Low-power-consumption multiple-input-multiple-output thermo-optical switch chip

Abstract

The invention discloses a low-power-consumption multiple-input-multiple-output thermo-optical switch chip which comprises N optical input ports, an N * N optical beam splitter, N spiral waveguide thermo-optical phase shifters, an N * N optical beam combiner and N optical output ports. The N * N light beam splitter and the N * N light beam combiner adopt the same design structure and comprise N single-mode input / output waveguides, N width gradient waveguide transition areas (taper areas) and a multi-mode waveguide area, and each single-mode input and output waveguide is connected to the multi-mode waveguide area through the width gradient waveguide transition area. The spiral waveguide thermo-optic phase shifter comprises two spiral waveguides with different sizes, an S bend with a gradually-changed width and a circular heating electrode. The transmission path of light in the chip can be changed by adjusting the spiral waveguide thermo-optical phase shifter, and the function of optical switch switching is achieved. The invention has the advantages of high integration level, high expandability and low power consumption, and can be used in the field of integrated photon chips.

Description

Technical Field

[0001] The invention belongs to the field of integrated photonic chips and relates to a low-power multi-input multi-output thermo-optical switch chip. Background Art

[0002] In the field of integrated photonic chips, low-power multi-input multi-output thermo-optical switch chips play an important role as one of the basic devices and have always been an important research hotspot in this field. In large-scale optical switch matrix applications, integrated low-power optical switches are very important and play an important role in large-scale integrated photonic circuits. However, the current mainstream multi-input multi-output optical switches generally have problems such as high power consumption and difficulty in integration. Among them, most of the traditional straight waveguide multi-input multi-output thermo-optical switch chips are cascaded from 2×2 optical switches. A large number of 2×2 optical switch chips are required to realize large-scale multi-input multi-output chips. The overall power consumption of the switch is extremely high, and the device size composed of multiple 2×2 optical switches is large, which poses a challenge to large-scale on-chip integration. Therefore, while ensuring that the basic performance of the optical switch is not significantly affected, multi-input multi-output optical switches with small size, low power consumption, low thermal crosstalk, and high integration have become an important research direction. Summary of the invention

[0003] In view of the above problems in the prior art, the present invention proposes a low-power multi-input multi-output thermal optical switch chip, which significantly reduces the power consumption of the optical switch and greatly improves the integration of the multi-input multi-output optical switch.

[0004] A low-power multi-input multi-output thermo-optical switch chip, comprising N optical input ports In1-InN, an N×N optical beam splitter MMI1, N spiral waveguide thermo-optical phase shifters PS1-PSN, an N×N optical beam combiner MMI2, and N optical output ports Out1-OutN; wherein the N optical input ports In1-InN are connected to the input ends of the N spiral waveguide thermo-optical phase shifters PS1-PSN through the N×N optical beam splitter MMI1, the output end of each spiral waveguide thermo-optical phase shifter PS1-PSN is connected to the N×N optical beam combiner MMI2, and all output ports of the N×N optical beam combiner MMI2 are connected to the N optical output ports Out1-OutN; the N×N optical beam splitter MMI1 and the N×N optical beam combiner MMI2 have the same structure, both of which include N single-mode input ports, N single-mode output ports, a multi-mode waveguide region, and a plurality of optical interfaces between the input and output and the multi-mode waveguide region. Width gradient waveguide taper zone; wherein, N single-mode input ports and N single-mode output ports in the optical splitter MMI1 and the beam combiner MMI2 are connected to the multi-mode waveguide zone through the width gradient waveguide taper zone; the signal is input from the single-mode input port, and the signal is output from the single-mode output port; the spiral waveguide thermo-optical phase shifter PS1-PSN is composed of a spiral waveguide, a width gradient S-bend and a TiN heating electrode; two spiral waveguides of different widths are connected through an intermediate width gradient S-bend to form a double spiral optical waveguide; the annular TiN heating electrode is located above the double spiral optical waveguide for phase tuning; a SiO2 cladding is also included between the double spiral optical waveguide and the annular TiN heating electrode; the multi-input and multi-output thermo-optical switch chip controls different spiral waveguide thermo-optical phase shifters PS1-PSN for phase shifting, and realizes switching of different output ports through interference coupling of the optical beam combiner MMI2.

[0005] Furthermore, the spiral waveguide thermo-optic phase shifters PS1-PSN are realized by using the thermo-optic effect of the optical waveguide.

[0006] Furthermore, the thermo-optic switch chip is implemented using the following materials: silicon on insulator, silicon nitride, lithium niobate, organic polymer, silicon oxynitride or silicon dioxide.

[0007] Furthermore, the spiral waveguide in the spiral waveguide thermo-optical phase shifter PS1-PSN consists of two waveguides with widths of 450nm and 600nm, and a gradually varying width S-bend connecting the two, wherein the waveguide gap between the 450nm waveguide and the 600nm waveguide is 600nm.

[0008] Furthermore, N optical input ports In1-InN, N×N optical beam splitter MMI1, N spiral waveguide thermo-optical phase shifters PS1-PSN, N×N optical beam combiner MMI2, and N optical output ports Out1-OutN are integrated on-chip.

[0009] Furthermore, the N×N optical beam splitter can split a single input optical signal into N identical optical signals; the N×N optical beam combiner is used to interfere and couple the N optical input signals and output optical signals from N ports, thereby realizing a multi-input and multi-output optical switch function.

[0010] The low-power multi-input multi-output thermo-optical switch chip of the present invention has the following beneficial effects:

[0011] 1. Compared with the prior art, the specific structure of the spiral waveguide thermo-optical phase shifter and the N×N optical beam splitter and N×N optical combiner in the present invention realizes a multi-input multi-output thermo-optical switch chip with lower power consumption.

[0012] 2. The N×N optical beam splitter MMI1 and the N×N optical beam combiner MMI2 structure of the present invention can reduce the device size, enhance the integration of the multi-input multi-output thermo-optical switch, and further facilitate on-chip integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A schematic diagram of the chip architecture of a low-power multi-input multi-output thermo-optical switch chip provided by the present invention.

[0014] Figure 2 A diagram of power consumption and driving voltage of a spiral waveguide thermo-optical phase shifter provided by the present invention.

[0015] Figure 3 A schematic diagram of the chip architecture of a low-power 3×3 thermo-optical switch chip provided by the present invention.

[0016] Figure 4 This is a diagram of the extinction ratio of the In1-Out1 output state of a low-power 3×3 thermo-optical switch chip provided by the present invention.

[0017] Figure 5 This is a diagram of the extinction ratio of the In1-Out2 output state of a low-power 3×3 thermo-optical switch chip provided by the present invention.

[0018] Figure 6 This is a diagram of the extinction ratio of the output states of the low-power 3×3 thermo-optical switch chip In1-Out3 provided by the present invention.

[0019] Figure 7 This is a diagram of the extinction ratio of the In2-Out1 output state of a low-power 3×3 thermo-optical switch chip provided by the present invention.

[0020] Figure 8 This is a diagram of the In2-Out2 output state extinction ratio of a low-power 3×3 thermo-optical switch chip provided by the present invention.

[0021] Fig. 9This is a diagram of the extinction ratio of the In2-Out3 output state of a low-power 3×3 thermo-optical switch chip provided by the present invention.

[0022] Fig.10 This is a diagram of the extinction ratio of the In3-Out1 output state of a low-power 3×3 thermo-optical switch chip provided by the present invention.

[0023] Fig.11 This is a diagram of the extinction ratio of the In3-Out2 output state of a low-power 3×3 thermo-optical switch chip provided by the present invention.

[0024] Fig.12 This is a diagram of the extinction ratio of the In3-Out3 output state of a low-power 3×3 thermo-optical switch chip provided by the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0026] The present invention discloses a low-power multi-input multi-output thermo-optical switch chip. Through an N×N optical beam splitter MMI1, an input optical signal is divided into N optical signals of equal intensity and input into N spiral waveguide thermo-optical phase shifters PS1-PSN. The thermo-optical effect of the spiral waveguide thermo-optical phase shifters PS1-PSN is used to realize phase control of the input optical signal. The optical signals controlled by the spiral waveguide thermo-optical phase shifters PS1-PSN are combined by the combiner MMI2 and then output from specific output ports Out1-OutN. By adjusting the heating voltage of different spiral waveguide thermo-optical phase shifters PS1-PSN, the switching of N optical signal outputs (Out1-OutN) is controlled, and finally a low-power multi-input multi-output optical switch function is realized.

[0027] According to the above invention ideas, the present invention patent combines the following examples to propose a low-power 3×3 thermo-optic switch chip including: 3 optical input ports (In1-In3), 3×3 optical beam splitter (MMI1), spiral waveguide thermo-optic phase shifter (PS1-PSN), 3×3 optical combiner (MMI2), 3 optical output ports (Out1-Out3). Among them, the overall structure is modeled and analyzed by the transmission matrix method, which is composed of MMI1, spiral waveguide thermo-optic phase shifters PS1-PSN and MMI2.

[0028] The 3×3 optical beam splitter includes 3 optical input ports and 3 optical output ports, a total of 6 ports, and 6 gradient waveguides for connecting single-mode and multi-mode waveguides. The single-mode optical input signal is split through the multi-mode waveguide into 3 identical single-mode optical signals, and the signals are output through the 3 optical output ports.

[0029] The 3×3 optical combiner includes 3 optical input ports and 3 optical output ports, a total of 6 ports, and 6 gradient waveguides for connecting single-mode and multi-mode waveguides. Multiple input single-mode optical signals are interfered through the multi-mode waveguide, and then a specific single-mode output port is selected to output the optical signal.

[0030] The spiral waveguide thermo-optic phase shifter (PS1-PS3) is realized by the optical waveguide thermo-optic effect.

[0031] Figure 1 The present invention provides a schematic diagram of the structure of a low-power multi-input multi-output thermo-optical switch chip, which is mainly composed of the following units: N optical input ports (In1-InN), N×N optical beam splitter (MMI1), N spiral waveguide thermo-optical phase shifters (PS1-PSN), N×N optical combiner (MMI2), and N optical output ports (Out1-OutN). The N optical input ports are connected to the input ends of the N spiral waveguide thermo-optical phase shifters through the N×N optical beam splitter, the output end of each spiral waveguide thermo-optical phase shifter is connected to the N×N optical combiner, and all output ports of the N×N optical combiner are connected to the N optical output ports; the N×N optical beam splitter MMI1 has the same structure as the N×N optical combiner MMI2, and both include N single-mode input ports, N single-mode output ports, a multi-mode waveguide region, and a taper region of gradually changing width waveguides between the input and output and the multi-mode waveguide region. Among them, the N single-mode input and output ports in the optical splitter MMI1 and the beam combiner MMI2 are connected to the multi-mode waveguide area through the taper area of ​​the gradually changing width waveguide; the input signal is input from the single-mode signal end, and the signal is output from the single-mode output end; the spiral waveguide thermo-optical phase shifter PS1-PSN is composed of a spiral waveguide, a gradually changing width S-bend and a TiN heating electrode, and a spiral waveguide with a width of 450nm and a spiral waveguide with a width of 600nm are connected through the intermediate gradually changing width S-bend to form a double spiral waveguide; the circular TiN heating electrode is located above the double spiral waveguide for phase tuning, and the TiN heating electrode is an arc-shaped with a width of 3μm and a length of 93μm. A SiO2 cladding is also included between the double spiral waveguide and the circular heating electrode. In the chip architecture diagram, the optical signal is input into the N×N optical beam splitter from one of the optical input ports. The N×N optical beam splitter divides the input optical signal into N identical signals, and then inputs them into N spiral waveguide thermo-optic phase shifters respectively. After voltage is applied to the TiN heating electrode of the spiral waveguide thermo-optic phase shifter to heat it up and use the thermo-optic effect for phase shifting, the output signal of the spiral waveguide thermo-optic phase shifter is input into the N×N optical combiner. After interference from the N×N optical combiner, the output switching of the N optical output ports is finally realized, realizing the multi-input and multi-output thermo-optical switch function.

[0032] Figure 2The power consumption and driving voltage diagram of a spiral waveguide thermo-optical phase shifter provided by the present invention is shown in FIG. In the voltage operating range of 1.0-2.5V, the optical signal is π-phase shifted by the spiral waveguide thermo-optical phase shifter, and the average power consumption of a single spiral waveguide thermo-optical phase shifter is about 2.45mW.

[0033] Figure 3 This is a schematic diagram of the structure of a low-power 3×3 thermo-optical switch chip provided by the present invention. The multi-input multi-output thermo-optical switch chip is mainly composed of the following units: 3 optical input ports (In1-In3), 3×3 optical beam splitter (MMI1), 3 spiral waveguide thermo-optical phase shifters (PS1-PS3), 3×3 optical combiner (MMI2), and 3 optical output ports (Out1-Out3). The 3×3 optical beam splitter and 3×3 optical combiner are mainly composed of the following units: 3 optical input ports, 3 optical output ports, and a gradient waveguide between a multimode waveguide and a single-mode waveguide. The spiral waveguide thermo-optical phase shifter is mainly composed of a spiral waveguide and a TiN heating electrode. Among them, the spiral waveguide is composed of two widths of 600nm and 450nm, and the waveguide gap is 600nm. In the chip architecture diagram, an optical signal is input from an optical input port into a 3×3 optical beam splitter. The 3×3 optical beam splitter divides the input optical signal into three identical signals, which are then input into three spiral waveguide thermo-optic phase shifters respectively. A voltage is applied to the TiN heating electrode of the spiral waveguide thermo-optic phase shifter to heat it up and use the thermo-optic effect for phase shifting. Then, the output signal of the spiral waveguide thermo-optic phase shifter is input into the 3×3 optical combiner. After interference from the 3×3 optical combiner, the output switching of the three optical output ports is finally realized, thus realizing the 3×3 thermo-optic switch function.

[0034] Figure 4 This is a graph of the extinction ratio of the In1-Out1 output state of a low-power 3×3 thermo-optical switch chip provided by the present invention. In the case of In1 input and Out1 output, the transmittance of the output ports Out2 and Out3 is about -75dB, and there is almost no output optical signal. The transmittance of Out1 is close to 0dB, and the optical signal is output from the Out1 port, and the extinction ratio is 75dB.

[0035] Figure 5 This is a graph of the extinction ratio of the In1-Out2 output state of a low-power 3×3 thermo-optical switch chip provided by the present invention. In the case of In1 input and Out2 output, the transmittance of the output ports Out1 and Out3 is about -75dB, and there is almost no output optical signal. The transmittance of Out2 is close to 0dB, and the optical signal is output from the Out2 port, and the extinction ratio is 75dB.

[0036] Figure 6This is a graph of the extinction ratio of the In1-Out3 output state of a low-power 3×3 thermo-optical switch chip provided by the present invention. In the case of In1 input and Out3 output, the transmittance of the output ports Out1 and Out2 is about -75dB, and there is almost no output optical signal. The transmittance of Out3 is close to 0dB, and the optical signal is output from the Out3 port, and the extinction ratio is 75dB.

[0037] Figure 7 This is a diagram of the extinction ratio of the In2-Out1 output state of a low-power 3×3 thermo-optical switch chip provided by the present invention. When the optical signal is input to the In2 port and output to the Out1 port, the transmittance of the output ports Out2 and Out3 is about -75dB, and there is almost no output optical signal. The transmittance of Out1 is close to 0dB, and the optical signal is output from the Out1 port.

[0038] Figure 8 This is a graph of the extinction ratio of the In2-Out2 output state of a low-power 3×3 thermo-optical switch chip provided by the present invention. When the optical signal is input to the In2 port and output to the Out2 port, the transmittance of the output ports Out1 and Out3 is about -75dB, and there is almost no output optical signal. The transmittance of Out2 is close to 0dB, and the optical signal is output from the Out2 port, and the extinction ratio is 75dB.

[0039] Fig. 9 This is a graph of the extinction ratio of the In2-Out3 output state of a low-power 3×3 thermo-optical switch chip provided by the present invention. When the optical signal is input to the In2 port and output to the Out3 port, the transmittance of the output ports Out1 and Out2 is about -75dB, and there is almost no output optical signal. The transmittance of Out3 is close to 0dB, and the optical signal is output from the Out3 port, and the extinction ratio is 75dB.

[0040] Fig.10 This is a graph of the extinction ratio of the In3-Out1 output state of a low-power 3×3 thermo-optical switch chip provided by the present invention. When the optical signal is input to the In3 port and output to the Out1 port, the transmittance of the output ports Out2 and Out3 is about -75dB, and there is almost no output optical signal. The transmittance of Out1 is close to 0dB, and the optical signal is output from the Out1 port, and the extinction ratio is 75dB.

[0041] Fig.11 This is a graph of the extinction ratio of the In3-Out2 output state of a low-power 3×3 thermo-optical switch chip provided by the present invention. When the optical signal is input to the In3 port and output to the Out2 port, the transmittance of the output ports Out1 and Out3 is about -75dB, and there is almost no output optical signal. The transmittance of Out2 is close to 0dB, and the optical signal is output from the Out2 port, and the extinction ratio is 75dB.

[0042] Fig.12 This is a graph of the extinction ratio of the In3-Out3 output state of a low-power 3×3 thermo-optical switch chip provided by the present invention. When the optical signal is input to the In3 port and output to the Out3 port, the transmittance of the output ports Out1 and Out2 is about -75dB, and there is almost no output optical signal. The transmittance of Out3 is close to 0dB, and the optical signal is output from the Out3 port, and the extinction ratio is 75dB.

[0043] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A low-power multi-input multi-output thermal optical switch chip, characterized in that: It includes N optical input ports In1-InN, an N×N optical beam splitter MMI1, N spiral waveguide thermal optical phase shifters PS1-PSN, an N×N optical combiner MMI2, and N optical output ports Out1-OutN; wherein the N optical input ports In1-InN are connected to the input ends of the N spiral waveguide thermal optical phase shifters PS1-PSN through the N×N optical beam splitter MMI1, the output end of each spiral waveguide thermal optical phase shifter PS1-PSN is connected to the N×N optical combiner MMI2, and all output ports of the N×N optical combiner MMI2 are connected to the N optical output ports Out1-OutN; the N×N optical beam splitter MMI1 has the same structure as the N×N optical combiner MMI2, and both include N single-mode input ports, N single-mode output ports, a multi-mode waveguide region, and a gradual width change between the input and output and the multi-mode waveguide region. Waveguide taper zone; wherein, N single-mode input ports and N single-mode output ports in the optical splitter MMI1 and the beam combiner MMI2 are connected to the multi-mode waveguide zone through the width gradient waveguide taper zone; the signal is input from the single-mode input port, and the signal is output from the single-mode output port; the spiral waveguide thermo-optical phase shifter PS1-PSN is composed of a spiral waveguide, a width gradient S-bend and a TiN heating electrode; two spiral waveguides of different widths are connected through an intermediate width gradient S-bend to form a double spiral optical waveguide; the TiN heating electrode is located above the double spiral optical waveguide for phase tuning; a SiO2 cladding is also included between the double spiral optical waveguide and the heating electrode; the multi-input and multi-output thermo-optical switch chip controls different spiral waveguide thermo-optical phase shifters PS1-PSN for phase shifting, and realizes switching of different output ports through interference coupling of the optical beam combiner MMI2.

2. A low-power multi-input multi-output thermo-optical switch chip according to claim 1, characterized in that: The spiral waveguide thermo-optic phase shifter PS1-PSN is realized by using the thermo-optic effect of optical waveguide.

3. The low-power multi-input multi-output thermo-optical switch chip according to claim 1, characterized in that: Thermo-optic switch chips are implemented using the following materials: silicon on insulator, silicon nitride, lithium niobate, organic polymers, silicon oxynitride or silicon dioxide.

4. The low-power multi-input multi-output thermo-optical switch chip according to claim 1, characterized in that: The spiral waveguide in the spiral waveguide thermo-optical phase shifter PS1-PSN consists of two waveguides with widths of 450nm and 600nm, and a gradually varying width S-bend connecting the two, wherein the waveguide gap between the 450nm waveguide and the 600nm waveguide is 600nm.

5. The low-power multi-input multi-output thermo-optical switch chip according to claim 1, characterized in that: N optical input ports In1-InN, N×N optical beam splitter MMI1, N spiral waveguide thermo-optical phase shifters PS1-PSN, N×N optical beam combiner MMI2, and N optical output ports Out1-OutN are integrated on-chip.

6. The low-power multi-input multi-output thermo-optical switch chip according to claim 1, characterized in that: The N×N optical beam splitter can split a single input optical signal into N identical optical signals; the N×N optical beam combiner is used to interference couple the N optical input signals and output optical signals from N ports, thus realizing the multi-input multi-output optical switch function.

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