a 3dB coupling waveguide with a coupling ratio of 0.5, and the fourth coupling waveguide 19 is a 3dB coupling waveguide with a coupling ratio of 0.5. At this time, the four output optical waveguides of the second Mach-Zehnder interferometer unit each output two channel spectral peaks. After passing through the third Mach-Zehnder interferometer unit, the two channel spectral peaks are respectively output from the seventh and eighth output optical waveguides of each third Mach-Zehnder interferometer unit, thereby achieving wavelength division multiplexing, that is, each channel spectral peak is output from eight output optical waveguides.

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

[0088] (5).

[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 arms 20 of the modulation array module, and then enter the modulation waveguide 21 after passing through 3dB coupling waveguides. The coupling ratio of the 3dB coupling waveguide is 0.5. By applying voltage to 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 embodiment of the present disclosure, the Mach-Zehnder interferometer module and the modulation array module are simultaneously integrated on the substrate 1, which reduces the volume of the wavelength division multiplexing chip with array power balance and reduces the coupling loss.

[0093] Figure 4 4 is a diagram showing a spectrum output simulation of a wavelength division multiplexing chip with array power balance according to an exemplary 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 in the unmodulated state, it can be seen from the spectral simulation results that the cascade of multi-stage Mach-Zehnder interferometer units can effectively achieve the output of a large-bandwidth flat-top waveform, and the insertion loss of the 8 channels is less than 0.1dB, ensuring good consistency of the insertion loss of each channel.

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

[0096] According to the embodiments of the present disclosure, Figure 5 As shown, thermal modulation is performed simultaneously on channels 1, 3, 4, and 6. The simulation results show that the four modulated channels can achieve a modulation depth of at least -25 dB. By applying voltage to the heating electrodes 22 corresponding to different output channels, multiple channels can be modulated simultaneously.

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

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

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

[0100] Furthermore, unless specifically described or required to occur sequentially, the order of the steps is not limited to the order listed above and may be varied or rearranged based on desired design requirements. Furthermore, the above embodiments may be mixed and matched with each other or with other embodiments based on design and reliability considerations. That is, the technical features of different embodiments may be freely combined to form more embodiments.

[0101] The embodiments of the present disclosure are described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Although each embodiment has been described separately above, this does not mean that the measures in each embodiment cannot be used in combination to advantage. The scope of the present disclosure is defined by the appended claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art may make various 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, wherein the input optical waveguide is suitable for inputting an optical signal containing multiple wavelengths to be processed; A Mach-Zehnder interference module is formed on the substrate. The Mach-Zehnder interference module is adapted to cause interference in the optical signal containing multiple wavelengths so as to be outputted from multiple output optical waveguides of the Mach-Zehnder interference module. The Mach-Zehnder interference module is a cascade of multiple Mach-Zehnder interference units to increase the bandwidth of the optical signal. The Mach-Zehnder interference module includes: The first Mach-Zehnder interferometer unit, including: a first coupled waveguide; The first asymmetric extension arm is 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 optical signals of different wavelengths to interfere with each other at different phase differences, thereby outputting the signals from the first output optical waveguide and the second output optical waveguide of the first Mach-Zehnder interferometer, respectively. 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; a second directional coupling waveguide, adapted to perform power distribution on the optical signal output by the second asymmetric extension arm; two second Mach-Zehnder interferometer units, the input ports of the two second Mach-Zehnder interferometer units being respectively connected to the first output optical waveguide and the second output optical waveguide of the first Mach-Zehnder interferometer unit, the second Mach-Zehnder interferometer unit comprising 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; and 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 spaced apart on the modulation waveguides, the plurality of modulation waveguides being respectively connected to the plurality of groups of symmetrical modulation arms, wherein a voltage is applied to the heating electrodes to change the output power of optical signals of different wavelengths by utilizing a thermo-optical effect, so as to balance the power of optical signals of various wavelengths; and The plurality of transmission electrodes are electrically connected to the plurality of heating electrodes respectively to transmit external voltage to the heating electrodes.

2. The wavelength division multiplexing chip with array power balance according to claim 1, 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.

3. The wavelength division multiplexing chip with array power balance according to claim 1, 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.

4. The wavelength division multiplexing chip with array power balance according to claim 1, wherein: The Mach-Zehnder interference module further includes a plurality of third Mach-Zehnder interference units, wherein 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.

5. 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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