Optical waveguide sensor, manufacturing method thereof and electronic equipment

Abstract

The invention relates to the technical field of optical waveguide devices, and discloses an optical waveguide sensor, a manufacturing method thereof and electronic equipment. Waveguide structures are arranged on the two sides of the silicon-based back plate; a double-slit grating structure is arranged in the middle area of the silicon-based backboard; the double-slit grating structure comprises two slits which extend along a first direction and are parallel to each other, and a plurality of gratings which extend along a second direction perpendicular to the first direction and are distributed periodically; a transition structure is arranged between the waveguide structure and the double-slit grating structure. According to the optical waveguide sensor, light in the optical fiber can be well coupled into the waveguide, the coupling efficiency is high, the sensitivity is high, the cost is low, integration with a circuit can be achieved, analysis and detection of an environmental medium are achieved through detection of an optical signal, and then the change of the temperature of a liquid cooling medium of equipment is monitored on the premise that high precision is kept.

Description

Technical Field

[0001] The present invention relates to the technical field of optical waveguide devices, and in particular to an optical waveguide sensor and a manufacturing method thereof, and electronic equipment. Background Art

[0002] With the development of optical waveguide devices in recent years, optical waveguide sensors have gradually been recognized by various industries and have become an advanced technology with important prospects in many applications, such as environmental protection, biomedicine, pharmaceutical production, etc. Due to the interaction between the evanescent wave of light and the medium to be measured on the surface of the device or in the environment, optical waveguide sensors are widely used in the field of sensing. However, traditional optical waveguide sensors have low sensitivity, low device integration, high cost, and little research on related matching couplers, and their applicability in the server field is poor. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide an optical waveguide sensor and a manufacturing method thereof, and an electronic device with high coupling efficiency, high sensitivity, low cost, and the ability to be integrated with a circuit to monitor changes in the temperature of a liquid-cooling medium of the device while maintaining high precision.

[0004] In order to solve the above technical problems, the present invention provides an optical waveguide sensor, comprising:

[0005] Silicon-based backplane;

[0006] Waveguide structures are arranged on both sides of the silicon-based backplane;

[0007] A double-slit grating structure is arranged in the middle area of ​​the silicon-based backplane; the double-slit grating structure includes two slits extending along a first direction and parallel to each other, and a plurality of gratings with periodic distribution extending along a second direction perpendicular to the first direction;

[0008] A transition structure is arranged between the waveguide structure and the double-slit grating structure.

[0009] In a first aspect, in the above optical waveguide sensor provided by the present invention, the transition structure comprises: a first coupling region adjacent to the waveguide structure;

[0010] The first coupling region is a tapered structure; a side of the first coupling region close to the waveguide structure is larger than the other side away from the waveguide structure.

[0011] On the other hand, in the above optical waveguide sensor provided by the present invention, the transition structure further comprises: a second coupling region adjacent to the first coupling region;

[0012] One end of the second coupling region close to the double-slit grating structure has two tapered groove structures;

[0013] The two tapered groove structures are butted against the two slits of the double-slit grating structure.

[0014] On the other hand, in the above optical waveguide sensor provided by the present invention, in the double-slit grating structure, the regions where the two slits and the multiple gratings are located constitute a first sub-region, a second sub-region, a third sub-region, a fourth sub-region and a fifth sub-region which are connected in sequence;

[0015] The first sub-region and the fifth sub-region are regions having only slits;

[0016] The second sub-region and the fourth sub-region are regions where two slits and a portion of the grating do not intersect;

[0017] The third sub-region is a region where the two slits intersect with another part of the grating.

[0018] On the other hand, in the above optical waveguide sensor provided by the present invention, the transition structure further comprises: a third coupling region adjacent to the second coupling region;

[0019] The third coupling region includes the first sub-region, the second sub-region, the fourth sub-region and the fifth sub-region.

[0020] On the other hand, in the above optical waveguide sensor provided by the present invention, the second sub-region and the fourth sub-region both include conical structures located on both sides of the slit and without gratings;

[0021] The inclined side walls of the conical structure in the second sub-region and the fourth sub-region are formed by a plurality of gratings with gradually increasing lengths in a direction approaching the third sub-region.

[0022] On the other hand, in the above optical waveguide sensor provided by the present invention, the ratio of the width of the waveguide structure to the second coupling region ranges from 12.57 to 17.99;

[0023] The width of the waveguide structure ranges from 12 μm to 17 μm;

[0024] The width of the second coupling region ranges from 945nm to 955nm;

[0025] The coupling length of the first coupling region ranges from 400 μm to 600 μm;

[0026] The length of the two tapered groove structures in the second coupling region ranges from 2 μm to 4 μm;

[0027] The total length of the second sub-region and the fourth sub-region in the third coupling region ranges from 4.75 μm to 4.85 μm;

[0028] The ratio between the coupling length of the first coupling region and the length of the two tapered groove structures in the second coupling region ranges from 100 to 300;

[0029] The ratio between the length of the two tapered groove structures in the second coupling region and the total length of the second sub-region and the fourth sub-region in the third coupling region is in the range of 0.41 to 0.84;

[0030] The angle of the tip of each tapered groove structure in the second coupling region ranges from 40 degrees to 50 degrees;

[0031] An angle between the inclined sidewall of the tapered structure and the slit in the second sub-region and the fourth sub-region is in a range of 8 degrees to 12 degrees.

[0032] On the other hand, in the above optical waveguide sensor provided by the present invention, the interior of the double-slit grating structure and a partial area of ​​the transition structure are filled with polyhexamethylene hydrochloride.

[0033] In order to solve the above technical problems, the present invention also provides a method for manufacturing an optical waveguide sensor, comprising:

[0034] forming a silicon-based backplane;

[0035] A waveguide structure is formed on both sides of the silicon-based backplane, and a double-slit grating structure is formed in the middle area; the double-slit grating structure includes two slits extending along a first direction and parallel to each other, and a plurality of gratings with periodic distribution extending along a second direction perpendicular to the first direction;

[0036] At the same time, a transition structure is formed between the waveguide structure and the double-slit grating structure.

[0037] In order to solve the above technical problem, the present invention further provides an electronic device, comprising the above optical waveguide sensor provided by the present invention.

[0038] It can be seen from the above technical scheme that an optical waveguide sensor provided by the present invention comprises: a silicon-based backplane; a waveguide structure is arranged on both sides of the silicon-based backplane; a double-slit grating structure is arranged in the middle area of ​​the silicon-based backplane; the double-slit grating structure comprises two slits extending along a first direction and parallel to each other, and a plurality of gratings with periodic distribution extending along a second direction perpendicular to the first direction; and a transition structure is arranged between the waveguide structure and the double-slit grating structure.

[0039] The beneficial effect of the present invention is that the above-mentioned optical waveguide sensor provided by the present invention has waveguide structures on both sides of the silicon-based backplane, and a double-slit grating structure is provided in the middle area of ​​the silicon-based backplane; a transition structure is provided between the waveguide structure and the double-slit grating structure; wherein the double-slit grating structure includes two slits, and a plurality of gratings that are perpendicular to the slits and have a periodic distribution. Such an optical waveguide sensor can couple the light in the optical fiber into the waveguide well, has high coupling efficiency, high sensitivity, low cost, and can be integrated with the circuit, and can realize the analysis and detection of the environmental medium by detecting the optical signal, thereby monitoring the temperature change of the liquid cooling medium of the equipment under the premise of maintaining high precision.

[0040] In addition, the present invention also provides a corresponding manufacturing method and electronic equipment for the optical waveguide sensor, which have the same or corresponding technical features as the above-mentioned optical waveguide sensor, further making the above-mentioned optical waveguide sensor more practical, and the manufacturing method and electronic equipment have corresponding advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 A schematic diagram of the structure of an optical waveguide sensor provided by an embodiment of the present invention;

[0043] Figure 2 A cross-sectional schematic diagram of an optical waveguide sensor provided by an embodiment of the present invention;

[0044] Figure 3 for Figure 2 Schematic diagram of corresponding color temperature;

[0045] Figure 4 A schematic diagram of a portion of the structure of an optical waveguide sensor provided by an embodiment of the present invention;

[0046] Figure 5 for Figure 4 A three-dimensional schematic diagram of the corresponding optical waveguide sensor;

[0047] Figure 6 A flow chart of a method for manufacturing an optical waveguide sensor provided by an embodiment of the present invention;

[0048] Figure 7 A schematic structural diagram corresponding to the process of manufacturing an optical waveguide sensor provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0049] Existing optical waveguide sensors have low sensitivity, low device integration, high cost, and little research on related matching couplers, and their applicability in the server field is poor. In order to solve this technical problem, the present invention provides an optical waveguide sensor that can well couple light in the optical fiber into the waveguide, has high sensitivity, low cost, and can be integrated with circuits to monitor changes in the temperature of the liquid cooling medium of equipment (such as servers).

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Figure 1 A schematic diagram of the structure of an optical waveguide sensor provided in an embodiment of the present invention is shown in FIG. Figure 1 As shown, the optical waveguide sensor comprises:

[0052] Silicon-based backplane;

[0053] A waveguide structure 1 is provided on both sides of the silicon-based backplane;

[0054] A double-slit grating structure 2 is arranged in the middle area of ​​the silicon-based back plate; the double-slit grating structure 2 includes two slits extending along a first direction and parallel to each other, and a plurality of gratings with periodic distribution extending along a second direction perpendicular to the first direction;

[0055] A transition structure is provided between the waveguide structure 1 and the double-slit grating structure 2 .

[0056] In the above optical waveguide sensor provided by the embodiment of the present invention, a waveguide structure 1 is provided on both sides of the silicon-based backplane, and a double-slit grating structure 2 is provided in the middle area of ​​the silicon-based backplane; a transition structure is provided between the waveguide structure 1 and the double-slit grating structure 2; wherein the double-slit grating structure 2 includes two slits, and a plurality of gratings that are perpendicular to the slits and have periodic distribution. Such an optical waveguide sensor can couple the light in the optical fiber into the waveguide well, has high coupling efficiency, high sensitivity, low cost, and can be integrated with the circuit, and can realize the analysis and detection of the environmental medium by detecting the optical signal, thereby monitoring the temperature change of the liquid cooling medium of the equipment under the premise of maintaining high precision.

[0057] It should be noted that the silicon-based backplane can adopt a silicon-on-insulator (SOI) structure. SOI refers to silicon on an insulating substrate. This structure introduces a buried oxide layer between the top silicon and the back substrate to achieve dielectric isolation of components in the integrated circuit, which can reduce parasitic capacitance and increase operating speed. The present invention can use silicon dioxide as a substrate and have a silicon thin film structure on the substrate. In other words, the overall structure of the optical waveguide sensor of the present invention can be designed as an SOI structure.

[0058] The waveguide structure 1 is a physical structure used to guide the propagation of electromagnetic waves, which can confine the electromagnetic waves inside and propagate in a specific direction, thereby reducing energy loss. The grating has a periodic structure, which refers to a specific geometric pattern arrangement with repetitiveness in the grating. In the present invention, it can be composed of a plurality of equally spaced and parallel grooves; this periodicity causes the grating to produce a specific optical effect related to the period when acting on the incident light. The above transition structure can be used for mode conversion.

[0059] In the process of manufacturing the above optical waveguide sensor provided by the embodiment of the present invention, a silicon-based backplane can be formed first; then, a waveguide structure 1 is formed on both sides of the silicon-based backplane, and a double-slit grating structure 2 is formed in the middle region; the double-slit grating structure 2 includes two slits extending in a first direction and parallel to each other, and a plurality of gratings with periodic distribution extending in a second direction perpendicular to the first direction. At the same time, a transition structure is formed between the waveguide structure 1 and the double-slit grating structure 2.

[0060] When the waveguide structure 1 is located on both sides of the silicon-based backplane arranged in the lateral direction, the two slits extend in the lateral direction and are parallel to each other, and the multiple gratings extend in the longitudinal direction and have a periodic distribution.

[0061] In implementation, the process of forming a silicon-based backplane may include: first, cleaning two polished silicon wafers with a thermal oxide layer of a set thickness grown on the surface; then, bonding the two cleaned silicon wafers using van der Waals forces in an ultra-clean environment, and performing annealing treatment; then, using one of the annealed silicon wafers as a substrate, grinding and polishing the other annealed silicon wafer to a target thickness, forming a silicon single crystal thin film on an insulator, to obtain a silicon-based backplane.

[0062] In addition, the process of forming the waveguide structure 1, the double slit grating structure 2, and the transition structure may include: spin coating photoresist on the surface of the silicon-based backplane and pre-baking; exposing the photoresist using a mask plate corresponding to the waveguide structure 1 pattern to be formed, the double slit grating structure 2 pattern to be formed, and the filter structure pattern to be formed; post-baking, developing and hardening the exposed photoresist; etching the sample obtained after hardening; removing the photoresist to obtain the waveguide structure 1, the double slit grating structure 2, and the transition structure.

[0063] The waveguide structure 1 can be introduced at both ends of the optical waveguide sensor by coupling with a wide waveguide; Figure 1 For example, the waveguide structure 1 can be rectangular, that is, a rectangular wide waveguide structure is introduced at both ends of the optical waveguide sensor. The most critical part of the optical waveguide sensor is the double slit grating structure 2, which is used for temperature sensing. If the waveguide structure 1 and the double slit grating structure 2 are directly connected together when designing the sensor, a very large mode mismatch loss will be introduced. Therefore, the present invention introduces a transition structure between the waveguide structure and the double slit grating structure. The transition structure can also be called a mode spot converter, which is used for low-loss switching between two modes.

[0064] Furthermore, in a specific implementation, in the above optical waveguide sensor provided by the embodiment of the present invention, the interior of the double-slit grating structure 2 and a partial area of ​​the transition structure are filled with polyhexamethylene hydrochloride (PHMB).

[0065] In practice, since the change in temperature will cause the change in the refractive index of the liquid-cooling medium of the device (such as a server), the change will in turn cause the change in the effective refractive index of the guided mode in the waveguide, thereby causing a change in the phase. Therefore, the optical waveguide sensor of the present invention takes the above factors into consideration, and polyhexamethylene hydrochloride PHMB can be filled in the interior of the double-slit grating structure 2 and in part of the transition structure. Polyhexamethylene hydrochloride PHMB can be used to detect slight changes in the refractive index, thereby further detecting changes in the temperature of the liquid-cooling medium of the device.

[0066] Figure 2 Schematic cross-sectional view of an optical waveguide sensor provided by an embodiment of the present invention. Figure 2 As shown, silicon dioxide is used as a substrate. After the silicon film on the surface of silicon dioxide is etched, polyhexamethylene hydrochloride PHMB 4 can be filled. A gas 5 (Gas), such as carbon tetrafluoride (CF 4 ). Figure 3 for Figure 2 The corresponding color temperature diagram, from Figure 3It can be seen that when the temperature of the liquid cooling medium of the equipment changes, the polarizability of PHMB will change, which will cause the refractive index of PHMB to change. The optical waveguide can detect this tiny change in the refractive index and infer the change in the temperature of the liquid cooling medium, thereby effectively realizing the function of temperature sensing.

[0067] Furthermore, in a specific implementation, in the above optical waveguide sensor provided in an embodiment of the present invention, if Figure 1 As shown, the transition structure may include: a first coupling region 31 adjacent to the waveguide structure 1 ; the first coupling region 31 may be a tapered structure; a side of the first coupling region 31 close to the waveguide structure 1 is larger than the other side away from the waveguide structure 1 .

[0068] In implementation, Figure 1 As shown, the first region of the transition structure is the first coupling region 31, which is a conical structure, one side is longer and the other side is shorter, the longer side corresponds to one side of the waveguide structure 1, and the shorter side is close to the double slit grating structure 2. The first coupling region 31 is arranged on both sides of the silicon-based backplane, that is, the optical waveguide sensor of the present invention can be composed of two first coupling regions 31, and the two first coupling regions 31 can be symmetrical structures or asymmetrical structures, which can be determined according to actual conditions. The most important thing in the coupling structure of the first coupling region 31 is the coupling length Ltp1. Only when the coupling length reaches a certain value can the loss of mode conversion be ignored.

[0069] Furthermore, in a specific implementation, in the above optical waveguide sensor provided in an embodiment of the present invention, if Figure 1 As shown, the transition structure may further include: a second coupling region 32 adjacent to the first coupling region 31; the second coupling region 32 has two tapered groove structures at one end close to the double-slit grating structure 2; and the two tapered groove structures are connected to the two slits of the double-slit grating structure 2.

[0070] In implementation, Figure 1As shown, the second region of the transition structure is the second coupling region 32. This region can be a rectangular structure or a structure of other shapes, which is not limited here. The width of the second coupling region 32 is the same as the width of the other side of the first coupling region 31 away from the waveguide structure 1, and the length of the second coupling region 32 can be unlimited. The second coupling region 32 is arranged on both sides of the silicon-based backplane, that is, the optical waveguide sensor of the present invention can be composed of two second coupling regions 32, and these two second coupling regions 32 can be symmetrical structures or asymmetrical structures, which can be determined according to actual conditions. The second coupling region 32 adopts the design of two tapered groove structures. These two tapered groove structures are the second coupling region 32 located at one end close to the double-slit grating structure 2, and the groove width at the end is consistent with the slit width. Although the length of the second coupling region can be unlimited, the length Ltp2 of the two tapered groove structures needs to be effectively adjusted, and the range can be from 2μm to 4μm, as long as the mode conversion loss is low.

[0071] Furthermore, in a specific implementation, in the above optical waveguide sensor provided in an embodiment of the present invention, if Figure 1 As shown, in the double-slit grating structure 2, the area where the two slits and the multiple gratings are located constitutes a first sub-area A, a second sub-area B, a third sub-area C, a fourth sub-area D and a fifth sub-area E which are connected in sequence; the first sub-area A and the fifth sub-area E are areas having only slits; the second sub-area B and the fourth sub-area D are areas where the two slits and a part of the grating do not intersect; the third sub-area C is an area where the two slits intersect with another part of the grating.

[0072] In implementation, Figure 1 As shown, in the double-slit grating structure 2, the area where the two slits and the multiple gratings are located can be divided into five sub-areas, namely the first sub-area A, the second sub-area B, the third sub-area C, the fourth sub-area D and the fifth sub-area E. Figure 1 It can be seen that the first sub-region A and the fifth sub-region E can be regions with only slits, that is, these sub-regions have only two horizontal slits; the second sub-region B and the fourth sub-region D can be regions where the two slits and a part of the grating do not intersect, that is, although these two sub-regions have slits and gratings, the slits and the gratings do not intersect; the third sub-region C can be a region where the two slits intersect with another part of the grating, that is, this sub-region not only has slits and gratings, but also the slits and the grating intersect.

[0073] Furthermore, in a specific implementation, in the above optical waveguide sensor provided in an embodiment of the present invention, if Figure 1 As shown, the transition structure may further include: a third coupling region 33 adjacent to the second coupling region 32; the third coupling region includes a first sub-region A, a second sub-region B, a fourth sub-region D and a fifth sub-region E.

[0074] In implementation, the second sub-region B and the fourth sub-region D may both include conical structures located on both sides of the slit and without gratings; the inclined side walls of the conical structures in the second sub-region B and the fourth sub-region D are formed by multiple gratings with gradually increasing lengths toward the direction approaching the third sub-region C.

[0075] Figure 4 A partial structural diagram of an optical waveguide sensor provided in an embodiment of the present invention. Figure 4 As shown, the third coupling region 33 is adjacent to the second coupling region 32, and the third coupling region 33 is between the double slit region and the double slit grating region, and the conical structure in the second sub-region B and the fourth sub-region D is used to realize the transition between the double slit region and the double slit grating region. Figure 5 for Figure 4 The corresponding three-dimensional schematic diagram of the optical waveguide sensor is as follows: Figure 5 As shown, the length Ltp3 of the tapered transition region may be an integer multiple of the grating period, that is, the length Ltp3 of the second sub-region B and the fourth sub-region D may both be an integer multiple of the grating period.

[0076] Further, in a specific implementation, the width W2 of the waveguide structure 1 may range from 12 μm to 17 μm, and the height H may range from 220 nm. The width of the first coupling region 31 on one side close to the waveguide structure 1 is equal to the width W2 of the waveguide structure 1, while the width W1 on the other side away from the waveguide structure 1 (i.e., the width of the second coupling region) may range from 945 nm to 955 nm. The ratio between the width W2 of the waveguide structure 1 and the width W1 of the second coupling region ranges from 12.57 to 17.99. The coupling length Ltp1 of the first coupling region 31 may range from 400 μm to 600 μm. The length Ltp2 of the two tapered groove structures in the second coupling region 32 may range from 2 μm to 4 μm. The length Ltp3 of the second sub-region B and the fourth sub-region D in the third coupling region may range from 4.75 μm to 4.85 μm. It should be noted that the width of each slit may be 100 nm. The grating period can be 480nm, the number of grating periods can be 40, and the duty cycle can be 0.5. The length Ltp3 of the second sub-region B and the fourth sub-region D can reach 10 grating period lengths. The ratio between the coupling length of the first coupling region and the length of the two tapered groove structures in the second coupling region ranges from 100 to 300; the ratio between the length of the two tapered groove structures in the second coupling region and the total length of the second sub-region and the fourth sub-region in the third coupling region ranges from 0.41 to 0.84; the angle of the tip of each tapered groove structure in the second coupling region ranges from 40 degrees to 50 degrees; the angle between the inclined side wall of the tapered structure and the slit in the second sub-region and the fourth sub-region ranges from 8 degrees to 12 degrees. Such a setting can obtain a better mode conversion effect, and compared with traditional optical waveguide sensors, it has high integration, low cost, and high sensitivity.

[0077] The optical waveguide sensor provided by the embodiment of the present invention is simulated and tested, for example, by using the Finite-Difference Time-Domain (FDTD) algorithm to simulate it. When the width W2 of the waveguide structure 1 is 15 μm, the width of the first coupling region 31 close to the waveguide structure 1 is 15 μm and the width W1 of the other side away from the waveguide structure 1 is 950 nm, the coupling length Ltp1 of the first coupling region 31 is 500 μm, the length Ltp2 of the two tapered groove structures in the second coupling region 32 is 3 μm, and the length Ltp3 of the second sub-region B and the fourth sub-region D is 4.8 μm, the mode conversion loss is less than 0.01% and can be ignored. The present invention can also use numerical simulation to further simulate the sensing performance of the optical waveguide sensor, and its sensitivity can reach 350 nm / RIU, and the detection limit is about 9x10 -4 RIU.

[0078] In the above embodiments, the optical waveguide sensor is described in detail. Based on the same inventive concept, the embodiments of the present invention also provide a method for manufacturing the optical waveguide sensor and corresponding embodiments of the electronic device.

[0079] Figure 6 Flow chart of the method for manufacturing an optical waveguide sensor provided in an embodiment of the present invention. The method for manufacturing an optical waveguide sensor provided in this embodiment, such as Figure 6 As shown, the specific steps include:

[0080] S601, forming a silicon-based backplane.

[0081] In a possible implementation, the silicon-based backplane refers to silicon on an insulating substrate. The structure introduces a buried oxide layer between the top silicon and the back substrate to achieve dielectric isolation of components in the integrated circuit, which can reduce parasitic capacitance and increase operating speed. The present invention can use silicon dioxide as a substrate to form a silicon thin film structure on the substrate.

[0082] S602, forming a waveguide structure on both sides of the silicon-based backplane, and forming a double-slit grating structure in the middle area; the double-slit grating structure includes two slits extending along a first direction and parallel to each other, and a plurality of gratings with periodic distribution extending along a second direction perpendicular to the first direction.

[0083] In a possible implementation, when the first direction is horizontal and the second direction is vertical, the waveguide structure 1 is located on both sides of the silicon-based backplane arranged in the horizontal direction, the two slits extend in the horizontal direction and are parallel to each other, and the multiple gratings extend in the vertical direction and have a periodic distribution. Conversely, when the first direction is vertical and the second direction is horizontal, the waveguide structure 1 is located on both sides of the silicon-based backplane arranged in the vertical direction, the two slits extend in the vertical direction and are parallel to each other, and the multiple gratings extend in the horizontal direction and have a periodic distribution. The waveguide structure can be introduced at both ends of the optical waveguide sensor by coupling of a wide waveguide; the waveguide structure can be rectangular, that is, a rectangular wide waveguide structure is introduced at both ends of the optical waveguide sensor. The double-slit grating structure is used for temperature sensing.

[0084] S603. At the same time, a transition structure is formed between the waveguide structure and the double-slit grating structure.

[0085] In a possible implementation, if the waveguide structure and the double-slit grating structure are directly connected together when designing the sensor, a very large mode mismatch loss will be introduced. Therefore, the present invention introduces a transition structure between the waveguide structure and the double-slit grating structure. The transition structure can also be called a mode spot converter, which is used for low-loss switching between the two modes.

[0086] In the manufacturing method of the above optical waveguide sensor provided in the embodiment of the present invention, by executing the above steps S601 to S603, a waveguide structure can be provided on both sides of the silicon-based backplane, and a double-slit grating structure can be provided in the middle area of ​​the silicon-based backplane; a transition structure can be provided between the waveguide structure and the double-slit grating structure; wherein the double-slit grating structure includes two slits, and a plurality of gratings that are perpendicular to the slits and have a periodic distribution. Such an optical waveguide sensor can couple the light in the optical fiber into the waveguide well, has high coupling efficiency, high sensitivity, low cost, and can be integrated with the circuit, and can realize the analysis and detection of the environmental medium by detecting the optical signal, thereby monitoring the temperature change of the liquid cooling medium of the equipment while maintaining high precision.

[0087] Since the embodiments of the manufacturing method part correspond to the embodiments of the optical waveguide sensor part, the embodiments of the manufacturing method part refer to the description of the embodiments of the optical waveguide sensor part, which will not be described here. And it has the same beneficial effects as the optical waveguide sensor mentioned above.

[0088] Furthermore, in a specific implementation, in the method for manufacturing the above-mentioned optical waveguide sensor provided in an embodiment of the present invention, in the process of executing step S601 to form a silicon-based backplane, it can specifically include: first, cleaning two polished silicon wafers with a thermal oxide layer of a set thickness grown on the surface; then, bonding the two cleaned silicon wafers using van der Waals forces in an ultra-clean environment, and annealing them; thereafter, using one of the annealed silicon wafers as a substrate, grinding and polishing the other annealed silicon wafer to a target thickness, forming a silicon single crystal thin film on an insulator, so as to obtain a silicon-based backplane.

[0089] In implementation, Figure 7 The following is a schematic diagram of the structure corresponding to the process of manufacturing an optical waveguide sensor provided by an embodiment of the present invention. Figure 7 As shown, two well-polished silicon wafers 6 with a 2μm high-quality thermal oxide layer grown on the surface are strictly cleaned, and then bonded by van der Waals force in an ultra-clean environment, and annealed at high temperature to improve the bonding strength. At this time, there is silicon dioxide 7 between the two silicon wafers 6. Next, one annealed silicon wafer is used as a substrate, and the other annealed silicon wafer is ground and polished to the required thickness to form a silicon single crystal film on an insulator to obtain a silicon-based backplane. Afterwards, the cleanliness of the surface of the silicon-based backplane can be ensured by ultrasonic cleaning or other methods.

[0090] Correspondingly, in the process of performing step S602 and step S603 to form the waveguide structure, the double slit grating structure, and the transition structure, as shown in FIG. Figure 7As shown, the process may specifically include: spin coating photoresist 8 on the surface of the silicon-based backplane, and performing soft baking; using a mask plate corresponding to the waveguide structure pattern to be formed, the double-slit grating structure pattern to be formed, and the filter structure pattern to be formed, the photoresist is exposed (Expose), wherein ultraviolet light 9 (UV-Light) may be used; the exposed photoresist is post-baked (Post Exposure Bake), developed (Develop) and hard-baked (Hard Bake); the sample obtained after hardening is etched (Etch), wherein carbon tetrafluoride (CF 4 ) 5 gas; remove the photoresist (Strip) to obtain the waveguide structure, double slit grating structure, and transition structure.

[0091] Furthermore, in a specific implementation, the method for manufacturing the optical waveguide sensor provided in the embodiment of the present invention may further include: filling poly(hexamethylene hydrochloride) (PHMB) in the interior of the double-slit grating structure and in a partial area of ​​the transition structure.

[0092] In implementation, Figure 7 As shown, polyhexamethylene hydrochloride PHMB 4 (Coat and Cure PHMB) is spin-coated inside the double-slit grating structure and in part of the transition structure, and excess polyhexamethylene hydrochloride PHMB (Remove excess PHMB) is removed using a microcontroller system and water to obtain the desired optical waveguide sensor.

[0093] Furthermore, in a specific implementation, in the method for manufacturing the above-mentioned optical waveguide sensor provided in an embodiment of the present invention, in the process of forming a double-slit grating structure, it can specifically include: forming a first sub-region, a second sub-region, a third sub-region, a fourth sub-region and a fifth sub-region connected in sequence in the region where two slits and multiple gratings are formed; the first sub-region and the fifth sub-region are regions having only slits; the second sub-region and the fourth sub-region are regions where the two slits and a portion of the grating do not intersect; the third sub-region is a region where the two slits intersect with another portion of the grating.

[0094] Furthermore, in the specific implementation, in the manufacturing method of the optical waveguide sensor provided in the embodiment of the present invention, in the process of forming the transition structure, it can specifically include: forming a first coupling region adjacent to the waveguide structure; the first coupling region can be a tapered structure; the side of the first coupling region close to the waveguide structure is larger than the other side away from the waveguide structure; forming a second coupling region adjacent to the first coupling region; the second coupling region has two tapered groove structures at one end close to the double-slit grating structure; the two tapered groove structures are connected to the two slits of the double-slit grating structure; forming a third coupling region adjacent to the second coupling region; the third coupling region includes a first sub-region, a second sub-region, a fourth sub-region and a fifth sub-region. Wherein, the second sub-region and the fourth sub-region both include tapered structures located on both sides of the slit and without gratings; the inclined sidewalls of the tapered structures in the second sub-region and the fourth sub-region are formed by a plurality of gratings with gradually increasing lengths in the direction close to the third sub-region.

[0095] Furthermore, in a specific implementation, the method for manufacturing the optical waveguide sensor provided in the embodiment of the present invention may also include: integrating the optical waveguide sensor with a circuit in a device mainboard, collecting data in real time, and uploading the data to the device to achieve real-time monitoring of high-precision temperature.

[0096] In practice, the present invention can integrate the manufactured optical waveguide sensor with the circuit in the server mainboard, collect data in real time, and upload the data to the server system to realize real-time monitoring of high-precision temperature.

[0097] For more specific working processes of the above steps, please refer to the corresponding contents disclosed in the above embodiments, which will not be repeated here.

[0098] Based on the same inventive concept, an embodiment of the present invention further provides an electronic device, including the above optical waveguide sensor. Since the principle of solving the problem by the electronic device is similar to that of the above optical waveguide sensor, the implementation of the electronic device can refer to the implementation of the optical waveguide sensor, and the repeated parts will not be repeated.

[0099] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0100] In summary, an optical waveguide sensor and a manufacturing method thereof, and an electronic device provided by an embodiment of the present invention include: a silicon-based backplane; a waveguide structure is provided on both sides of the silicon-based backplane; a double-slit grating structure is provided in the middle area of ​​the silicon-based backplane; the double-slit grating structure includes two slits extending in a first direction and parallel to each other, and a plurality of gratings with periodic distribution extending in a second direction perpendicular to the first direction; a transition structure is provided between the waveguide structure and the double-slit grating structure. In this way, through the combination of the waveguide structure, the transition structure and the double-slit grating structure, the light in the optical fiber can be well coupled into the waveguide, with high coupling efficiency, high sensitivity, low cost, and can be integrated with the circuit, and the analysis and detection of the environmental medium can be realized by detecting the optical signal, thereby monitoring the temperature change of the liquid cooling medium of the equipment while maintaining high precision.

[0101] Finally, it should be noted that, unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by technicians in the technical field of the present application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include", "comprise" and "have" and any other variations thereof in the present application are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the elements. In the present application, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0102] For the above-mentioned embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the order of the actions described, because according to the present invention, some steps may be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0103] Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on these embodiments, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in this field can still combine, add, delete or make other adjustments to the features in the embodiments of the present invention according to the circumstances without conflict and without making creative work, so as to obtain different other technical solutions that do not deviate from the concept of the present invention in essence, and these technical solutions also belong to the scope of protection of the present invention.

[0104] The optical waveguide sensor and its manufacturing method and electronic device provided by the present invention are introduced in detail above. Specific examples are used in this article to illustrate the principle and implementation of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention, but not to limit the protection scope of the invention; at the same time, for ordinary technicians in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An optical waveguide sensor, characterized in that: include: Silicon-based backplane; Waveguide structures are arranged on both sides of the silicon-based backplane; A double-slit grating structure is provided in the middle area of ​​the silicon-based backplane; The double-slit grating structure includes two slits extending along a first direction and parallel to each other, and a plurality of gratings with periodic distribution extending along a second direction perpendicular to the first direction; A transition structure is arranged between the waveguide structure and the double-slit grating structure.

2. The optical waveguide sensor according to claim 1, characterized in that: The transition structure includes: a first coupling region adjacent to the waveguide structure; The first coupling region is a tapered structure; a side of the first coupling region close to the waveguide structure is larger than the other side away from the waveguide structure.

3. The optical waveguide sensor according to claim 2, characterized in that: The transition structure further includes: a second coupling region adjacent to the first coupling region; One end of the second coupling region close to the double-slit grating structure has two tapered groove structures; The two tapered groove structures are butted against the two slits of the double-slit grating structure.

4. The optical waveguide sensor according to claim 3, characterized in that: In the double-slit grating structure, the regions where the two slits and the multiple gratings are located constitute a first sub-region, a second sub-region, a third sub-region, a fourth sub-region and a fifth sub-region which are connected in sequence; The first sub-region and the fifth sub-region are regions having only slits; The second sub-region and the fourth sub-region are regions where two slits and a portion of the grating do not intersect; The third sub-region is a region where the two slits intersect with another part of the grating.

5. The optical waveguide sensor according to claim 4, characterized in that: The transition structure further includes: a third coupling region adjacent to the second coupling region; The third coupling region includes the first sub-region, the second sub-region, the fourth sub-region and the fifth sub-region.

6. The optical waveguide sensor according to claim 5, characterized in that The second sub-region and the fourth sub-region both include conical structures located on both sides of the slit and without gratings; The inclined side walls of the conical structure in the second sub-region and the fourth sub-region are formed by a plurality of gratings with gradually increasing lengths in a direction approaching the third sub-region.

7. The optical waveguide sensor according to claim 6, characterized in that The ratio of the width of the waveguide structure to the second coupling region ranges from 12.57 to 17.99; The width of the waveguide structure ranges from 12 μm to 17 μm; The width of the second coupling region ranges from 945nm to 955nm; The coupling length of the first coupling region ranges from 400 μm to 600 μm; The length of the two tapered groove structures in the second coupling region ranges from 2 μm to 4 μm; The total length of the second sub-region and the fourth sub-region in the third coupling region ranges from 4.75 μm to 4.85 μm; The ratio between the coupling length of the first coupling region and the length of the two tapered groove structures in the second coupling region ranges from 100 to 300; The ratio between the length of the two tapered groove structures in the second coupling region and the total length of the second sub-region and the fourth sub-region in the third coupling region is in the range of 0.41 to 0.84; The angle of the tip of each tapered groove structure in the second coupling region ranges from 40 degrees to 50 degrees; An angle between the inclined sidewall of the tapered structure and the slit in the second sub-region and the fourth sub-region is in a range of 8 degrees to 12 degrees.

8. The optical waveguide sensor according to claim 1, characterized in that: The interior of the double-slit grating structure and a partial region of the transition structure are filled with polyhexamethylene hydrochloric acid.

9. A method for manufacturing an optical waveguide sensor, characterized in that: include: forming a silicon-based backplane; A waveguide structure is formed on both sides of the silicon-based backplane, and a double-slit grating structure is formed in the middle area; The double-slit grating structure includes two slits extending along a first direction and parallel to each other, and a plurality of gratings with periodic distribution extending along a second direction perpendicular to the first direction; At the same time, a transition structure is formed between the waveguide structure and the double-slit grating structure.

10. An electronic device, characterized in that: Comprising the optical waveguide sensor according to any one of claims 1 to 8.

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