Optical inertial sensor and forming method thereof

Abstract

The invention discloses an optical inertial sensor and a forming method thereof, the optical inertial sensor comprises a plurality of stacked optical waveguide layers, and each optical waveguide layer comprises a substrate and at least one optical waveguide sub-path arranged in the substrate; and the optical waveguide sub-channels in the plurality of stacked optical waveguide layers are communicated with one another to form an optical waveguide channel. The method can improve the performance of the optical inertial sensor.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to an optical inertial sensor and a method for forming the same. Background Art

[0002] Existing laser fiber inertial navigation systems require coaxially winding optical fibers (made of SiO2) several kilometers or tens of kilometers long, which is complex in process, large in diameter, large in volume, high in power and high in cost. Monolithic silicon-based optical waveguide laser fiber inertial navigation sensors, due to limited area (maximum 256x320mm), can only construct optical waveguides between 100 and 200 meters in length, which cannot be long enough to produce sufficient inertial optical effects.

[0003] How to increase the length of the optical waveguide while reducing the volume of the fiber optic inertial navigation sensor to improve performance is a problem that needs to be solved urgently. Summary of the invention

[0004] The present invention provides an optical inertial sensor and a method for forming the same to improve the performance of the optical inertial transducer.

[0005] The present invention provides an optical inertial sensor, comprising: a plurality of stacked optical waveguide layers, each optical waveguide layer comprising a substrate and at least one optical waveguide sub-path arranged in the substrate; the optical waveguide sub-paths in the plurality of stacked optical waveguide layers are interconnected to form an optical waveguide path.

[0006] Optionally, the optical waveguide sub-path includes: an optical waveguide line, a beam introduction joint and a beam output joint connected at both ends of the optical waveguide line; the beam introduction joint and the beam output joint of adjacent optical waveguide layers are optically aligned and connected.

[0007] Optionally, it also includes: a light sensor and a light importer, which are respectively arranged on both sides of the plurality of stacked optical waveguide layers, the light incident end of the light sensor is opposite to the light outlet of the light beam lead-out connector of the corresponding optical waveguide layer, and the light output end of the light importer is opposite to the light incident port of the light beam lead-in connector of the corresponding optical waveguide layer.

[0008] Optionally, the optical waveguide sub-channel is filled with a light-guiding medium.

[0009] Optionally, the light-guiding medium is silicon dioxide;

[0010] Optionally, a light reflecting layer is formed on the inner wall of the optical waveguide sub-channel.

[0011] Optionally, the light reflection layer includes an import reflection plate located on the inner wall of the import joint, and an export reflection plate located on the inner wall of the light beam export joint, and the import reflection plate and the export reflection plate form an angle of 30 to 70 degrees with the substrate plane.

[0012] Optionally, the light reflecting layer includes a metal layer.

[0013] Optionally, the substrate is a semiconductor layer, and the optical waveguide sub-pipelines are all formed by a semiconductor process.

[0014] Optionally, the length direction of the optical waveguide sub-pipeline extends within the plane of the substrate, and the openings of the light beam introduction joint and the light beam output joint are respectively located at the opposite first surface and second surface of the substrate.

[0015] The present application also provides a method for forming an optical inertial sensor, which is characterized by comprising: forming an optical waveguide layer, wherein the optical waveguide layer comprises: a substrate and at least one optical waveguide sub-path arranged in the substrate; stacking and connecting a plurality of optical waveguide layers so that the optical waveguide sub-paths in each optical waveguide layer are connected to form an optical waveguide path.

[0016] Optionally, the method for forming the optical waveguide sub-path includes: forming an optical waveguide line in the substrate, and a beam introduction connector and a beam output connector respectively located at two ends of the optical waveguide line; and stacking and connecting a plurality of optical waveguide layers includes: optically aligning and connecting the beam introduction connectors and beam output connectors of adjacent optical waveguide layers.

[0017] Optionally, the method for forming the optical waveguide layer includes: providing a substrate, the substrate including a first surface and a second surface opposite to each other; forming a first groove on the first surface of the substrate; forming a second groove on the first surface of the substrate, the second groove is located at one end of the first groove and connected to the first groove; and the second groove has an inclined side wall on one side, so that the opening size of the second groove is larger than the bottom size; forming a third groove on the second surface of the substrate, the third groove is located at the other end of the first groove and connected to the first groove, and the third groove has an inclined side wall on one side, so that the opening size of the third groove is larger than the bottom size; and also includes: filling a light guiding medium in the first groove, the second groove and the third groove.

[0018] Optionally, before forming the second groove, a light-guiding medium is filled in the first groove; before forming the third groove, a light-guiding medium is filled in the second groove.

[0019] Optionally, a light reflecting layer is formed on the inner wall surface of each groove.

[0020] Optionally, the method for forming the light reflecting layer includes: after forming the first groove, forming a first light reflecting material layer covering the inner wall of the first groove; after forming the second groove, forming a second reflecting material layer on the inner wall surface of the second groove, and one side wall of the second groove exposes the first light reflecting material layer at the end of the first groove; after filling the optical waveguide medium in the second groove, removing the first reflecting material layer and the second reflecting material layer between the second groove and the first groove; forming a third light reflecting material layer covering the surface of the optical waveguide medium in the first groove; after forming the third groove, forming the third reflecting material layer on the inner wall surface of the third groove, and one side wall of the third groove exposes the first light reflecting material layer at the other end of the first groove; after filling the optical waveguide medium in the third groove, removing the first reflecting material layer and the fourth reflecting material layer between the third groove and the first groove.

[0021] Optionally, before forming the third groove, the first surface of the substrate is fixed to a carrier surface, and the second surface of the substrate is thinned.

[0022] Optionally, the plurality of optical waveguide layers are bonded and connected via a bonding layer.

[0023] The optical inertial sensor provided by the present invention can form a coaxial surrounding optical waveguide wire with a relatively long length by bonding multiple optical waveguide layers, thereby realizing the physical configuration of a traditional laser optical fiber, that is, a full laser light guider and a laser signal sensor, that is, it can realize the same function of the entire laser optical fiber inertial navigation, and has the advantages of small size, controllable process, high precision, low power consumption, and controllable overall cost.

[0024] Furthermore, the optical inertial sensor can be used for a laser fiber inertial navigation sensor, which is composed of a plurality of mutually (one-to-one) bonded silicon-based optical waveguide plane laser sensors and a laser light source introducer, wherein each silicon-based optical waveguide plane contains at least one optical waveguide line made of silicon dioxide, and a beam introduction joint and a beam output joint connected to both ends thereof. Compared with traditional technical solutions and products, this laser fiber inertial navigation sensor has the advantages of small size, low power consumption, low cost, and even high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1is a schematic flow chart of a method for forming an optical inertial sensor in one embodiment of the present application;

[0027] Figures 2 to 12 is a structural schematic diagram of a formation process of an optical inertial sensor according to an embodiment of the present application;

[0028] Fig.13 Schematic diagram of the structure of the optical inertial sensor according to an embodiment of the present application. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application are clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application. In the absence of conflict, the following embodiments and their technical features can be combined with each other.

[0030] The present invention will be described more clearly and completely below through embodiments in conjunction with the accompanying drawings.

[0031] Please refer to Figure 1 FIG. 4 is a schematic flow chart of a process of forming a fiber optic inertial sensor according to an embodiment of the present invention.

[0032] In this embodiment, the method for forming the optical inertial sensor includes the following steps:

[0033] Step S101: forming an optical waveguide layer, wherein the optical waveguide layer comprises: a substrate and at least one optical waveguide sub-channel arranged in the substrate.

[0034] The substrate may be a semiconductor substrate, such as a single crystal silicon substrate, a germanium silicon substrate, etc. An optical waveguide sub-path may be formed in the substrate through a semiconductor process, such as etching, filling, planarization, etc. The optical waveguide sub-path is used to provide a propagation path for light, and the light is totally reflected on the inner wall surface of the optical waveguide sub-path, so that the light can propagate in the path with very low loss.

[0035] In some embodiments, the method for forming the optical waveguide layer includes: forming an optical waveguide line in the substrate; and then forming a light beam introduction joint and a light beam output joint respectively located at both ends of the optical waveguide line. The optical waveguide line is the main transmission path of the light, and the light beam introduction joint is used to receive external incident light and guide the light into the optical waveguide line; the light beam output joint is used to guide the light in the optical waveguide line to the outside.

[0036] The optical waveguide line can be in various shapes such as a straight line or a spiral shape, so as to increase the length of the optical waveguide line as much as possible and increase the length of the waveguide path of the light.

[0037] Step S102: stacking and connecting a plurality of optical waveguide layers so that the optical waveguide sub-paths in each optical waveguide layer are connected to form an optical waveguide path.

[0038] The stacking and connecting of the plurality of optical waveguide layers includes: optically aligning and connecting the light beam introduction joints and light beam output joints of the optical waveguide layers of adjacent layers. The light beam introduced into the upper layer is emitted through the light beam output joint of the optical waveguide sub-pathway of the upper layer, enters the light beam introduction joint of the optical waveguide layer of the lower layer, enters the optical waveguide sub-pathway of the layer, and then is transmitted to the lower layer through the light beam output joint of the layer.

[0039] The optical waveguide sub-paths in the multi-layer optical waveguide layer are connected to form a longer wide waveguide path. By stacking the multi-layer optical waveguide layers, a longer optical waveguide line can be formed.

[0040] In some embodiments, the optical waveguide sub-paths in each optical waveguide layer are coaxially arranged to form a coaxial surrounding optical waveguide line with a relatively long length, thereby improving the optical inertial sensing performance.

[0041] In some embodiments, in step S101, the method for forming the optical waveguide layer specifically includes: providing a substrate, the substrate including a first surface and a second surface opposite to each other; forming a first groove on the first surface of the substrate; forming a second groove on the first surface of the substrate, the second groove is located at one end of the first groove and connected to the first groove; and the second groove has an inclined side wall on one side, so that the opening size of the second groove is larger than the bottom size; forming a third groove on the second surface of the substrate, the third groove is located at the other end of the first groove and connected to the first groove, and the third groove has an inclined side wall on one side, so that the opening size of the third groove is larger than the bottom size.

[0042] In some embodiments, the first groove, the second groove and the third groove may be filled with a light-guiding medium as an optical fiber transmission medium. The light-guiding medium is usually made of a transparent material, preferably a common semiconductor material, such as SiO 2 In other embodiments, the light-guiding medium may not be additionally filled, but air may be used as the light-guiding medium, and the optical waveguide sub-channel may be evacuated to increase the light transmission rate.

[0043] In some embodiments, specifically, before forming the second groove, a light-guiding medium is filled in the first groove; before forming the third groove, a light-guiding medium is filled in the second groove.

[0044] Furthermore, in some embodiments, a light reflection layer is formed on the inner wall surface of each groove to improve the reflection effect of the side wall of the light transmission path on the light and reduce the loss of light during the transmission process. Preferably, the material of the light reflection layer can be selected from metal materials, such as Cu, Al, W, Ag, etc., which have a high reflectivity to light and can be formed by semiconductor processes, such as sputtering, evaporation, etc. In other embodiments, the reflection layer can also be formed by selecting appropriate materials and processes according to actual needs.

[0045] Further, in some embodiments, the method for forming the light reflecting layer includes: after forming the first groove, forming a first light reflecting material layer covering the inner wall of the first groove; after forming the second groove, forming a second reflecting material layer on the inner wall surface of the second groove, and one side wall of the second groove exposes the first light reflecting material layer at the end of the first groove; after filling the optical waveguide medium in the second groove, removing the first reflecting material layer and the second reflecting material layer between the second groove and the first groove; forming a third light reflecting material layer covering the surface of the optical waveguide medium in the first groove; after forming the third groove, forming a fourth reflecting material layer on the inner wall surface of the third groove, and one side wall of the third groove exposes the first light reflecting material layer at the other end of the first groove; after filling the optical waveguide medium in the third groove, removing the first reflecting material layer and the fourth reflecting material layer between the third groove and the first groove.

[0046] Please refer to Figures 2 to 12 , is a structural schematic diagram of the formation process of the optical fiber inertial sensor of one embodiment of the present application.

[0047] Please refer to Figure 2 , a substrate 100 is provided, wherein the substrate 100 includes a first surface 101 and a second surface 102 opposite to each other.

[0048] The substrate 100 is a semiconductor layer. Preferably, in this embodiment, the substrate 100 is a single crystal silicon substrate.

[0049] Please refer to Figure 3a A first groove 201 is formed on the first surface 101 of the substrate 100 .

[0050] The first groove 201 is formed on the first surface 101 of the substrate 100 by an etching process. Specifically, the etching process adopts an anisotropic dry etching process, after forming a patterned photoresist layer on the surface of the substrate 101, the first substrate 100 is etched using the photoresist layer as a mask to form the first groove 201 of a certain depth.

[0051] The first groove 201 will subsequently serve as a main optical waveguide path in the optical waveguide sub-path to be formed. Therefore, the first groove 201 of a corresponding shape can be formed according to the path design of the optical waveguide sub-path.

[0052] The first groove 201 can be in a straight line shape, a curved line shape, etc.

[0053] In some embodiments, in order to increase the path length of the optical waveguide sub-path formed in the single-layer substrate, a spiral first groove 201 may be formed in the substrate 100 (see Figure 3b , with lines representing grooves), or a zigzag first groove (see Figure 3c , with lines representing the grooves), so as to increase the length of the first groove 201.

[0054] In order to further improve the total reflection effect of the inner wall of the first groove on light, a first groove 201 with an arc-shaped inner wall can be formed. After the first groove 201 is formed by dry etching, the inner wall of the first groove 201 is processed by one or more combinations of annealing, wet etching, gas etching, forming an ion doping layer and then etching and removing the inner wall of the first groove 201 to form an arc-shaped side wall and / or an arc-shaped inner wall, or the top corners of the bottom and top of the first groove are rounded.

[0055] In order to improve the light reflection effect of the inner wall of the optical waveguide sub-path, in this embodiment, a light reflection layer is also formed on the inner wall surface of the first groove 201 and other grooves formed subsequently.

[0056] Please refer to Figure 4 After forming the first groove 201 , a first light reflecting material layer 301 is formed to cover the inner wall of the first groove 201 .

[0057] The first light reflecting material layer 301 can be made of a metal material with high reflectivity to light, such as Al, W, Cu, etc., and can be formed by a physical deposition process, such as sputtering, evaporation, etc., to cover the sidewalls and bottom surface of the first groove 201.

[0058] In this step, the first light reflecting material layer 301 also covers the first surface 101 of the substrate 100 at the same time.

[0059] In other embodiments, the first light reflecting material layer 301 may also be made of other types of light reflecting materials, such as an organic light reflecting layer.

[0060] Please refer to Figure 5 , a light guiding medium 401 is filled in the first groove 201 .

[0061] The deposition process is used to fill the light-guiding medium 401 in the first groove 201. In order to reduce energy loss during light propagation, the light-guiding medium 302 is made of a transparent material and is easy to be filled by a semiconductor process. Preferably, the light-guiding medium 401 is silicon dioxide.

[0062] In other embodiments, the light-guiding medium 401 may also be other light-transmitting materials, such as transparent polymer colloid materials. The transparent polymer colloid material is filled in the first groove 201 by a spin coating process and then cured to form the light-guiding medium 401 .

[0063] In other embodiments, the first groove 201 does not need to be filled, and the air in the groove can be directly used as a light-guiding medium. The optical waveguide can even be evacuated after the entire sensor is formed.

[0064] After the light guide medium 401 is filled, a planarization process is further performed to remove the first light reflective material and the light waveguide medium material covering the first surface 101 of the substrate 100 through chemical mechanical polishing or other suitable planarization processes, thereby exposing the first surface 101 of the substrate 100 .

[0065] Please refer to Figure 6 A second groove 202 is formed on the first surface 101 of the substrate 100 .

[0066] The second groove 202 is located at one end of the first groove 201 and is connected to the first groove. The connection means that the side wall of the first groove 201 is connected to the side wall of the second groove 202, and the bottom is connected to the bottom, so that the first groove 201 and the second groove 202 are connected, and light can be transmitted in the first groove 201 and the second groove 202.

[0067] One sidewall of the second groove 202 exposes the first light reflecting material layer at an end of the first groove.

[0068] The second groove 202 is used to form a light beam import / export connector of the optical waveguide sub-path, which has the function of changing the direction of the incident / outgoing light beams, for example, changing the direction of the light perpendicularly incident to the substrate to be transmitted in a direction parallel to the first substrate, so that it can enter the optical waveguide line formed by the first groove.

[0069] In order to change the direction of the light beam, the second groove has an inclined side wall on one side so that the opening size of the second groove 202 is larger than the bottom size; the inclined side wall faces the opening direction of the second groove 202 to face the incident direction of external light or the emitting direction of internal light.

[0070] Preferably, the inclined side wall forms an angle of 30 to 70 degrees with the plane of the substrate 100, which is conducive to adjusting the propagation direction of the light beam incident toward the substrate 100 to be along the surface direction of the substrate 100 after reflection by the inclined side wall, so as to enter the optical waveguide line formed by the first groove 201; or, adjusting the light beam transmitted along the optical waveguide line to be emitted toward the outside of the substrate 100 after reflection by the inclined side wall.

[0071] Please refer to Figure 7 After the second groove 202 is formed, a second reflective material layer 302 is formed on the inner wall surface of the second groove 202 ; and an optical waveguide medium 401 is filled in the second groove 202 .

[0072] The second light reflecting material layer 302 can be made of a metal material with high reflectivity to light, such as Al, W, Cu, etc., and can be formed by a physical deposition process, such as sputtering, evaporation, etc., to cover the sidewalls and bottom surface of the second groove 202.

[0073] In this embodiment, the second light reflecting material layer 302 may be formed by using the same material and process as the first light reflecting material layer 301 .

[0074] The second groove 202 is filled with the same optical waveguide medium 401 as that in the first groove 201 , and planarization is performed so that the surface of the optical waveguide medium 401 is flush with the first surface 101 of the substrate 101 .

[0075] Please refer to Figure 8 , remove the first reflective material layer 301 and the second reflective material layer 302 between the second groove 202 and the first groove 201 ; and form a third light reflective material layer 303 covering the surface of the optical waveguide medium 401 in the first groove 201 .

[0076] The first surface 101 exposes the first reflective material layer 301 and the second reflective material layer 302 isolated between the first groove 201 and the second groove 202; the first reflective material layer 301 and the second reflective material layer 302 between the first groove 201 and the second groove 202 are removed by a selective etching process, such as chemical etching.

[0077] After removing the first reflective material layer 301 and the second reflective material layer 302 between the first groove 201 and the second groove 202, annealing or the like may be further performed to allow the optical waveguide medium 401 to fill the gap between the first groove 201 and the second groove 202 generated by removing the first reflective material layer 301 and the second reflective material layer 302.

[0078] It is also possible that no additional processing is required, and the gap can be filled in a subsequent process such as forming a bonding layer.

[0079] The third light reflecting material layer 303 can be made of a metal material with high reflectivity to light, such as Al, W, Cu, etc., and can be formed by a physical deposition process, such as sputtering, evaporation, etc., to cover the first surface 101. Then, the third light reflecting material layer 303 is patterned to expose the light-guiding medium in the second groove 202, and the light-guiding medium in the first groove 201 is covered, and connected to the first light reflecting material layer 301 on the side wall and bottom of the first groove 201, so as to form a tube wall reflection layer surrounding the inner wall of the optical waveguide line, so as to prevent the light from being refracted to the outside of the optical waveguide line when transmitting in the optical waveguide line.

[0080] Please refer to Fig. 9 , fixing the first surface 101 of the substrate 101 on a surface of a carrier 500 .

[0081] The first surface 101 side of the substrate 101 faces the carrier 500 and is fixed to the surface of the carrier 500. The fixing can be done by bonding, forming a bonding layer 501 on the first surface 101 of the substrate 101 and / or the surface of the carrier 500 in advance, and fixing the substrate 101 and the carrier 500 to each other through the bonding layer 501.

[0082] Preferably, the bonding layer 501 is formed on the first surface 101 , and the bonding layer covers the first surface 101 and the third light reflecting material layer 303 located on the first surface 101 .

[0083] The bonding layer 501 is made of a light-guiding medium, preferably, the same material as the optical waveguide medium 401, that is, silicon dioxide. In the process of forming the bonding layer 501, the bonding layer 501 can also fill the gap between the optical waveguide medium 401 in the first groove 201 and the second groove 202 formed in the previous process.

[0084] After the first surface 101 of the substrate 101 is fixed on the carrier 500 , the second surface 102 faces outward, which facilitates subsequent processing of the second surface 102 .

[0085] Please refer to Fig.10 , the second surface 102 side of the substrate 100 is thinned.

[0086] The first reflective material layer 301 is used as a stop layer until the first reflective material layer 301 is exposed.

[0087] Please refer to Fig.11A third groove is formed on the second surface 102 of the substrate 100, and a fourth reflective material layer 304 is formed on the inner wall surface of the third groove. A light guiding medium 401 is filled in the third groove.

[0088] The third groove is located at the other end of the first groove 201 and is connected to the first groove 201. The third groove has an inclined side wall on one side, so that the opening size of the third groove is larger than the bottom size. The connection means that the side wall of the first groove 201 is connected to the side wall of the third groove, and the bottom is connected to the bottom, so that the first groove 201 and the third groove are connected, and light can be transmitted in the first groove 201 and the third groove.

[0089] One side wall of the third groove exposes the first light reflecting material layer at the end of the first groove. The third groove is used to form a light beam introduction / exit joint of the optical waveguide sub-path, and has the function of changing the direction of the incident / outgoing light beams, for example, changing the direction of the light beam vertically incident on the substrate to be transmitted in a parallel direction along the first substrate, so that the light beam can enter the optical waveguide line formed by the first groove.

[0090] In order to change the direction of the light beam, the third groove has an inclined side wall on one side so that the opening size of the third groove is larger than the bottom size; the inclined side wall faces the opening direction of the third groove to face the incident direction of external light or the emitting direction of internal light.

[0091] Preferably, the inclined side wall forms an angle of 30 to 70 degrees with the plane of the substrate 100, which is conducive to adjusting the propagation direction of the light beam incident toward the substrate 100 to be along the surface direction of the substrate 100 after reflection by the inclined side wall, so as to enter the optical waveguide line formed by the third groove 203; or, adjusting the light beam transmitted along the optical waveguide line to be emitted toward the outside of the substrate 100 after reflection by the inclined side wall.

[0092] One sidewall of the third groove exposes the first light reflecting material layer 301 at the other end of the first groove.

[0093] The fourth light reflecting material layer 304 can be made of a metal material with high reflectivity to light, such as Al, W, Cu, etc., and can be formed by a physical deposition process, such as sputtering, evaporation, etc., to cover the sidewalls and bottom surface of the third groove.

[0094] In this embodiment, the fourth light reflecting material layer 303 may be formed by using the same material and process as the second light reflecting material layer 302 .

[0095] Similarly, the third groove is filled with the same optical waveguide medium 401 as that in the first groove, and through planarization, the surface of the optical waveguide medium 401 is flush with the surface of the first reflective material layer 301 at the second surface 102 of the substrate 101. The first reflective material layer 301 and the fourth reflective material layer 304 isolated between the first groove 201 and the third groove 203 are exposed on the second surface 102; the first reflective material layer 301 and the fourth reflective material layer 304 located between the first groove 201 and the third groove 203 are removed through a selective etching process, such as chemical etching.

[0096] The method further includes removing the first reflective material layer 301 and the fourth reflective material layer 304 located between the third groove and the first groove.

[0097] After removing the first reflective material layer 301 and the fourth reflective material layer 304 between the third groove and the first groove 201 , annealing or the like may be further performed to allow the optical waveguide medium 401 to fill the gap generated by the above process.

[0098] It is also possible that no additional processing is required, and the gap can be filled in a subsequent process such as forming a bonding layer.

[0099] Through the above parts, an optical waveguide layer 1000 having an optical waveguide sub-path is formed. The optical waveguide layer 1000 includes an optical waveguide line formed by a first groove portion, and a beam introduction joint and a beam output joint formed by a second groove and a third groove at both ends of the optical waveguide line.

[0100] In the above manner, several optical waveguide layers may be formed and then stacked.

[0101] Please refer to Fig.12 , a plurality of optical waveguide layers 1000 are stacked and connected so that the optical waveguide sub-paths in each optical waveguide layer 1000 are connected to form an optical waveguide path.

[0102] Specifically, the plurality of optical waveguide layers are bonded and connected by bonding layers 502. After the bonding layers 502 are formed on both sides of the optical waveguide layer, the bonding layers are bonded and fixed to the surface of another optical waveguide layer. The bonding layers will not block the propagation of the light beam. Preferably, silicon dioxide can be used. The carrier 500 plays a fixing and supporting role in the process. After the bonding is completed, it can be removed to continue to stack other optical waveguide layers on the optical waveguide layer 1000.

[0103] The method for forming the above-mentioned optical inertial sensor provided in the embodiment of the present invention can utilize silicon semiconductor micromachining technology to bond multiple layers of silicon wafers (including optical waveguide lines and reflective light beam introduction and export interfaces) to form a coaxial surround optical waveguide line with a length of 5 to 20 kilometers, thereby realizing the physical configuration of a traditional laser optical fiber, that is, a full laser light introducer and a laser signal sensor, that is, the same function of the entire laser fiber inertial navigation can be realized, with the advantages of small size (250mm*320mm area, 1 to 5mm thickness), controllable process, high precision, low power consumption, and controllable overall cost.

[0104] For example, if a SWIR laser light source with a wavelength of 1.3 to 1.6um is selected, the cross section of the light wave can be a silicon layer with a diameter (or lateral length) of 10um. In a volume of 250mm*250mm*1000mm, a light waveguide with a length of about 180m can be constructed. If 80 to 90 layers of silicon layers are bonded, a light waveguide with a length of 15 kilometers can be constructed. The volume of a traditional optical fiber sensor with the same waveguide length will be several times larger.

[0105] The present application also provides an optical inertial sensor formed by the above method.

[0106] Please refer to Fig.12 The optical inertial sensor comprises: a plurality of stacked optical waveguide layers 1000, each optical waveguide layer 1000 comprises a substrate and at least one optical waveguide sub-path arranged in the substrate; the optical waveguide sub-paths in the plurality of stacked optical waveguide layers are interconnected to form an optical waveguide path.

[0107] The optical waveguide sub-path comprises: an optical waveguide line, a light beam introduction joint and a light beam output joint connected at both ends of the optical waveguide line; the light beam introduction joint and the light beam output joint of the optical waveguide layers of adjacent layers are optically aligned and connected.

[0108] Optionally, the optical waveguide sub-channel is filled with a light-guiding medium. Preferably, the light-guiding medium is silicon dioxide.

[0109] Optionally, a light reflecting layer is formed on the inner wall of the optical waveguide sub-channel.

[0110] Optionally, the light reflection layer includes an import reflection plate located on the inner wall of the import joint, and an export reflection plate located on the inner wall of the light beam export joint, and the import reflection plate and the export reflection plate form an angle of 30 to 70 degrees with the substrate plane.

[0111] Optionally, the light reflecting layer includes a metal layer.

[0112] Optionally, the substrate is a semiconductor layer, and the optical waveguide sub-pipelines are all formed by a semiconductor process.

[0113] The specific forming method of the above features is also described in the specific description of the aforementioned embodiments, which will not be repeated here.

[0114] Please refer to Fig.13 The optical inertial sensor further includes: a light sensor 1001 and a light introducer 1002, which are respectively arranged on both sides of the plurality of stacked optical waveguide layers, wherein the light incident end of the light sensor 1001 is opposite to the light outlet of the light beam lead-out connector of the corresponding optical waveguide layer, and the light output end of the light introducer 1002 is opposite to the light incident port of the light beam lead-in connector of the corresponding optical waveguide layer.

[0115] The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structural or equivalent process transformations made using the contents of the specification and drawings of the present application, such as the mutual combination of technical features between the embodiments, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. An optical inertial sensor, characterized in that: include: A plurality of optical waveguide layers are stacked, each optical waveguide layer comprising a substrate and at least one optical waveguide sub-channel arranged in the substrate; The optical waveguide sub-paths in the plurality of stacked optical waveguide layers are interconnected to form an optical waveguide path.

2. The optical inertial sensor according to claim 1, characterized in that: The optical waveguide sub-path comprises: an optical waveguide line, a light beam introduction joint and a light beam output joint connected at both ends of the optical waveguide line; the light beam introduction joint and the light beam output joint of the optical waveguide layers of adjacent layers are optically aligned and connected.

3. The optical inertial sensor according to claim 1, characterized in that: Also includes: The light sensor and the light introducer are respectively arranged on both sides of the plurality of stacked optical waveguide layers, the light incident end of the light sensor is opposite to the light outlet of the light beam lead-out connector of the corresponding optical waveguide layer, and the light output end of the light introducer is opposite to the light incident port of the light beam lead-in connector of the corresponding optical waveguide layer.

4. The optical inertial sensor according to claim 1, characterized in that: The optical waveguide sub-channel is filled with a light guiding medium.

5. The optical inertial sensor according to claim 4, characterized in that: The light guiding medium is silicon dioxide.

6. The optical inertial sensor according to claim 1, characterized in that: A light reflecting layer is formed on the inner wall of the optical waveguide sub-channel.

7. The optical inertial sensor according to claim 1, characterized in that: The light reflection layer includes an import reflection plate located on the inner wall of the import joint and an export reflection plate located on the inner wall of the light beam export joint. The import reflection plate and the export reflection plate form an angle of 30 to 70 degrees with the substrate plane.

8. The optical inertial sensor according to claim 6, characterized in that: The light reflecting layer includes a metal layer.

9. The optical inertial sensor according to claim 1, characterized in that: The substrate is a semiconductor layer, and the optical waveguide sub-pipelines are all formed by semiconductor technology.

10. The optical inertial sensor according to claim 2, characterized in that: The length direction of the optical waveguide sub-pipeline extends in the plane of the substrate, and the openings of the light beam introduction joint and the light beam output joint are respectively located at the opposite first surface and second surface of the substrate.

11. A method for forming an optical inertial sensor, characterized in that: include: forming an optical waveguide layer, the optical waveguide layer comprising: a substrate and at least one optical waveguide sub-path disposed in the substrate; A plurality of optical waveguide layers are stacked and connected so that the optical waveguide sub-paths in each optical waveguide layer are connected to form an optical waveguide path.

12. The forming method according to claim 11, characterized in that: The method for forming the optical waveguide sub-path comprises: forming an optical waveguide line in the substrate, and a light beam introduction joint and a light beam output joint respectively located at two ends of the optical waveguide line; and stacking and connecting a plurality of optical waveguide layers comprises: optically aligning and connecting the light beam introduction joints and light beam output joints of adjacent optical waveguide layers.

13. The forming method according to claim 11, characterized in that: The method for forming the optical waveguide layer comprises: providing a substrate, the substrate comprising a first surface and a second surface opposite to each other; forming a first groove on the first surface of the substrate; A second groove is formed on the first surface of the substrate, the second groove is located at one end of the first groove and connected to the first groove; and the second groove has an inclined side wall on one side, so that the opening size of the second groove is larger than the bottom size; A third groove is formed on the second surface of the substrate, the third groove is located at the other end of the first groove, connected to the first groove, and the third groove has an inclined side wall on one side, so that the opening size of the third groove is larger than the bottom size; The method further includes: filling a light-guiding medium into the first groove, the second groove and the third groove.

14. The forming method according to claim 13, characterized in that: Before forming the second groove, a light-guiding medium is filled in the first groove; before forming the third groove, a light-guiding medium is filled in the second groove.

15. The forming method according to claim 13, characterized in that: The method also includes forming a light reflecting layer on the inner wall surface of each groove.

16. The forming method according to claim 15, characterized in that: The method for forming the light reflecting layer comprises: after forming a first groove, forming a first light reflecting material layer covering the inner wall of the first groove; after forming a second groove, forming a second reflecting material layer on the inner wall surface of the second groove, and one side wall of the second groove exposes the first light reflecting material layer at the end of the first groove; after filling the optical waveguide medium in the second groove, removing the first reflecting material layer and the second reflecting material layer between the second groove and the first groove; forming a third light reflecting material layer covering the surface of the optical waveguide medium in the first groove; after forming a third groove, forming a third reflecting material layer on the inner wall surface of the third groove, and one side wall of the third groove exposes the first light reflecting material layer at the other end of the first groove; after filling the optical waveguide medium in the third groove, removing the first reflecting material layer and the fourth reflecting material layer between the third groove and the first groove.

17. The forming method according to claim 15, characterized in that: Before forming the third groove, the first surface of the substrate is fixed to a carrier surface, and the second surface of the substrate is thinned.

18. The forming method according to claim 11, characterized in that: The plurality of optical waveguide layers are bonded and connected via a bonding layer.

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