Optical chip loop detector and manufacturing method

Abstract

The invention discloses an optical chip loop detector and a manufacturing method, and belongs to the field of optical communication. A core layer of the loop detector is arranged at the joint of the lower cladding and the upper cladding; the radian of the bent waveguide of each waveguide structure of the core layer is pi; the first ends of the two straight waveguides are connected with the two ends of the bent waveguide respectively, and the second ends of the two straight waveguides are connected with the input and output interfaces respectively; the at least two U-shaped optical waveguide assemblies are similar in shape and are arranged in an array from small to large and from inside to outside, and the distance between every two adjacent straight waveguides in the straight waveguides located on the same side is equal. The lower cladding, the upper cladding and the U-shaped optical waveguide assembly are all made of polymer materials, the difference between the material refractive index of the U-shaped optical waveguide assembly and the material refractive index of the lower cladding and the material refractive index of the upper cladding ranges from 7% to 17.5%, and the absorption loss of the U-shaped optical waveguide assembly ranges from 0.005 dB / mm to 0.2 dB / mm. According to the invention, low-insertion-loss and low-crosstalk self-loop detection and multichannel insertion loss equalization of the multi-channel light receiving and emitting chip can be realized.

Description

Technical Field

[0001] The present application relates to the field of optical communication technology, and in particular to an optical chip loop detector and a manufacturing method thereof. Background Art

[0002] Optical chips are essential components for photoelectric signal conversion and play a core role in cutting-edge fields such as optical communications and photonic computing. Accurate evaluation of optical chip performance is crucial to promoting the continuous advancement of optical integration technology. Especially in the manufacturing and testing process of multi-channel transmitting and receiving optical chips, the accuracy of performance evaluation directly affects the final quality and reliability of the product.

[0003] Traditional testing methods often require external cumbersome fiber optic connections and precision instruments, which not only greatly increases the complexity and time cost of the testing process, but may also introduce additional coupling losses due to fiber coupling and other links, which in turn has an adverse effect on the accuracy of the test results. In contrast, the existing loop detector has become an ideal solution for multi-channel transceiver optical chip testing with its high efficiency, compactness and low cost. It cleverly uses the precisely designed optical circuit to realize the direct interconnection test between the transmitter and the receiver. It realizes the self-consistent test of the transmitter and the receiver by building a complete optical circuit inside the optical chip, which greatly simplifies the test process and significantly improves production efficiency. Specifically, the loop detector can automatically complete the complete optoelectronic signal conversion and detection process from transmission to reception on the chip, without the need for additional fiber optic connections and test equipment, thereby effectively avoiding errors and losses introduced by external equipment. This testing method not only improves the accuracy and stability of the test, but also greatly reduces the test cost and improves the overall production efficiency.

[0004] However, as optical chips develop towards multi-channel, high-speed and miniaturization, existing loop detectors face many challenges. In multi-channel testing, the crosstalk between channels of existing loop detectors will reduce the test accuracy. At the same time, the insertion loss of the on-chip loop structure will directly affect the reliability of loop detection. In addition, the multi-channel insertion loss of the loop detector is uneven. Summary of the invention

[0005] The embodiments of the present application provide an optical chip loop detector and a manufacturing method, which can solve the problem that crosstalk between channels of the existing loop detector will reduce the test accuracy. At the same time, the insertion loss of the on-chip loop structure will directly affect the reliability of the loop detection. In addition, the loop detector has the problem of uneven insertion loss of multiple channels.

[0006] In order to achieve the above object, the technical solution of the embodiment of the present invention is:

[0007] In a first aspect, an embodiment of the present invention provides an optical chip loop detector, including a substrate, a lower cladding layer, a core layer, and an upper cladding layer;

[0008] The substrate, the lower cladding layer and the upper cladding layer are overlapped from bottom to top;

[0009] The core layer is arranged at the junction of the lower cladding layer and the upper cladding layer;

[0010] The core layer includes at least two waveguide structures;

[0011] Each of the waveguide structures comprises a U-shaped optical waveguide component, an input interface and an output interface;

[0012] The U-shaped optical waveguide assembly includes two straight waveguides and one curved waveguide;

[0013] The curvature of the curved waveguide is π;

[0014] The two straight waveguides are arranged in parallel, the first ends on the same side are respectively connected to the two ends of the curved waveguide, and the second ends on the same side are respectively connected to the input interface and the output interface;

[0015] At least two of the U-shaped optical waveguide components are similar in shape and are arranged in an array from small to large and from inside to outside, and the distance between two adjacent straight waveguides on the same side is equal;

[0016] The lower cladding, the upper cladding and the U-shaped optical waveguide component are all made of polymer materials, and the difference between the material refractive index of the U-shaped optical waveguide component and the material refractive index of the lower cladding is 7% to 17.5%, the difference between the material refractive index of the U-shaped optical waveguide component and the material refractive index of the upper cladding is 7% to 17.5%, and the absorption loss of the U-shaped optical waveguide component is 0.005dB / mm to 0.2dB / mm.

[0017] In combination with the first aspect, in a possible implementation, the U-shaped optical waveguide component is made of an organic-inorganic hybrid resin polymer material;

[0018] And / or, the lower cladding layer is made of fluorinated acrylate resin polymer material;

[0019] And / or, the upper cladding layer is made of fluorinated acrylate resin polymer material.

[0020] In combination with the first aspect, in a possible implementation manner, a cross-section of the U-shaped optical waveguide component in a direction perpendicular to its length extension is a rectangle.

[0021] In combination with the first aspect, in a possible implementation manner, the length of the rectangle is 2 μm to 10 μm, and the width is 2 μm to 10 μm.

[0022] In combination with the first aspect, in a possible implementation manner, a length calculation formula of the straight waveguide is:

[0023]

[0024] Wherein, l is the length of the straight waveguide, L is the single-channel insertion loss of the U-shaped optical waveguide component, b is the bending loss of the U-shaped optical waveguide component, a is the transmission loss of the U-shaped optical waveguide component, π is pi, and R is the bending radius of the curved waveguide.

[0025] In a second aspect, an embodiment of the present invention provides a method for manufacturing an optical chip loop detector, which is used to prepare the optical chip loop detector described above, comprising:

[0026] Spin coating and UV curing the lower cladding photoresist on the substrate to obtain the lower cladding;

[0027] Spin-coating a U-shaped optical waveguide component photoresist on the lower cladding layer, and then performing mask photolithography to obtain a U-shaped optical waveguide component, wherein the U-shaped optical waveguide component includes two straight waveguides and one curved waveguide; the curvature of the curved waveguide is π; the two straight waveguides are arranged in parallel, the first ends on the same side are respectively connected to the two ends of the curved waveguide, and the second ends on the same side are respectively connected to the input interface and the output interface; the U-shaped optical waveguide component, the input interface and the output interface constitute a waveguide structure; at least two of the waveguide structures are similar in shape, arranged in an array from small to large and from inside to outside, and the distance between two adjacent straight waveguides on the same side is equal;

[0028] The upper cladding layer photoresist is spin-coated on the core layer and UV-cured to obtain the upper cladding layer, which is then thermally cured so that the substrate, the lower cladding layer and the upper cladding layer are overlapped from bottom to top; the core layer is arranged at the junction of the lower cladding layer and the upper cladding layer; wherein the lower cladding layer, the upper cladding layer and the U-shaped optical waveguide component are all made of polymer materials, and the difference between the material refractive index of the U-shaped optical waveguide component and the material refractive index of the lower cladding layer is 7% to 17.5%, the difference between the material refractive index of the U-shaped optical waveguide component and the material refractive index of the upper cladding layer is 7% to 17.5%, and the absorption loss of the U-shaped optical waveguide component is 0.005dB / mm to 0.2dB / mm.

[0029] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0030] In the optical chip loop detector provided by the embodiment of the present invention, at least two U-shaped optical waveguide components are similar in shape, arranged in an array from small to large and from inside to outside, and the distance d between two adjacent straight waveguides in the straight waveguide on the same side is equal, that is, at least two waveguide structures are non-overlapping and equidistant, so as not to bring additional interference between channels, and realize low crosstalk between waveguide structures. In addition, the U-shaped optical waveguide components with different sizes can realize multi-channel insertion loss balance. The lower cladding, the upper cladding and the U-shaped optical waveguide component are all made of polymer materials, and the difference between the material refractive index of the U-shaped optical waveguide component and the material refractive index of the lower cladding is 7% to 17.5%, the difference between the material refractive index of the U-shaped optical waveguide component and the material refractive index of the upper cladding is 7% to 17.5%, and the absorption loss of the U-shaped optical waveguide component is 0.005dB / mm to 0.2dB / mm, so as to meet the total reflection condition of the optical signal under the extremely small bending radius of the curved waveguide, and realize the low insertion loss transmission of the U-shaped optical waveguide component. From the above, it can be seen that the optical chip loop detector provided in the embodiment of the present application can realize low insertion loss and low crosstalk self-loop detection of multi-channel transmitting and receiving optical chips, and multi-channel insertion loss balance, thereby improving test accuracy and detection reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0032] Figure 1 A three-dimensional diagram of an optical chip loop detector provided in an embodiment of the present application;

[0033] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0034] Figure 3 A front view of an optical chip loop detector provided in an embodiment of the present application;

[0035] Figure 4 This is a diagram showing the simulation calculation results of the bending loss of the optical chip loop detector provided in the specific embodiment of the present application when the operating wavelength is 1310nm.

[0036] Icon: 1-lower cladding; 2-core layer; 21-waveguide structure; 211-U-type optical waveguide component; 211a-straight waveguide; 211b-bent waveguide; 3-upper cladding. DETAILED DESCRIPTION

[0037] 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 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.

[0038] In the description of the embodiments of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limitations on the present invention. The terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. In addition, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to the specific circumstances.

[0039] Please refer to Figure 1 and Figure 3 As shown, an embodiment of the present invention provides an optical chip loop detector, including a substrate, a lower cladding layer 1, a core layer 2 and an upper cladding layer 3.

[0040] The substrate, the lower cladding layer 1 and the upper cladding layer 3 are overlapped from bottom to top. In the actual manufacturing process, the lower cladding layer 1 is overlapped on the upper surface of the substrate. The upper cladding layer 3 is overlapped on the upper surface of the lower cladding layer 1.

[0041] The core layer 2 is arranged at the junction of the lower cladding layer 1 and the upper cladding layer 3 , so that the lower cladding layer 1 and the upper cladding layer 3 can protect the core layer 2 .

[0042] The core layer 2 includes at least two waveguide structures 21. For example, the core layer 2 includes two, three, four, five, six, etc. waveguide structures 21, preferably two to twelve waveguide structures 21 with balanced insertion loss, such as Figure 1 and Figure 2 The schematic diagram shows that the core layer 2 includes four waveguide structures 21 .

[0043] Each waveguide structure 21 includes a U-shaped optical waveguide component 211 , an input interface and an output interface.

[0044] The U-shaped optical waveguide assembly 211 includes two straight waveguides 211a and one curved waveguide 211b. The arc of the curved waveguide 211b is π, that is, 180°.

[0045] Two straight waveguides 211a are arranged in parallel, and the first ends on the same side are respectively connected to the two ends of the curved waveguide 211b (since the curvature of the curved waveguide 211b is π, the two straight waveguides 211a are parallel, and the first ends on the same side are respectively perpendicular to the end faces of the two ends connected to the curved waveguide 211b, the connection point has good continuity, and the insertion loss is minimized. If the curvature of the curved waveguide 211b is less than π, it is ensured that one straight waveguide 211a is perpendicular to the end face of one end of the curved waveguide 211b, and at the same time, it is ensured that the other straight waveguide 211a is perpendicular to the end face of the other end of the curved waveguide 211b, then the two straight waveguides 211a are perpendicular to each other. 11a cannot be guaranteed to be parallel, or one end face of a straight waveguide 211a is guaranteed to be perpendicular to one end face of a curved waveguide 211b, and if two straight waveguides 211a are guaranteed to be parallel, then the other end face of another straight waveguide 211a and the curved waveguide 211b cannot be guaranteed to be perpendicular, the connection point continuity is poor, and the insertion loss is large), the second end on the same side is respectively connected to the input interface and the output interface, the input interface and the output interface are respectively connected to the optical chip transceiver module, and then the optical signal is transmitted from the input interface to the U-shaped optical waveguide component 211 and then transmitted from the output interface, so as to realize the loop detection of multi-channel transceiver optical chips. When the core layer 2 includes four waveguide structures 21, the loop detection of four-channel transceiver chips can be realized.

[0046] like Figure 1 and Figure 3 As shown, at least two U-shaped optical waveguide components 211 are similar in shape and are arranged in an array from small to large and from inside to outside (i.e., the length of the inner straight waveguide 211a is less than or equal to the length of the outer straight waveguide 211a, and the length of the inner curved waveguide 211b is less than or equal to the length of the outer curved waveguide 211b), and the distance d between two adjacent straight waveguides 211a on the same side is equal, and the distance d is 250 μm for example. That is, at least two waveguide structures 21 are non-overlapping and equidistant, so as not to cause additional interference between channels.

[0047] The lower cladding 1, the upper cladding 3 and the U-shaped optical waveguide component 211 are all made of polymer materials, and the difference between the material refractive index of the U-shaped optical waveguide component 211 and the material refractive index of the lower cladding 1 is 7% to 17.5%, and the difference between the material refractive index of the U-shaped optical waveguide component 211 and the material refractive index of the upper cladding 3 is 7% to 17.5% (generally, the material refractive index range of the U-shaped optical waveguide component 211 is 1.5 to 1.7, the material refractive index range of the upper cladding 3 is 1.4 to 1.5, and the material refractive index range of the lower cladding 1 is 1.4 to 1.5). The absorption loss of the U-shaped optical waveguide component 211 is 0.005 dB / mm to 0.2 dB / mm, thereby satisfying the total reflection condition of the optical signal under the extremely small bending radius of the bending waveguide 211b, and realizing low insertion loss transmission of the U-shaped optical waveguide component 211 (insertion loss <9 dB). In practical applications, suitable polymer materials can be selected according to specific needs, thereby improving the flexibility of the optical chip loop detector design.

[0048] The optical chip loop detector provided by the embodiment of the present invention has at least two U-shaped optical waveguide components 211 with similar shapes, which are arranged in an array from small to large and from inside to outside, and the distance d between two adjacent straight waveguides 211a located on the same side is equal, that is, at least two waveguide structures 21 have no overlap and are equidistant, so as not to cause additional interference between channels, thereby achieving low crosstalk between the waveguide structures 21. In addition, arranging U-shaped optical waveguide components 211 of inconsistent sizes can achieve multi-channel insertion loss balance. The lower cladding 1, the upper cladding 3 and the U-shaped optical waveguide component 211 are all made of polymer materials, and the difference between the material refractive index of the U-shaped optical waveguide component 211 and the material refractive index of the lower cladding 1 is 7% to 17.5%, the difference between the material refractive index of the U-shaped optical waveguide component 211 and the material refractive index of the upper cladding 3 is 7% to 17.5%, and the absorption loss of the U-shaped optical waveguide component 211 is 0.005dB / mm to 0.2dB / mm, thereby satisfying the total reflection condition of the optical signal under the extremely small bending radius of the curved waveguide 211b, and realizing the low insertion loss transmission of the U-shaped optical waveguide component 211. It can be seen from the above that the optical chip loop detector provided in the embodiment of the present application can realize the self-loop detection of multi-channel receiving and transmitting optical chips with low insertion loss and low crosstalk, and the multi-channel insertion loss balance, thereby improving the test accuracy and detection reliability.

[0049] Optionally, the U-shaped optical waveguide component 211 is made of organic-inorganic hybrid resin polymer material. Organic-inorganic hybrid resin polymer material has the advantages of excellent heat resistance, good chemical corrosion resistance, good mechanical properties, good aging resistance, good air permeability and waterproofness.

[0050] And / or, the lower cladding 1 is made of fluorinated acrylate resin polymer material. And / or, the upper cladding 3 is made of fluorinated acrylate resin polymer material. Fluorinated acrylate resin polymer has the advantages of low surface energy and low friction, good weather resistance, good chemical stability, high transparency, low refractive index, etc. The upper cladding 3 and the lower cladding 1 can be made of the same material or different materials, which can be determined according to actual needs.

[0051] The U-shaped optical waveguide component 211 is made of an organic-inorganic hybrid resin polymer material, the lower cladding 1 is made of a fluorinated acrylate resin polymer material, and the upper cladding 3 is made of a fluorinated acrylate resin polymer material. A polymer optical waveguide with a high refractive index contrast can be further prepared, and the waveguide has an extremely small bending radius at the bending part, which can realize a compact optical circuit with low insertion loss, thereby meeting the functional requirements of the optical chip loop detector.

[0052] The optical chip loop detector provided in the embodiment of the present application has a spacing of 250 μm between the input interface and the output interface, a distance of 250 μm between two adjacent straight waveguides 211a on the same side, and a bending radius of the corresponding curved waveguide 211b of 125 μm.

[0053] Furthermore, if Figure 2 As shown, the cross section of the U-shaped optical waveguide component 211 in the direction perpendicular to the length extension is rectangular, so that it is convenient to manufacture using existing processes. Of course, the cross section of the U-shaped optical waveguide component 211 in the direction perpendicular to the length extension can also be circular or semicircular.

[0054] Optionally, the length of the rectangle is 2μm to 10μm (can be 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, etc. typical but non-limiting length), and the width is 2μm to 10μm (can be 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, etc. typical but non-limiting width). For example, the optical chip loop detector of the embodiment of the present application has a length of 4μm and a width of 4μm.

[0055] Furthermore, the length calculation formula of the straight waveguide 211a is:

[0056]

[0057] Wherein, l is the length of the straight waveguide 211a, L is the single-channel insertion loss of the U-shaped optical waveguide component 211, b is the bending loss of the U-shaped optical waveguide component 211, a is the transmission loss of the U-shaped optical waveguide component 211, π is pi, and R is the bending radius of the curved waveguide 211b.

[0058] In practice, the length calculation formula of the straight waveguide 211a is derived from the insertion loss calculation formula L = a(πR+2l)+b, which ensures that the insertion losses of multiple U-shaped optical waveguide components 211 are consistent: (a1(πR1+2l1)+b1=a2(πR2+2l2)+b2=…=a n (πR n +2l n )+b n =L), that is, insertion loss balance, the length of each straight waveguide 211a is calculated, so that the optical chip loop detector provided in the embodiment of the present application can ensure multi-channel insertion loss balance by setting straight waveguides 211a and curved waveguides 211b of different lengths.

[0059] For example, Figure 1 and Figure 3 In the example of 8 cores and 4 channels provided, the bending radius R1 of the innermost curved waveguide 211b is 125μm, and the bending loss b1 is 1.01dB; the bending radius R2 of the second innermost curved waveguide 211b is 375μm, and the bending loss b2 is 0.63dB; the bending radius R3 of the second outermost curved waveguide 211b is 625μm, and the bending loss b3 is 0.24dB; the bending radius R4 of the outermost curved waveguide 211b is 875μm, and the bending loss b4 is 0.013dB. The length of the straight waveguide 211al1 is 1mm, the length l2 of the straight waveguide 211a is 2.3mm, the length l3 of the straight waveguide 211a is 3.5mm, and the length l4 of the straight waveguide 211a is 4.1mm. The transmission loss a is 0.12dB / mm. The single-channel insertion loss L is 1.3dB.

[0060] Among them, a and b are calculated by software simulation based on the absorption loss of the material, waveguide cross-sectional dimensions, refractive index, wavelength and other parameters. With the simulated a and b, the specific value of l can be calculated based on the insertion loss L (usually 0.5dB to 9dB, preferably less than 3dB) as required.

[0061] A specific embodiment of the present invention is provided herein.

[0062] An optical chip loop detector comprises a substrate, a lower cladding layer 1, a core layer 2 and an upper cladding layer 3. The substrate, the lower cladding layer 1 and the upper cladding layer 3 are overlapped from bottom to top. The core layer 2 is arranged at the junction of the lower cladding layer 1 and the upper cladding layer 3. The core layer 2 comprises at least two waveguide structures 21.

[0063] Each waveguide structure 21 includes a U-shaped optical waveguide component 211, an input interface and an output interface. The U-shaped optical waveguide component 211 includes two straight waveguides 211a and one curved waveguide 211b. The radian of the curved waveguide 211b is π. The two straight waveguides 211a are arranged in parallel, and the first ends on the same side are respectively connected to the two ends of the curved waveguide 211b, and the second ends on the same side are respectively connected to the input interface and the output interface. At least two U-shaped optical waveguide components 211 are similar in shape, arranged in an array from small to large and from inside to outside, and the distance d between two adjacent straight waveguides 211a on the same side is equal.

[0064] The lower cladding 1, the upper cladding 3 and the U-shaped optical waveguide component 211 are all made of polymer materials, and the difference between the refractive index of the material of the U-shaped optical waveguide component 211 and the lower cladding 1 is 9%, the difference between the refractive index of the material of the U-shaped optical waveguide component 211 and the upper cladding 3 is 9%, and the absorption loss of the U-shaped optical waveguide component 211 is 0.005dB / mm to 0.2dB / mm. The U-shaped optical waveguide component 211 is made of organic-inorganic hybrid resin polymer material. The lower cladding 1 is made of fluorinated acrylate resin polymer material. The upper cladding 3 is made of fluorinated acrylate resin polymer material. The curvature of the curved waveguide 211b is π. The cross section of the U-shaped optical waveguide component 211 in the vertical length extension direction is a rectangle. The length of the rectangle is 4μm and the width is 4μm.

[0065] Figure 4 This is a simulation calculation result diagram of the bending loss of the optical chip loop detector provided by the specific embodiment of the present invention when the working wavelength is 1310nm. Figure 4 When the difference between the refractive index of the U-shaped optical waveguide component 211 and the refractive index of the lower cladding 1 is 9% and the difference between the refractive index of the U-shaped optical waveguide component 211 and the refractive index of the upper cladding 3 is 9%, the bending loss of the curved waveguide 211b with a bending radius of 125 μm can still be maintained within 1.1 dB, which can meet the low insertion loss requirements of the optical chip loop detector.

[0066] Another embodiment of the present invention provides a method for manufacturing an optical chip loop detector, which is used to prepare the above-mentioned optical chip loop detector, comprising:

[0067] Step 1: Spin coating and UV curing the lower cladding layer 1 photoresist on the substrate to obtain the lower cladding layer 1. The structure of the lower cladding layer 1 is uniform. For some polymer materials used to make the lower cladding layer 1, oxygen inhibition may occur during the UV exposure process. In order to reduce the influence of oxygen on the polymer material, nitrogen protection measures can be used.

[0068] Step 2: Spin-coat the U-shaped optical waveguide component 211 photoresist on the lower cladding 1, and then perform mask photolithography to obtain the U-shaped optical waveguide component 211, wherein the U-shaped optical waveguide component 211 includes two straight waveguides 211a and one curved waveguide 211b, and the curvature of the curved waveguide 211b is π. The two straight waveguides 211a are arranged in parallel, and the first ends on the same side are respectively connected to the two ends of the curved waveguide 211b, and the second ends on the same side are respectively connected to the input interface and the output interface. The U-shaped optical waveguide component 211, the input interface and the output interface constitute a waveguide structure 21. At least two waveguide structures 21 are similar in shape, arranged in an array from small to large and from inside to outside, and the distance d between two adjacent straight waveguides 211a on the same side is equal.

[0069] Step 3: Spin coating and UV curing the photoresist of the upper cladding layer 3 on the core layer 2 to obtain the upper cladding layer 3, and then heat curing to make the substrate, the lower cladding layer 1 and the upper cladding layer 3 overlap from bottom to top. The core layer 2 is arranged at the junction of the lower cladding layer 1 and the upper cladding layer 3. Among them, the lower cladding layer 1, the upper cladding layer 3 and the U-shaped optical waveguide component 211 are all made of polymer materials, and the difference between the material refractive index of the U-shaped optical waveguide component 211 and the material refractive index of the lower cladding layer 1 is 7% to 17.5%, the difference between the material refractive index of the U-shaped optical waveguide component 211 and the material refractive index of the upper cladding layer 3 is 7% to 17.5%, and the absorption loss of the U-shaped optical waveguide component 211 is 0.005dB / mm to 0.2dB / mm.

[0070] The manufacturing method of the optical chip loop detector provided in the embodiment of the present invention is simple and easy to implement. The prepared optical chip loop detector can realize self-loop detection of multi-channel transmitting and receiving optical chips with low insertion loss and low crosstalk, and multi-channel insertion loss balance, thereby improving test accuracy and detection reliability.

[0071] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments.

[0072] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. An optical chip loop detector, characterized in that: It includes a substrate, a lower cladding layer, a core layer and an upper cladding layer; The substrate, the lower cladding layer and the upper cladding layer are overlapped from bottom to top; The core layer is arranged at the junction of the lower cladding layer and the upper cladding layer; The core layer includes at least two waveguide structures; Each of the waveguide structures comprises a U-shaped optical waveguide component, an input interface and an output interface; The U-shaped optical waveguide assembly includes two straight waveguides and one curved waveguide; The curvature of the curved waveguide is π; The two straight waveguides are arranged in parallel, the first ends on the same side are respectively connected to the two ends of the curved waveguide, and the second ends on the same side are respectively connected to the input interface and the output interface; At least two of the U-shaped optical waveguide components are similar in shape and are arranged in an array from small to large and from inside to outside, and the distance between two adjacent straight waveguides on the same side is equal; The lower cladding, the upper cladding and the U-shaped optical waveguide component are all made of polymer materials, and the difference between the material refractive index of the U-shaped optical waveguide component and the material refractive index of the lower cladding is 7% to 17.5%, the difference between the material refractive index of the U-shaped optical waveguide component and the material refractive index of the upper cladding is 7% to 17.5%, and the absorption loss of the U-shaped optical waveguide component is 0.005dB / mm to 0.2dB / mm.

2. The optical chip loop detector according to claim 1, characterized in that: The U-shaped optical waveguide component is made of organic-inorganic hybrid resin polymer material; And / or, the lower cladding layer is made of fluorinated acrylate resin polymer material; And / or, the upper cladding layer is made of fluorinated acrylate resin polymer material.

3. The optical chip loop detector according to claim 1, characterized in that: The cross section of the U-shaped optical waveguide component in the vertical length extension direction is rectangular.

4. The optical chip loop detector according to claim 3, characterized in that: The rectangle has a length of 2 μm to 10 μm and a width of 2 μm to 10 μm.

5. The optical chip loop detector according to claim 1, characterized in that: The length calculation formula of the straight waveguide is: Wherein, l is the length of the straight waveguide, L is the single-channel insertion loss of the U-shaped optical waveguide component, b is the bending loss of the U-shaped optical waveguide component, a is the transmission loss of the U-shaped optical waveguide component, π is pi, and R is the bending radius of the curved waveguide.

6. A method for manufacturing an optical chip loop detector, characterized in that: Used to prepare the optical chip loop detector according to any one of claims 1 to 5, comprising: Spin coating and UV curing the lower cladding photoresist on the substrate to obtain the lower cladding; Spin-coating a U-shaped optical waveguide component photoresist on the lower cladding layer, and then performing mask photolithography to obtain a U-shaped optical waveguide component, wherein the U-shaped optical waveguide component includes two straight waveguides and one curved waveguide; the curvature of the curved waveguide is π; the two straight waveguides are arranged in parallel, the first ends on the same side are respectively connected to the two ends of the curved waveguide, and the second ends on the same side are respectively connected to the input interface and the output interface; the U-shaped optical waveguide component, the input interface and the output interface constitute a waveguide structure; at least two of the waveguide structures are similar in shape, arranged in an array from small to large and from inside to outside, and the distance between two adjacent straight waveguides on the same side is equal; The upper cladding layer photoresist is spin-coated on the core layer and UV-cured to obtain the upper cladding layer, which is then thermally cured so that the substrate, the lower cladding layer and the upper cladding layer are overlapped from bottom to top; the core layer is arranged at the junction of the lower cladding layer and the upper cladding layer; wherein the lower cladding layer, the upper cladding layer and the U-shaped optical waveguide component are all made of polymer materials, and the difference between the material refractive index of the U-shaped optical waveguide component and the material refractive index of the lower cladding layer is 7% to 17.5%, the difference between the material refractive index of the U-shaped optical waveguide component and the material refractive index of the upper cladding layer is 7% to 17.5%, and the absorption loss of the U-shaped optical waveguide component is 0.005dB / mm to 0.2dB / mm.

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