CN209433059U - Temperature insensitive Mach-Zehnder interferometer - Google Patents

Abstract

The utility model provides a temperature-insensitive Mach-Zehnder interferometer, comprising: a first mode converter; a second mode converter, which is located on one side of the first mode converter and has a distance from the first mode converter; The arm is located between the first mode converter and the second mode converter, one end is connected to the first mode converter, and the other end is connected to the second mode converter; the connecting arm includes a straight waveguide connecting arm. The temperature insensitive Mach-Zehnder interferometer of the utility model can be insensitive to temperature by setting parameters such as the width and thickness of the connecting arm.

Description

Temperature insensitive Mach-Zehnder interferometer

technical field

The utility model belongs to the field of optical technology, in particular to a temperature-insensitive Mach-Zehnder interferometer.

Background technique

A Mach-Zehnder Modulator (MZI) is widely used in technical fields such as optical signal modulation. Then, the existing Mach-Zehnder interferometers basically adopt a double-connected arm structure, and the existing Mach-Zehnder interferometers are generally sensitive to temperature, greatly affected by temperature, complex in structure, and large in size.

Utility model content

In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a temperature-insensitive Mach-Zehnder interferometer, which is used to solve the problem that the Mach-Zehnder interferometer in the prior art is relatively sensitive to temperature and is affected by temperature. Large impact, complex structure, large size and other issues.

In order to achieve the above purpose and other related purposes, the utility model provides a temperature-insensitive Mach-Zehnder interferometer, the temperature-insensitive Mach-Zehnder interferometer comprising:

a first mode converter;

a second mode converter located on one side of the first mode converter and spaced from the first mode converter;

A connecting arm, located between the first mode converter and the second mode converter, one end of the connecting arm is connected to the first mode converter, and the other end is connected to the second mode converter ; The connecting arm includes a straight waveguide connecting arm.

As a preferred solution of the present invention, the first mode converter includes: an input waveguide, a first asymmetric tapered waveguide, a first straight waveguide, and a second asymmetric tapered waveguide; wherein, the input waveguide, The first asymmetric tapered waveguide, the straight waveguide and the second asymmetric tapered waveguide are connected in sequence; the second asymmetric tapered waveguide is connected to the connecting arm;

The second mode converter includes a third asymmetric tapered waveguide, a second straight waveguide, a fourth asymmetric tapered waveguide, and an output waveguide; wherein, the third asymmetric tapered waveguide, the second straight waveguide 1. The fourth asymmetric tapered waveguide is connected to the output waveguide in sequence; the third asymmetric tapered waveguide is connected to the connecting arm.

As a preferred solution of the present invention, one end of the first asymmetric tapered waveguide is a narrow end face, and the other end is a wide end face, and the narrow end face of the first asymmetric tapered waveguide is connected to the input waveguide , the wide end face of the first asymmetric tapered waveguide is connected to the first straight waveguide;

One end of the second asymmetric tapered waveguide is a narrow end face, and the other end is a wide end face, the wide end face of the second asymmetric tapered waveguide is connected to the first straight waveguide, and the second asymmetric tapered waveguide The narrow end face of the shaped waveguide is connected to the connecting arm;

One end of the third asymmetric tapered waveguide is a narrow end face, and the other end is a wide end face, the narrow end face of the third asymmetric tapered waveguide is connected to the connecting arm, and the third asymmetric tapered waveguide The wide end face of is connected to the second straight waveguide;

One end of the fourth asymmetric tapered waveguide is a narrow end face, and the other end is a wide end face, the wide end face of the fourth asymmetric tapered waveguide is connected to the second straight waveguide, and the fourth asymmetric tapered waveguide The narrow end face of the shaped waveguide is connected to the output waveguide.

As a preferred solution of the present invention, the width of the wide end face of the first asymmetric tapered waveguide and the width of the wide end face of the second asymmetric tapered waveguide are the same as the width of the first straight waveguide , the width of the wide end surface of the third asymmetric tapered waveguide and the width of the wide end surface of the fourth asymmetric tapered waveguide are the same as the width of the second straight waveguide.

As a preferred solution of the present invention, the width of the input waveguide is 0.45 μm to 0.55 μm; the width of the wide end face of the first tapered waveguide is 2.1 μm to 2.2 μm, and the width of the first tapered waveguide The width of the narrow end face is 0.45 μm-0.55 μm, the length of the first tapered waveguide is 8.05 μm-8.15 μm; the width of the first straight waveguide is 2.1 μm-2.2 μm, the length of the first straight waveguide is 4.95 μm to 5.05 μm; the width of the wide end surface of the second tapered waveguide is 2.1 μm to 2.2 μm, the width of the narrow end surface of the second tapered waveguide is 1.15 μm to 1.25 μm, and the width of the second tapered waveguide The length of the tapered waveguide is 6.25 μm to 6.35 μm; the width of the wide end surface of the third tapered waveguide is 2.1 μm to 2.2 μm, and the width of the narrow end surface of the third tapered waveguide is 1.15 μm to 1.25 μm. The length of the third tapered waveguide is 6.25 μm to 6.35 μm; the width of the second straight waveguide is 2.1 μm to 2.2 μm, and the length of the second straight waveguide is 4.95 μm to 5.05 μm; the fourth tapered waveguide The width of the wide end surface of the tapered waveguide is 2.1 μm to 2.2 μm, the width of the narrow end surface of the fourth tapered waveguide is 0.45 μm to 0.55 μm, and the length of the fourth tapered waveguide is 8.05 μm to 8.15 μm; The width of the input waveguide is 0.45 μm to 0.55 μm.

As a preferred solution of the present invention, the thickness of the first mode converter, the thickness of the second mode converter and the thickness of the connecting arm are all 215nm-225nm.

As a preferred solution of the present invention, the temperature-insensitive Mach-Zehnder interferometer also includes a first reverse cone coupler and a second reverse cone coupler; wherein, the first reverse cone coupler The coupler includes two input ends and an output end, and the output end of the first reverse taper coupler is connected to the end of the first mode converter away from the connecting arm; the second reverse taper The taper coupler includes an input end and two output ends, and the input end of the second reverse taper coupler is connected to an end of the second mode converter away from the connecting arm.

As a preferred solution of the present invention, the temperature-insensitive Mach-Zehnder interferometer further includes a base, the base includes the underlying silicon layer and the buried oxide layer in the SOI substrate, the first mode converter, the Both the connecting arm and the second mode converter are formed by etching the top silicon layer in the SOI substrate.

As a preferred solution of the present invention, the temperature-insensitive Mach-Zehnder interferometer further includes a protective layer, the protective layer is located on the upper surface of the buried oxide layer, and completely covers the first mode converter, The connecting arm and the second mode converter.

As a preferred solution of the present invention, the width of the connecting arm is 646nm.

As mentioned above, the temperature-insensitive Mach-Zehnder interferometer of the present invention has the following beneficial effects:

The device structure in the temperature-insensitive Mach-Zehnder interferometer of the present invention is obtained based on SOI substrate preparation, because the thermo-optic coefficient of silicon in the SOI substrate is very large (up ^to 1.86×10-4 RIU/K, where , RIU is the refractive index unit), which can cause considerable wavelength drift (about 80pm/K) with temperature. On this basis, the temperature insensitivity can be realized by setting parameters such as the width and thickness of the connecting arm; At the same time, the temperature-insensitive Mach-Zehnder interferometer of the utility model can be compatible with the CMOS process and is convenient for batch production;

The temperature insensitive Mach-Zehnder interferometer of the utility model can output the outgoing light of TE ₀ mode and TE ₁ mode at the output end no matter the incident light of TE ₀ mode or the input light of TE ₁ mode is input at the input end;

In the temperature-insensitive Mach-Zehnder interferometer of the utility model, two mode converters are connected through a connecting arm, the structure is simple, and the loss is small;

The width of the straight waveguide in the asymmetric tapered waveguide in the temperature-insensitive Mach-Zehnder interferometer of the utility model can be adjusted in a large range (±50nm) without affecting the performance of the device, and can be used on the silicon photonics process platform Achieve high-quality mass production.

Description of drawings

Fig. 1 to Fig. 3 show the structural representation of the temperature-insensitive Mach-Zehnder interferometer provided by the utility model; Wherein, Fig. 1 and Fig. 3 show the top view structure schematic diagram of the temperature-insensitive Mach-Zehnder interferometer of two different examples, FIG. 2 shows a schematic diagram of a three-dimensional structure of an example temperature-insensitive Mach-Zehnder interferometer.

Fig. 4 shows a top view structural diagram of the first mode converter in the temperature-insensitive Mach-Zehnder interferometer provided by the present invention.

Fig. 5 shows a schematic top view of the second mode converter in the temperature-insensitive Mach-Zehnder interferometer provided by the present invention.

Fig. 6 shows the curves of the width of the connecting arm and the effective refractive index of different modes of incident light relative to the rate of change of temperature in the temperature-insensitive Mach-Zehnder interferometer provided by the utility model; wherein, curve ① is incident light TE ₀ Mode of incident light, curve ② is incident light of TE ₁ mode.

Fig. 7 and Fig. 8 show the curve diagram of incident light wavelength and input loss under two different temperature conditions of 26.85 ℃ and 56.85 ℃ for the temperature-insensitive Mach-Zehnder interferometer provided by the utility model; wherein, Fig. 7 is based on the length of the connecting arm 560 μm, the incident light is TE ₀ mode, and the output light is TE ₀ mode as an example; in Figure 8, the length of the connecting arm is 1100 μm, the incident light is TE ₀ mode, and the output light is TE ₀ mode as an example.

Fig. 9 to Fig. 12 show the graph of connecting arm length and input loss when connecting arm of different widths in the temperature insensitive Mach-Zehnder interferometer provided by the utility model; Wherein, input light is TE in Fig. 9 and Fig. 10 ₀ mode, the output light is TE ₀ mode and TE ₁ mode; in Figure 11 and Figure 12, the input light is TE ₁ mode, and the output light is TE ₀ mode and TE ₁ mode; in Figure 9 to Figure 12, curve ① is the first straight The curve when the width of the waveguide or the second straight waveguide is 2150nm, the curve ② is the curve when the width of the first straight waveguide or the second straight waveguide is (2150-50)nm, the curve ③ is the first straight waveguide or the second straight waveguide The curve when the width of the waveguide is (2150+50)nm.

Component designation description

10 first mode converter

101 Input waveguide

102 The first asymmetric tapered waveguide

103 The first straight waveguide

104 The second asymmetric tapered waveguide

11 Second Mode Converter

111 The third asymmetric tapered waveguide

112 Second straight waveguide

113 The fourth asymmetric tapered waveguide

114 output waveguide

12 connecting arm

13 First reverse tapered coupler

14 Second reverse tapered coupler

15 bases

151 Bottom silicon layer

152 buried oxide layer

16 protective layer

Detailed ways

The implementation of the present utility model is illustrated by specific specific examples below, and those skilled in the art can easily understand other advantages and effects of the present utility model from the content disclosed in this specification.

See Figures 1 through 11. It should be noted that the structures, proportions, sizes, etc. shown in the drawings attached to this specification are only used to match the content disclosed in the specification, for those who are familiar with this technology to understand and read, and are not used to limit the implementation of the utility model Therefore, it has no technical substantive meaning. Any modification of structure, change of proportional relationship or adjustment of size shall still fall within the scope of The technical content disclosed by the utility model must be within the scope covered. At the same time, terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description and are not used to limit this specification. The practicable range of the utility model, and the change or adjustment of its relative relationship, without any substantial change in the technical content, shall also be regarded as the practicable scope of the utility model.

Please refer to Fig. 1, the utility model provides a kind of temperature-insensitive Mach-Zehnder interferometer, and described temperature-insensitive Mach-Zehnder interferometer comprises: first mode converter 10; Second mode converter 11, described second The mode converter 11 is located on one side of the first mode converter 10 and has a distance from the first mode converter 10; the connecting arm 12 is located between the first mode converter 10 and the first mode converter 10. Between the second mode converter 11, one end of the connecting arm 12 is connected to the first mode converter 10, and the other end is connected to the second mode converter 11; the connecting arm 12 includes a straight waveguide connecting arm.

As an example, as shown in Figure 2 and Figure 3, the temperature insensitive Mach-Zehnder interferometer also includes a first reverse cone coupler 13 and a second reverse cone coupler 14; wherein, the first Reverse conical coupler 13 comprises two input ends (Port1 and Port2 among Fig. 3) and an output end, the output end of described first reverse conical coupler 13 and described first mode converter 10 One end away from the connecting arm 12 is connected; the second reverse tapered coupler 14 includes an input port and two output ports (Port3 and Port4 as in Fig. 3), the second reverse tapered coupler An input end of the coupler 14 is connected to an end of the second mode converter 11 away from the connecting arm 12 .

As an example, as shown in FIG. 2, the temperature-insensitive Mach-Zehnder interferometer further includes a substrate 15, the substrate 15 includes an underlying silicon layer 151 and a buried oxide layer 152 in an SOI substrate, and the first mode conversion The device 10, the connecting arm 12 and the second mode converter 11 are all formed by etching the top silicon layer in the SOI substrate. The first mode converter 10, the connecting arm 12 and the second mode converter 11 in the temperature-insensitive Mach-Zehnder interferometer of the present utility model are prepared based on SOI substrates. Silicon has a large thermo-optic coefficient (up to 1.86×10 ^-4 RIU/K, where RIU is the unit of refractive index), which can cause a considerable wavelength shift (about 80pm/K) with temperature. Based on this In addition, temperature insensitivity can be achieved by setting parameters such as the width and thickness of the connecting arm 12; at the same time, the temperature insensitivity Mach-Zehnder interferometer of the present invention can be compatible with the CMOS process and is convenient for mass production.

As an example, as shown in FIG. 2, the temperature-insensitive Mach-Zehnder interferometer further includes a protective layer 16, the protective layer 16 is located on the upper surface of the buried oxide layer 152, and completely covers the first mode conversion 10, the connecting arm 12 and the second mode converter 11, so as to protect the first mode converter 10, the connecting arm 12 and the second mode converter 11. The protection layer 16 may include but not limited to a silicon oxide layer.

As an example, as shown in FIG. 4 , the first mode converter 10 includes: an input waveguide 101, a first asymmetric tapered waveguide 102, a first straight waveguide 103 and a second asymmetric tapered waveguide 104; wherein, the The input waveguide 101, the first asymmetric tapered waveguide 102, the straight waveguide 103 and the second asymmetric tapered waveguide 104 are sequentially connected; the second asymmetric tapered waveguide 104 is connected to the first asymmetric waveguide The straight waveguide 103 is connected, specifically, the end of the second asymmetric tapered waveguide 104 away from the first straight waveguide 103 is connected with the connecting arm 12 .

As an example, as shown in FIG. 5, the second mode converter 11 includes a third asymmetric tapered waveguide 111, a second straight waveguide 112, a fourth asymmetric tapered waveguide 113, and an output waveguide 114; wherein, the The third asymmetric tapered waveguide 111, the second straight waveguide 112, the fourth asymmetric tapered waveguide 113 and the output waveguide 114 are sequentially connected; the third asymmetric tapered waveguide 111 is connected to the The connecting arms 12 are connected.

As an example, as shown in FIG. 4, one end of the first asymmetric tapered waveguide 102 is a narrow end face, the other end of the first asymmetric tapered waveguide 102 is a wide end face, and the first asymmetric tapered waveguide 102 is a wide end face. The narrow end face of the waveguide 102 is connected with the input waveguide phase 101, the wide end face of the first asymmetric tapered waveguide 102 is connected with the first straight waveguide 103; one end of the second asymmetric tapered waveguide 104 is a narrow end face, the other end of the second asymmetric tapered waveguide 104 is a wide end face, the wide end face of the second asymmetric tapered waveguide 104 is connected to the first straight waveguide 103, and the second asymmetric tapered waveguide 104 is connected to the first straight waveguide 103. The narrow end surface of the symmetrical tapered waveguide 104 is connected to the connecting arm 12 .

As an example, as shown in FIG. 5, one end of the third asymmetric tapered waveguide 111 is a narrow end face, the other end of the third asymmetric tapered waveguide 111 is a wide end face, and the third asymmetric tapered waveguide 111 is a wide end face. The narrow end face of the waveguide 111 is connected with the connecting arm 12, the wide end face of the third asymmetric tapered waveguide 111 is connected with the second straight waveguide 112; one end of the fourth asymmetric tapered waveguide 113 The other end of the fourth asymmetric tapered waveguide 113 is a wide end face, the wide end face of the fourth asymmetric tapered waveguide 113 is connected to the second straight waveguide 112, and the fourth asymmetric tapered waveguide 113 is connected to the second straight waveguide 112. The narrow end face of the symmetrical tapered waveguide 113 is connected to the output waveguide 114 .

As an example, the width of the wide end face of the first asymmetric tapered waveguide 102 and the width W3 of the wide end face of the second asymmetric tapered waveguide 104 are both the same as the width W4 of the first straight waveguide 103, The width W8 of the wide end surface of the third asymmetric tapered waveguide 111 and the width W10 of the wide end surface of the fourth asymmetric tapered waveguide 113 are both the same as the width W9 of the second straight waveguide 112 .

By using the first asymmetric tapered waveguide 102, the second asymmetric tapered waveguide 104, the third asymmetric tapered waveguide 111 and the fourth asymmetric tapered waveguide 113, since the first The asymmetry of the structure of the first mode converter 10 and the second mode converter 11 in the y direction (that is, the width direction of the first straight waveguide 103 and the width direction of the second straight waveguide 112) makes the incident The incident light of the TE ₀ mode will be transmitted on different effective lengths when passing through the first mode converter 10 and the second mode converter 11, by setting the width of the first straight waveguide 103 and the The width of the second straight waveguide 112 can make the incident light of the TE ₀ mode not fully converted into the TE ₁ mode, so that the output light is output light of a mixed mode including the TE ₀ mode and the TE ₁ mode.

As an example, the width of the input waveguide is 0.45 μm to 0.55 μm; the width of the wide end surface of the first tapered waveguide is 2.1 μm to 2.2 μm, and the width of the narrow end surface of the first tapered waveguide is 0.45 μm ~ 0.55 μm, the length of the first tapered waveguide is 8.05 μm ~ 8.15 μm; the width of the first straight waveguide is 2.1 μm ~ 2.2 μm, and the length of the first straight waveguide is 4.95 μm ~ 5.05 μm; The width of the wide end surface of the second tapered waveguide is 2.1 μm to 2.2 μm, the width of the narrow end surface of the second tapered waveguide is 1.15 μm to 1.25 μm, and the length of the second tapered waveguide is 6.25 μm ~6.35μm; the width of the wide end surface of the third tapered waveguide is 2.1μm～2.2μm, the width of the narrow end surface of the third tapered waveguide is 1.15μm～1.25μm, the width of the third tapered waveguide The length is 6.25 μm to 6.35 μm; the width of the second straight waveguide is 2.1 μm to 2.2 μm, and the length of the second straight waveguide is 4.95 μm to 5.05 μm; the width of the wide end surface of the fourth tapered waveguide 2.1 μm to 2.2 μm, the width of the narrow end face of the fourth tapered waveguide is 0.45 μm to 0.55 μm, the length of the fourth tapered waveguide is 8.05 μm to 8.15 μm; the width of the input waveguide is 0.45 μm ~0.55 μm.

It should be noted that there needs to be a one-to-one correspondence between the above-mentioned size parameters within the above-mentioned range, and a few examples are used below to illustrate: For example, in the first example, the width W1 of the input waveguide 101 is 0.5 μm; The width W3 of the wide end surface of the first tapered waveguide 102 is 1.9 μm, the width W2 of the narrow end surface of the first tapered waveguide 102 is 0.5 μm, and the length L1 of the first tapered waveguide 102 is 7.6 μm; The width W4 of the first straight waveguide 103 can be 1.9 μm, the length L2 of the first straight waveguide 103 can be 3.6 μm; the width W5 of the wide end face of the second tapered waveguide 104 can be 1.9 μm, so The width W6 of the narrow end surface of the second tapered waveguide 104 can be 1.2 μm, the length L3 of the second tapered waveguide 104 can be 5.1 μm; the width W8 of the wide end surface of the third tapered waveguide 111 is 1.9 μm. μm, the width W7 of the narrow end face of the third tapered waveguide 111 is 1.2 μm, the length L4 of the third tapered waveguide 111 is 5.1 μm; the width W9 of the second straight waveguide 112 is 1.9 μm, so The length L5 of the second straight waveguide 112 is 3.6 μm; the width W10 of the wide end surface of the fourth tapered waveguide 113 can be 1.9 μm, and the width W11 of the narrow end surface of the fourth tapered waveguide 113 can be 0.5 μm , the length L6 of the fourth tapered waveguide 113 may be 7.6 μm; the width W12 of the input waveguide 114 may be 0.5 μm. In the second example, the width W1 of the input waveguide 101 is 0.5 μm; the width W3 of the wide end surface of the first tapered waveguide 102 is 1.95 μm, and the width W2 of the narrow end surface of the first tapered waveguide 102 is 0.5 μm, the length L1 of the first tapered waveguide 102 is 7.6 μm; the width W4 of the first straight waveguide 103 may be 1.95 μm, and the length L2 of the first straight waveguide 103 may be 3.6 μm; The width W5 of the wide end surface of the second tapered waveguide 104 may be 1.95 μm, the width W6 of the narrow end surface of the second tapered waveguide 104 may be 1.2 μm, and the length L3 of the second tapered waveguide 104 may be is 5.1 μm; the width W8 of the wide end surface of the third tapered waveguide 111 is 1.95 μm, the width W7.6 of the narrow end surface of the third tapered waveguide 111 is 1.2 μm, and the third tapered waveguide 111 The length L4 of the second straight waveguide 112 is 5.1 μm; the width W9 of the second straight waveguide 112 is 1.95 μm, and the length L5 of the second straight waveguide 112 is 3.6 μm; the width W10 of the wide end surface of the fourth tapered waveguide 113 can be The width W11 of the narrow end face of the fourth tapered waveguide 113 can be 0.5 μm, the length L6 of the fourth tapered waveguide 113 can be 7.6 μm; the width W12 of the input waveguide 114 can be 0.5 μm μm. In the third example, the width W1 of the input waveguide 101 is 0.5 μm; the width W3 of the wide end surface of the first tapered waveguide 102 is 2.05 μm, and the width W2 of the narrow end surface of the first tapered waveguide 102 is 0.5 μm, the length L1 of the first tapered waveguide 102 is 7.6 μm; the width W4 of the first straight waveguide 103 may be 2.05 μm, and the length L2 of the first straight waveguide 103 may be 3.6 μm; The width W5 of the wide end surface of the second tapered waveguide 104 may be 2.05 μm, the width W6 of the narrow end surface of the second tapered waveguide 104 may be 1.2 μm, and the length L3 of the second tapered waveguide 104 may be is 5.1 μm; the width W8 of the wide end surface of the third tapered waveguide 111 is 2.05 μm, the width W7.9 of the narrow end surface of the third tapered waveguide 111 is 1.2 μm, and the third tapered waveguide 111 The length L4 of the second straight waveguide 112 is 5.1 μm; the width W9 of the second straight waveguide 112 is 2.05 μm, and the length L5 of the second straight waveguide 112 is 3.6 μm; the width W10 of the wide end surface of the fourth tapered waveguide 113 can be The width W11 of the narrow end face of the fourth tapered waveguide 113 can be 0.5 μm, the length L6 of the fourth tapered waveguide 113 can be 7.6 μm; the width W12 of the input waveguide 114 can be 0.5 μm μm. In the fourth example, the width W1 of the input waveguide 101 is 0.5 μm; the width W3 of the wide end surface of the first tapered waveguide 102 is 2.15 μm, and the width W2 of the narrow end surface of the first tapered waveguide 102 The length L1 of the first tapered waveguide 102 is 8.1 μm; the width W4 of the first straight waveguide 103 can be 2.15 μm, and the length L2 of the first straight waveguide 103 can be 5 μm; The width W5 of the wide end face of the second tapered waveguide 104 can be 2.15 μm, the width W6 of the narrow end face of the second tapered waveguide 104 can be 1.2 μm, and the length L3 of the second tapered waveguide 104 can be 6.3 μm; the width W8 of the wide end face of the third tapered waveguide 111 is 2.15 μm, the width W8.1 of the narrow end face of the third tapered waveguide 111 is 1.2 μm, and the width W8.1 of the third tapered waveguide 111 The length L4 is 6.3 μm; the width W9 of the second straight waveguide 112 is 2.15 μm, and the length L5 of the second straight waveguide 112 is 5 μm; the width W10 of the wide end surface of the fourth tapered waveguide 113 can be 2.15 μm μm, the width W11 of the narrow end face of the fourth tapered waveguide 113 may be 0.5 μm, the length L6 of the fourth tapered waveguide 113 may be 8.1 μm; the width W12 of the input waveguide 114 may be 0.5 μm. In the fifth example, the width W1 of the input waveguide 101 is 0.5 μm; the width W3 of the wide end surface of the first tapered waveguide 102 is 2.2 μm, and the width W2 of the narrow end surface of the first tapered waveguide 102 The length L1 of the first tapered waveguide 102 is 8.5 μm; the width W4 of the first straight waveguide 103 can be 2.2 μm, and the length L2 of the first straight waveguide 103 can be 5 μm; The width W5 of the wide end face of the second tapered waveguide 104 can be 2.2 μm, the width W6 of the narrow end face of the second tapered waveguide 104 can be 1.2 μm, and the length L3 of the second tapered waveguide 104 can be 6.3 μm; the width W8 of the wide end face of the third tapered waveguide 111 is 2.2 μm, the width W8.48 of the narrow end face of the third tapered waveguide 111 is 1.2 μm, and the width W8.48 of the third tapered waveguide 111 is The length L4 is 6.3 μm; the width W9 of the second straight waveguide 112 is 2.2 μm, and the length L5 of the second straight waveguide 112 is 5 μm; the width W10 of the wide end face of the fourth tapered waveguide 113 can be 2.2 μm. μm, the width W11 of the narrow end face of the fourth tapered waveguide 113 may be 0.5 μm, the length L6 of the fourth tapered waveguide 113 may be 8.1 μm; the width W12 of the input waveguide 114 may be 0.5 μm.

As an example, the thickness of the first mode converter 10, the thickness of the second mode converter 11 and the thickness of the connecting arm 12 can be set according to actual needs. Preferably, the first mode converter 10, the thickness of the second mode converter 11 and the thickness of the connecting arm 12 may all be 215 nm to 225 nm; more preferably, in this embodiment, the thickness of the first mode converter 10, The thickness of the second mode converter 11 and the connecting arm 12 are 220 nm.

As an example, the width of the connecting arm 12 can be set according to actual needs. Preferably, the width of the connecting arm 12 is 646nm; The curves of the width of the arm and the rate of change of the effective refractive index of the incident light in different modes with respect to the temperature, the corresponding when the incident light of the two modes has the same rate of change of the effective refractive index with respect to the temperature (d _neff /dT) The width of the connecting arm 12 is the corresponding width of the connecting arm 12 when temperature insensitivity can be realized. Please refer to Fig. 7 and Fig. 8, as can be seen from Fig. 7 and Fig. 8, the temperature insensitive Mach of the present utility model has The Del interferometer has approximately the same performance at different temperatures, that is, the performance of the temperature-insensitive Mach-Zehnder interferometer of the present utility model is not greatly affected by temperature, that is, Fig. 7 and Fig. 8 further prove the temperature of the present utility model Insensitive Mach-Zehnder interferometers are not sensitive to temperature.

Please refer to Fig. 9 to Fig. 12. It can be seen from Fig. 9 to Fig. 12 that the temperature-insensitive Mach-Zehnder interferometer of the present invention can obtain TE no matter the incident light of TE ₀ mode or TE ₁ mode is input Mixed mode exit light of ₀ mode and TE ₁ mode. It can be seen from Fig. 9 to Fig. 12 that the temperature-insensitive Mach-Zehnder interferometer of the present invention will not affect the temperature when the width of the first straight waveguide 103 and the width of the second straight waveguide 112 changes within the range of ±50nm. The temperature insensitivity has a clear effect on the performance of the Mach-Zehnder interferometer.

In summary, the utility model provides a temperature-insensitive Mach-Zehnder interferometer, the temperature-insensitive Mach-Zehnder interferometer includes: a first mode converter; a second mode converter, located in the first mode One side of the converter, and has a distance from the first mode converter; the connecting arm is located between the first mode converter and the second mode converter, and one end of the connecting arm is connected to the first mode converter. The mode converter is connected, and the other end is connected with the second mode converter; the connecting arm includes a straight waveguide connecting arm. The device structure in the temperature-insensitive Mach-Zehnder interferometer of the present invention is obtained based on SOI substrate preparation, because the thermo-optic coefficient of silicon in the SOI substrate is very large (up to 1.86×10 ^- 4RIU/K, wherein, RIU is the refractive index unit), which can cause a considerable wavelength shift (about 80pm/K) with temperature. On this basis, parameters such as the width and thickness of the connecting arm can be set to be insensitive to temperature; at the same time , the temperature-insensitive Mach-Zehnder interferometer of the utility model can be compatible with CMOS technology, and is convenient for mass production; the temperature-insensitive Mach-Zehnder interferometer of the utility model no matter the incident light of the TE0 mode or the TE1 mode is input at the input end Input light, its output port can output the outgoing light of TE0 mode and TE1 mode; in the temperature insensitive Mach-Zehnder interferometer of the utility model, two mode converters are connected by a connecting arm, the structure is simple, and it has a smaller loss; the width of the straight waveguide in the asymmetric tapered waveguide in the temperature-insensitive Mach-Zehnder interferometer of the present utility model can be adjusted in a large range (±50nm) without affecting the performance of the device, and can be used in silicon photonics The process platform enables high-quality mass production.

The above-mentioned embodiments only illustrate the principles and effects of the present utility model, but are not intended to limit the present utility model. Anyone familiar with this technology can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed in the utility model should still be covered by the claims of the utility model.

Claims (10)

1. a kind of temperature-insensitive Mach-Zehnder interferometers, which is characterized in that the temperature-insensitive Mach Zehnder interferometry Instrument includes:

First mode converter；

Second mode converter, positioned at the side of the first mode converter, and between having with the first mode converter Away from；

Linking arm, between the first mode converter and the second mode converter, described linking arm one end and institute It states first mode converter to be connected, the other end is connected with the second mode converter；The linking arm includes straight wave guide Linking arm.

2. temperature-insensitive Mach-Zehnder interferometers according to claim 1, which is characterized in that

The first mode converter includes: that input waveguide, the first asymmetric tapered transmission line, the first straight wave guide and second are asymmetric Tapered transmission line；Wherein, the input waveguide, the first asymmetric tapered transmission line, the straight wave guide and described second asymmetric Tapered transmission line, which is sequentially connected, to be connect；The second asymmetric tapered transmission line is connected with the linking arm；

The second mode converter include the asymmetric tapered transmission line of third, the second straight wave guide, the 4th asymmetric tapered transmission line and Output waveguide；Wherein, the asymmetric tapered transmission line of the third, second straight wave guide, the 4th asymmetric tapered transmission line and The output waveguide, which is sequentially connected, to be connect；The asymmetric tapered transmission line of third is connected with the linking arm.

3. temperature-insensitive Mach-Zehnder interferometers according to claim 2, which is characterized in that

One end of the first asymmetric tapered transmission line is narrow end surface, and the other end is wide end surface, the first asymmetric conical wave The narrow end surface led is connected with the input waveguide, the wide end surface and first straight wave guide of the first asymmetric tapered transmission line It is connected；

One end of the second asymmetric tapered transmission line is narrow end surface, and the other end is wide end surface, the second asymmetric conical wave The wide end surface led is connected with first straight wave guide, narrow end surface and the linking arm phase of the second asymmetric tapered transmission line Connection；

One end of the asymmetric tapered transmission line of third is narrow end surface, and the other end is wide end surface, the asymmetric conical wave of third The narrow end surface led is connected with the linking arm, wide end surface and the second straight wave guide phase of the asymmetric tapered transmission line of third Connection；

One end of the 4th asymmetric tapered transmission line is narrow end surface, and the other end is wide end surface, the 4th asymmetric conical wave The wide end surface led is connected with second straight wave guide, the narrow end surface of the 4th asymmetric tapered transmission line and the output waveguide It is connected.

4. temperature-insensitive Mach-Zehnder interferometers according to claim 3, which is characterized in that described first is asymmetric The width of the width of the wide end surface of tapered transmission line and the wide end surface of the second asymmetric tapered transmission line with the described first straight wave That leads is of same size, the width of the wide end surface of the asymmetric tapered transmission line of third and the 4th asymmetric tapered transmission line wide end The width in face is of same size with second straight wave guide.

5. temperature-insensitive Mach-Zehnder interferometers according to claim 3, which is characterized in that the input waveguide Width is 0.45 μm~0.55 μm；The width of the wide end surface of the first asymmetric tapered transmission line is 2.1 μm~2.2 μm, described The width of the narrow end surface of first asymmetric tapered transmission line is 0.45 μm~0.55 μm, the length of the first asymmetric tapered transmission line It is 8.05 μm~8.15 μm；The width of first straight wave guide is 2.1 μm~2.2 μm, and the length of first straight wave guide is 4.95 μm~5.05 μm；The width of the wide end surface of the second asymmetric tapered transmission line is 2.1 μm~2.2 μm, and described second is non- The width of the narrow end surface of symmetric pyramid waveguide is 1.15 μm~1.25 μm, and the length of the second asymmetric tapered transmission line is 6.25 μm~6.35 μm；The width of the wide end surface of the asymmetric tapered transmission line of third is 2.1 μm~2.2 μm, and the third is asymmetric The width of the narrow end surface of tapered transmission line is 1.15 μm~1.25 μm, the length of the asymmetric tapered transmission line of third is 6.25 μm~ 6.35μm；The width of second straight wave guide is 2.1 μm~2.2 μm, and the length of second straight wave guide is 4.95 μm~5.05 μ m；The width of the wide end surface of the 4th asymmetric tapered transmission line is 2.1 μm~2.2 μm, the 4th asymmetric tapered transmission line The width of narrow end surface is 0.45 μm~0.55 μm, 8.05 μm~8.15 μm of the length of the 4th asymmetric tapered transmission line.

6. temperature-insensitive Mach-Zehnder interferometers according to claim 1, which is characterized in that the first mode turns The thickness of the thickness of parallel operation, the thickness of the second mode converter and the linking arm is 215nm~225nm.

7. temperature-insensitive Mach-Zehnder interferometers according to claim 1, which is characterized in that the temperature-insensitive It further includes the first reversed taper coupler and the second reversed taper coupler that Mach, which increases Dare interferometer,；Wherein, described first is anti- It include two input terminals and an output end, the output end of the first reversed taper coupler and described the to taper coupler One mode converter is connected far from one end of the linking arm；The second reversed taper coupler include an input terminal and Two output ends, the input terminal and the second mode converter of the second reversed taper coupler are far from the linking arm One end is connected.

8. temperature-insensitive Mach-Zehnder interferometers according to claim 1, which is characterized in that the temperature-insensitive Mach-Zehnder interferometers further include substrate, and the substrate includes bottom silicon layer and buried oxide layer in SOI substrate, first mould Formula converter, the linking arm and the second mode converter are by etching the top silicon layer shape in the SOI substrate At.

9. temperature-insensitive Mach-Zehnder interferometers according to claim 8, which is characterized in that the temperature-insensitive Mach-Zehnder interferometers further include protective layer, and the protective layer is located at the upper surface of the buried oxide layer, and are completely covered described First mode converter, the linking arm and the second mode converter.

10. temperature-insensitive Mach-Zehnder interferometers according to any one of claim 1 to 9, which is characterized in that institute The width for stating linking arm is 646nm.