Molecular fluorescence detection chip and optical packaging structure thereof

Abstract

The invention provides a molecular fluorescence detection chip and an optical packaging structure thereof, a fluorescence excitation layer of the chip comprises an input optical coupling module, an optical beam splitter tree structure, a fluorescence excitation structure array, an optical coupling structure array and an optical feedback structure, and the input end of the optical feedback structure is connected with one output end of the optical beam splitter tree structure. The optical packaging structure comprises an optical fiber module and the molecular fluorescence detection chip, the optical fiber module is fixed at a preset position of the chip and comprises one or more optical input channels, and the optical input channels are aligned with the input optical coupling unit of the input optical coupling module. According to the passive optical coupling scheme, the optical coupling efficiency does not change along with mechanical vibration of the environment, so that the stability of exciting light in the chip is improved, the stability of a fluorescence signal is further facilitated, meanwhile, the complexity of an optical path of external equipment is also reduced, and the equipment cost is saved. In addition, the number of lasers can be increased in a multi-channel coupling-in mode, so that the in-chip excitation light power is improved, and the signal-to-noise ratio is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of biochips and relates to a molecular fluorescence detection chip and an optical packaging structure thereof. Background Art

[0002] Biochip technology is a comprehensive high-tech technology that involves biology, chemistry, medicine, precision machining, optics, microelectronics, informatics and other fields. It is a hot topic with strong interdisciplinary nature. In recent years, the excitation and collection of biological fluorescence signals through optical integrated chips have gradually shown important value and potential in the field of fluorescent molecule detection, especially in the field of single-molecule fluorescence detection.

[0003] This technology uses semiconductor manufacturing processes to achieve a monolithic integrated solution from fluorescence signal excitation, fluorescence signal collection, to fluorescence signal detection. By generating nanoscale sample restriction sites on a large scale on the chip surface and combining biochemical modification methods, spatial restriction at the single-molecule scale is achieved. In addition, compared to the traditional optical system method of exciting and collecting fluorescence signals, this technology uses an evanescent field to excite fluorescence through an optical waveguide, achieving simultaneous excitation of large-flux sites, and using the on-chip collection structure to make the sample restriction sites correspond to the detection pixels, achieving simultaneous collection of fluorescence signals at large-flux sites, and ultimately achieving fluorescence detection at large-flux sites.

[0004] However, the effect of this technology is highly dependent on the performance of specific fluorescent signal detection, and requires the on-chip excitation light power to maintain a certain degree of stability, which largely depends on the connection stability and vibration resistance of the optical system. The current solution of using an optical feedback system to monitor and adjust the coupling between the off-chip light source and the chip in real time can achieve the effect of stabilizing the on-chip optical power, but it requires a complex, high-precision, high-frequency response optomechanical system, which greatly increases the cost of sequencing instruments.

[0005] Therefore, how to provide a molecular fluorescence detection chip and its optical packaging structure so as to achieve the stability of the on-chip optical power and reduce the cost of the sequencer has become an important technical problem that needs to be solved urgently by those skilled in the art.

[0006] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of the present application and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because they are described in the background technology section of the present application. Summary of the invention

[0007] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a molecular fluorescence detection chip and an optical packaging structure thereof, so as to solve the problem in the prior art that it is difficult to achieve stable on-chip optical power at a relatively low cost.

[0008] To achieve the above-mentioned purpose and other related purposes, the present invention provides a molecular fluorescence detection chip, comprising a fluorescence detection layer, a fluorescence collection layer and a fluorescence excitation layer arranged in sequence from bottom to top, wherein the fluorescence excitation layer comprises:

[0009] An input light coupling module, wherein the input light coupling module comprises one or more input light coupling units;

[0010] An optical beam splitter tree structure, wherein the input end of the optical beam splitter tree structure is connected to the output end of the input optical coupling module, and the optical beam splitter tree structure comprises a first output end and multiple second output ends;

[0011] A fluorescence excitation structure array, wherein an input end of the fluorescence excitation structure array is connected to a second output end of the optical beam splitter tree structure;

[0012] An optical coupling-out structure array, wherein an input end of the optical coupling-out structure array is connected to an output end of the fluorescence excitation structure array;

[0013] An optical feedback structure, wherein an input end of the optical feedback structure is connected to a first output end of the optical beam splitter tree structure.

[0014] Optionally, the input light coupling module includes a plurality of the input light coupling units, and the fluorescence excitation layer further includes an optical power balancing module, and the optical power balancing module is connected between the input light coupling module and the optical beam splitter tree structure.

[0015] Optionally, the optical power balancing module includes an N×N optical beam combining structure, wherein N is consistent with the number of the input optical coupling units, and the N×N optical beam combining structure includes a 2×2 optical coupler, or includes a plurality of cascaded 2×2 optical couplers, and the 2×2 optical coupler adopts a directional coupler or a multimode interference coupler.

[0016] Optionally, the optical feedback structure includes a 1×2 optical beam splitter, a first feedback optical coupling unit and a second feedback optical coupling unit, the input optical coupling module is located between the first feedback optical coupling unit and the second feedback optical coupling unit, the first feedback optical coupling unit, the input optical coupling unit and the second feedback optical coupling unit are arranged in a straight line at equal intervals perpendicular to the light propagation direction, the input end of the 1×2 optical beam splitter is connected to the first output end of the optical beam splitter tree structure, the input end of the first feedback optical coupling unit is connected to the first output end of the 1×2 optical beam splitter, and the input end of the second feedback optical coupling unit is connected to the second output end of the 1×2 optical beam splitter; the output end of the first feedback optical coupling unit, the input end of the input optical coupling unit and the output end of the second feedback optical coupling unit are all used to connect to an optical fiber module, the optical fiber module includes a first optical feedback channel, an optical input channel and a second optical feedback channel arranged side by side, the output end of the first feedback optical coupling unit is connected to the first optical feedback channel, the input end of the input optical coupling unit is connected to the optical input channel, and the output end of the second feedback optical coupling unit is connected to the second optical feedback channel.

[0017] Optionally, an emission angle range of the first feedback light coupling unit and the second feedback light coupling unit is 8 to 10 degrees, and a near-field light spot diameter range is 3 to 5 microns.

[0018] Optionally, the optical feedback structure comprises a feedback optical coupling unit, the input end of the feedback optical coupling unit is connected to the first output end of the optical beam splitter tree structure, and the output end of the feedback optical coupling unit is used to connect to an off-chip optical system.

[0019] Optionally, the output angle range of the feedback light coupling unit is 30 to 60 degrees, the near-field light spot diameter range is 30 to 60 microns, and the output light spot is collected by the off-chip optical system in free space.

[0020] Optionally, the optical feedback structure includes a first 1×2 optical beam splitter, a second 1×2 optical beam splitter, a first feedback optical coupling unit, a second feedback optical coupling unit and a third feedback optical coupler, the input optical coupling module is located between the first feedback optical coupling unit and the second feedback optical coupling unit, the first feedback optical coupling unit, the input optical coupling unit and the second feedback optical coupling unit are arranged in a straight line at equal intervals perpendicular to the light propagation direction, the input end of the first 1×2 optical beam splitter is connected to the first output end of the optical beam splitter tree structure, the input end of the second 1×2 optical beam splitter is connected to the first output end of the first 1×2 optical beam splitter, the input end of the first feedback optical coupling unit is connected to the first output end of the second 1×2 optical beam splitter, and the The input end of the second feedback optical coupling unit is connected to the second output end of the second 1×2 optical beam splitter, and the input end of the third feedback optical coupling unit is connected to the second output end of the first 1×2 optical beam splitter; the output end of the first feedback optical coupling unit, the input end of the input optical coupling unit and the output end of the second feedback optical coupling unit are all used to connect to an optical fiber module, and the optical fiber module includes a first optical feedback channel, an optical input channel and a second optical feedback channel arranged side by side, the output end of the first feedback optical coupling unit is connected to the first optical feedback channel, the input end of the input optical coupling unit is connected to the optical input channel, and the output end of the second feedback optical coupling unit is connected to the second optical feedback channel; the output end of the third feedback optical coupling unit is used to connect to an off-chip optical system.

[0021] Optionally, the emission angle range of the first feedback light coupling unit and the second feedback light coupling unit is 8 to 10 degrees, and the near-field spot diameter range is 3 to 5 microns; the emission angle range of the third feedback light coupling unit is 30 to 60 degrees, and the near-field spot diameter range is 30 to 60 microns, and the emission spot is collected by the off-chip optical system in free space.

[0022] Optionally, the optical beam splitter tree structure includes one or more optical beam splitter units, and the optical beam splitter unit includes one or more of a Y-branch structure, a 2×2 directional coupler, a 1×2 multimode interference coupler, a 2×2 multimode interference coupler, a 1×3 multimode interference coupler and a 1×5 multimode interference coupler.

[0023] Optionally, the fluorescence excitation structure array includes a cladding and one or more waveguide structures coated in the cladding, and the surface of the cladding above the waveguide structure is provided with sample wells arranged at a certain period along the waveguide propagation direction, and the sample wells are used to load molecular substances that can excite fluorescence, and the distance between the bottom surface of the sample well and the top surface of the waveguide structure is less than the evanescent wave penetration distance of the waveguide structure.

[0024] Optionally, the waveguide structure adopts a straight waveguide, and the sample well is located directly above the straight waveguide; or the waveguide structure includes a straight waveguide and a plurality of grating structures located on one side of the straight waveguide and connected to the straight waveguide, and the sample well is located directly above the grating structure; or the waveguide structure includes a straight waveguide and a V-shaped metal grating structure located on the straight waveguide, and the sample well is located directly above the V-shaped metal grating structure.

[0025] Optionally, the light out-coupling structure array includes a plurality of light out-coupling units, and the light out-coupling units adopt grating couplers.

[0026] Optionally, the fluorescence collection layer includes a fluorescence filter layer, an aperture layer and a microlens array layer.

[0027] Optionally, the fluorescence detection layer includes one or more of a CCD chip, a CMOS image sensor chip, a PD array, a SPAD array, a PMT array and a SiPM array.

[0028] The present invention also provides an optical packaging structure, comprising an optical fiber module and a molecular fluorescence detection chip as described above, wherein the optical fiber module is fixed at a preset position of the molecular fluorescence detection chip, and the optical fiber module comprises one or more optical input channels, and the optical input channels are aligned with the input light coupling unit.

[0029] Optionally, the fiber module is fixed to a preset position of the molecular fluorescence detection chip by bonding with optical coupling glue, or the optical fiber module is fixed to a preset position of the molecular fluorescence detection chip by bonding.

[0030] Optionally, the optical fiber module includes a base, a cover plate and one or more optical fibers, one side of the base is provided with a single V-groove or multiple V-grooves arranged side by side and at intervals, the optical fiber is located in the V-groove, and the cover plate is arranged opposite to the base to cover the V-groove.

[0031] Optionally, the input light coupling unit adopts an edge coupler, the initial direction of the pigtail of the optical fiber module is parallel to the plane where the molecular fluorescence detection chip is located, the optical fiber module is fixed to the side of the molecular fluorescence detection chip and the optical input channel of the optical fiber module is aligned with the waveguide core of the edge coupler.

[0032] Optionally, the input light coupling unit includes a grating coupler, and the optical fiber module also includes a glass waveguide device, a first end face of the glass waveguide device is fixedly connected to the sides of the substrate and the cover plate, and a waveguide core of the glass waveguide device is aligned with the optical fiber in the V-groove, an initial direction of the pigtail of the optical fiber module and an extension direction of the waveguide core of the glass waveguide device are parallel to the plane where the molecular fluorescence detection chip is located, the glass waveguide device is fixed above the grating coupler, and a second end face of the glass waveguide device is an inclined surface to serve as a reflection surface to reflect the light entering the glass waveguide device into the grating coupler.

[0033] Optionally, a reflective film is provided on the second end face of the glass waveguide device.

[0034] Optionally, the input light coupling unit adopts a grating coupler, the initial direction of the pigtail of the optical fiber module is not parallel to the plane where the molecular fluorescence detection chip is located, the optical fiber module is fixed to the upper surface of the molecular fluorescence detection chip and the optical input channel of the optical fiber module is aligned with the grating coupler, and the end face polishing angle of the optical fiber module is consistent with the exit angle of the grating coupler.

[0035] As described above, the molecular fluorescence detection chip of the present invention includes a fluorescence detection layer, a fluorescence collection layer and a fluorescence excitation layer arranged in sequence from bottom to top, the fluorescence excitation layer includes an input light coupling module, a light beam splitter tree structure, a fluorescence excitation structure array, a light coupling structure array and a light feedback structure, the input light coupling module includes one or more input light coupling units, and the input end of the light feedback structure is connected to one output end of the light beam splitter tree structure. The optical packaging structure of the present invention includes an optical fiber module and the above-mentioned molecular fluorescence detection chip, the optical fiber module is fixed to a preset position of the molecular fluorescence detection chip and includes one or more light input channels, the light input channels are aligned with the input light coupling unit, this passive light coupling scheme makes the light coupling efficiency not change with the mechanical vibration of the environment, thereby improving the stability of the excitation light in the chip, and thus more conducive to the stability of the fluorescence signal, while also reducing the complexity of the external device optical path, saving equipment costs. In addition, the present invention can use a multi-channel coupling method to increase the number of lasers, thereby increasing the power of the excitation light in the chip, and thus improving the signal-to-noise ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Shown is a structural block diagram of the molecular fluorescence detection chip of the present invention.

[0037] Figure 2 Shown is a planar layout diagram of the fluorescence excitation layer of the molecular fluorescence detection chip of the present invention in one embodiment.

[0038] Figure 3 Shown is a side structural diagram of an optical packaging structure of the present invention in one embodiment.

[0039] Figure 4 It is a schematic diagram of a partial cross-sectional structure of an optical fiber module in the optical packaging structure of the present invention in one embodiment.

[0040] Figure 5 It is a schematic diagram of a top view of a structure in which an input optical coupling unit adopts an edge coupler and is fixedly connected to the optical fiber module by optical coupling glue in one embodiment.

[0041] Figure 6 It is a schematic side view of the structure in which the input optical coupling unit adopts an edge coupler and is fixedly connected to the optical fiber module by optical coupling glue in one embodiment.

[0042] Figure 7 It is a schematic diagram showing that in another embodiment, the input light coupling unit adopts a grating coupler and the optical fiber module includes a glass waveguide device.

[0043] Figure 8 It is a schematic diagram showing that in yet another embodiment, the input light coupling unit adopts a grating coupler and is fixedly connected to the optical fiber module by optical coupling glue.

[0044] Fig. 9 A schematic diagram of the structure showing a Y-branched structure.

[0045] Fig.10 Shown is a schematic diagram of the structure of a 1×2 multimode interference coupler.

[0046] Fig.11 Shown is a schematic diagram of the structure of a 2×2 multimode interference coupler.

[0047] Fig.12 Shown is a schematic diagram of the structure of a 2×2 directional coupler.

[0048] Fig.13 Shown is a schematic diagram of the structure of a 1×5 multimode interference coupler.

[0049] Fig.14 Shown is a schematic diagram of the structure of a 1×3 multimode interference coupler.

[0050] Fig.15 Shown is a schematic diagram of the structure of a 1×N optical beam splitter unit.

[0051] Fig.16 Shown is a schematic side view of a fluorescent excitation structure array in one embodiment.

[0052] Fig.17 Shown is a schematic top view of a fluorescent excitation structure array in one embodiment.

[0053] Fig.18Another schematic side view of the fluorescent excitation structure array in one embodiment is shown.

[0054] Fig.19 Shown is a schematic side view of the fluorescent excitation structure array in another embodiment.

[0055] Fig. 20 Shown is a schematic top view of the structure of a fluorescence excitation structure array in another embodiment.

[0056] Fig.21 Shown is a schematic side view of the fluorescent excitation structure array in yet another embodiment.

[0057] Fig. 22 Shown is a schematic top view of the structure of a fluorescence excitation structure array in yet another embodiment.

[0058] Fig.23 FIG. 4 is a schematic diagram showing a cross-sectional structure of the optical fiber module in one embodiment.

[0059] Description of Reference Numerals

[0060] 1 Molecular fluorescence detection chip

[0061] 101 Fluorescence Excitation Layer

[0062] 1011 Input Optical Coupler Module

[0063] 1011a Edge Coupler

[0064] 1011b Grating Coupler

[0065] 1012 Optical Feedback Structure

[0066] 1012a The first 1×2 optical beam splitter

[0067] 1012b Second 1×2 beam splitter

[0068] 1012c First feedback optical coupling unit

[0069] 1012d Second feedback optical coupling unit

[0070] 1012e Third Feedback Optocoupler

[0071] 1013 Beam Splitter Tree Structure

[0072] 1014 Fluorescence Excitation Structure Array

[0073] 1014a cladding

[0074] 1014b waveguide structure

[0075] 1014b-11 Straight Waveguide

[0076] 1014b-12 grating structure

[0077] 1014b-21 Straight Waveguide

[0078] 1014b-22 V-type metal grating structure

[0079] 1014c Sample Well

[0080] 1015 Optical coupling structure array

[0081] 1016 Optical Power Balance Module

[0082] 102 Fluorescence collection layer

[0083] 103 Fluorescence detection layer

[0084] 104 Base

[0085] 2 Fiber Optic Modules

[0086] 201 Base

[0087] 2011 V-Trough

[0088] 202 Cover

[0089] 203 Fiber Optic

[0090] 204 Input Channel Groups

[0091] 205 First light feedback channel

[0092] 206 Second optical feedback channel

[0093] 207 Glass waveguide devices

[0094] 208 Reflective film

[0095] 3 Optical coupling glue DETAILED DESCRIPTION

[0096] The present invention provides an integrated solution for the detection of fluorescent signals of biological samples, especially the detection of fluorescent signals of gene sequencing. The following describes the implementation of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0097] It should be emphasized that the term “include / comprises” when used herein refers to the presence of features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps or components.

[0098] Features described and / or illustrated with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.

[0099] For example, when describing the embodiments of the present invention in detail, for the sake of convenience, the schematic diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0100] For ease of description, spatially relative terms such as "under", "below", "below", "below", "above", "on", etc. may be used herein to describe the relationship of one element or feature shown in the drawings to other elements or features. It will be understood that these spatially relative terms are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the drawings. In addition, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.

[0101] In the context of the present application, a structure in which a first feature is described as being "above" a second feature may include embodiments in which the first and second features are in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0102] It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and therefore the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0103] See also Figure 1 , which is a structural block diagram of the molecular fluorescence detection chip 1 of the present invention, includes a fluorescence detection layer 103, a fluorescence collection layer 102 and a fluorescence excitation layer 101 arranged in sequence from bottom to top, wherein the fluorescence detection layer 103 can be grown on a substrate 104.

[0104] Specifically, the fluorescence excitation layer 101 is used to excite fluorescence signals, the fluorescence collection layer 102 is used to collect fluorescence signals, and the fluorescence detection layer 103 is used to detect fluorescence signals, wherein the fluorescence collection layer 102 may include a fluorescence filter layer, an aperture layer and a microlens array layer (the specific layout of each component can be arranged according to actual needs, and is not specifically limited in the present invention), and the fluorescence detection layer 103 may select one or more of a CCD chip, a CMOS image sensor chip, a PD array, a SPAD array, a PMT array and a SiPM array.

[0105] For details, please refer to Figure 2 , which is a planar layout diagram of the fluorescence excitation layer 101 , includes an input light coupling module 1011 , a beam splitter tree structure 1013 , a fluorescence excitation structure array 1014 , a light coupling-out structure array 1015 and a light feedback structure 1012 .

[0106] Specifically, the input end of the optical beam splitter tree structure 1013 is connected to the output end of the input light coupling module 1011. It should be noted that the input light coupling module 1011 may include one or more input light coupling units, that is, the molecular fluorescence detection chip 1 may be a single-channel chip or a multi-channel chip. Figure 2 In the illustrated embodiment, the number of input light coupling units of the input light coupling module 1011 is taken as a plurality (e.g., 4). In order to achieve multi-channel power balancing, an optical power balancing module 1016 may be optionally provided in the fluorescence excitation layer 101. The optical power balancing module 1016 is connected between the input light coupling module 1011 and the optical beam splitter tree structure 1013.

[0107] As an example, the optical power balancing module 1016 includes an N×N optical beam combining structure, which is used to combine the power of multiple input lights and then split them, so as to achieve the purpose of N-channel power balancing, wherein N is consistent with the number of input optical coupling units of the input optical coupling module 1011, and the N×N optical beam combining structure includes a 2×2 optical coupler, or includes a plurality of cascaded 2×2 optical couplers, and the 2×2 optical coupler can adopt a directional coupler (Directional Coupler, referred to as DC) or a multimode interferometer coupler (Multimode Interferometer Coupler, referred to as MMI).

[0108] Specifically, the optical beam splitter tree structure 1013 includes multiple output ends, one of which serves as the first output end, and the other multiple output ends serve as the second output end. The input end of the fluorescence excitation structure array 1014 is connected to the second output end of the optical beam splitter tree structure 1013, the input end of the optical coupling-out structure array 1015 is connected to the output end of the fluorescence excitation structure array 1014, and the input end of the optical feedback structure 1012 is connected to the first output end of the optical beam splitter tree structure 1013.

[0109] The functions and structures of each module in the fluorescence excitation layer 101 are described in detail below in conjunction with the optical packaging structure of the molecular fluorescence detection chip 1 .

[0110] As an example, see Figure 3 , shown is a side view structural diagram of the optical packaging structure in an embodiment, including the molecular fluorescence detection chip and the optical fiber module 2, the optical fiber module 2 is fixed at a preset position of the molecular fluorescence detection chip 1 and includes one or more optical input channels, and the optical input channels are aligned with the input light coupling unit, wherein the main function of the optical feedback structure 1012 in the molecular fluorescence detection chip 1 is to provide feedback light when the molecular fluorescence detection chip 1 is coupled with the optical fiber module 2, so as to optimize the alignment, and in addition, the optical feedback structure 1012 can also be used for the calibration of chip insertion loss.

[0111] In some embodiments, for example Figure 3 As shown, the optical fiber module 2 is bonded and fixed to the preset position of the molecular fluorescence detection chip 1 by optical coupling glue 3. In other embodiments, the optical fiber module 2 can also be fixed to the preset position of the molecular fluorescence detection chip 1 by bonding.

[0112] Specifically, the passive optical coupling scheme adopted by the optical packaging structure can ensure that the optical coupling efficiency does not change with the environmental mechanical vibration, which is beneficial to improving the stability of the excitation light within the chip, and thus to the stability of the fluorescence signal. It also reduces the complexity of the optical path of the external device and helps save equipment costs.

[0113] Specifically, when the number of the input light coupling units is one, the optical fiber module 2 correspondingly includes one optical input channel, and when the number of the input light coupling units is multiple, the optical fiber module 2 also correspondingly includes multiple optical input channels. At this time, the multiple input light coupling units form an array with a fixed spacing perpendicular to the light propagation direction, and the input channel spacing of the optical fiber module 2 is the same as the spacing of the input light coupling unit array.

[0114] In some embodiments, the optical fiber module 2 preferably uses multiple optical input channels to increase the number of lasers through multi-channel coupling, thereby increasing the on-chip excitation light power and further improving the signal-to-noise ratio.

[0115] Specifically, when the optical feedback structure 1012 adopts an optical fiber module feedback solution (which will be described in detail in the relevant parts later), the optical fiber module 2 further includes a first optical feedback channel and a second optical feedback channel.

[0116] Specifically, each of the optical input channels is aligned with a corresponding input optical coupling unit, and each of the optical feedback channels is aligned with a corresponding feedback optical coupling unit.

[0117] Specifically, the function of the optical fiber module 2 is to fix the bare optical fiber so that it can be connected to the chip, thereby coupling the input light into the chip, or receiving the feedback light from the chip, see Figure 4 , shown is a schematic diagram of a partial cross-sectional structure of the optical fiber module 2 in an embodiment, including a base 201, a cover plate 202 and one or more optical fibers 203, one side of the base 201 is provided with a single V-groove 2011 or multiple V-grooves 2011 arranged side by side and at intervals, the optical fiber 203 is located in the V-groove 2011, and the cover plate 202 is arranged opposite to the base 201 to cover the V-groove 2011.

[0118] Specifically, the optical fiber module 2 includes one or more input optical fibers (corresponding to one or more optical input channels), and optionally includes two feedback optical fibers (corresponding to a first optical feedback channel and a second optical feedback channel, respectively), wherein the input optical fiber and the feedback optical fiber are respectively accommodated in the corresponding V-groove 2011.

[0119] Specifically, in the input light coupling module 1011, the input light coupling unit can be in various forms. For example, see Figure 5 and Figure 6 , which is a schematic diagram showing that in one embodiment, the input optical coupling unit uses an edge coupler 1011a and is fixedly connected to the optical fiber module 2 through an optical coupling glue 3, wherein: Figure 5 is a top view, Figure 6 It is a side view, the initial direction of the fiber pigtail of the optical fiber module 2 is parallel to the plane where the molecular fluorescence detection chip 1 is located, the optical fiber module 2 is fixed to the side of the molecular fluorescence detection chip 1 and the optical input channel of the optical fiber module 2 is aligned with the waveguide core of the edge coupler 1011a.

[0120] As an example, see Figure 7, showing a schematic diagram of another embodiment in which the input light coupling unit adopts a grating coupler 1011b and the optical fiber module 2 further includes a glass waveguide device 207, wherein the first end face of the glass waveguide device 207 is fixedly connected to the sides of the substrate and the cover plate and the waveguide core of the glass waveguide device 207 is aligned with the optical fiber in the V-groove, the initial direction of the pigtail of the optical fiber module 2 and the extension direction of the waveguide core of the glass waveguide device 207 are parallel to the plane where the molecular fluorescence detection chip 1 is located, the glass waveguide device 207 is fixed above the grating coupler 1011b, and the second end face of the glass waveguide device 207 is an inclined surface to serve as a reflection surface to reflect the light entering the glass waveguide device 207 into the grating coupler 1011b.

[0121] Specifically, the glass waveguide device 207 is a type of planar optical waveguide device (PLC device). In this embodiment, the first end face of the glass waveguide device 207 is fixedly connected to the sides of the substrate and the cover plate through optical coupling glue 3, and the bottom surface of the glass waveguide device 207 is fixed above the grating coupler 1011b through optical coupling glue 3.

[0122] As an example, the angle between the second end surface of the glass waveguide device 207 and the bottom surface of the glass waveguide device 207 is in the range of 35° to 50°.

[0123] In some embodiments, the second end surface of the glass waveguide device 207 may be optionally provided with a reflective film 208, such as a metal coating, to increase reflectivity.

[0124] As an example, see Figure 8 , showing a schematic diagram of another embodiment in which the input light coupling unit adopts a grating coupler 1011b and is fixedly connected to the optical fiber module 2 by an optical coupling glue 3, wherein the initial direction of the pigtail of the optical fiber module 2 is not parallel to the plane where the molecular fluorescence detection chip is located (for example, close to vertical), the optical fiber module 2 is fixed to the upper surface of the molecular fluorescence detection chip 1 and the optical input channel of the optical fiber module 2 is aligned with the grating coupler 1011b, and the end face polishing angle of the optical fiber module 2 is consistent with the exit angle of the grating coupler 1011b.

[0125] Specifically, the beam splitter tree structure 1013 is used to split a single light path into multiple branches to facilitate the subsequent expansion of fluorescence excitation points.

[0126] As an example, the beam splitter tree structure 1013 includes one or more beam splitter units, such as Figure 2The 1×N optical beam splitter unit includes four 1×N optical beam splitter units, and the beam splitting characteristic of the 1×N optical beam splitter unit is to split one input light into N beams of light output, and each beam has the same splitting ratio.

[0127] As an example, the optical beam splitter unit selects one of a Y-branch structure, a 2×2 directional coupler, a 1×2 multimode interference coupler, a 2×2 multimode interference coupler, a 1×3 multimode interference coupler and a 1×5 multimode interference coupler, or is composed of a cascade of multiple thereof (1×N optical beam splitter unit).

[0128] As an example, see Figures 9 to 15 , showing various exemplary structures of the optical beam splitter unit, wherein, Fig. 9 A schematic diagram showing a Y-branched structure. Fig.10 Shown is a schematic diagram of the structure of a 1×2 multimode interference coupler. Fig.11 Shown is a schematic diagram of the structure of a 2×2 multimode interference coupler. Fig.12 Shown is a schematic diagram of the structure of a 2×2 directional coupler. Fig.13 Shown is a schematic diagram of the structure of a 1×5 multimode interference coupler. Fig.14 Shown is a schematic diagram of the structure of a 1×3 multimode interference coupler. Fig.15 Shown is a schematic diagram of the structure of a 1×N optical beam splitter unit.

[0129] Specifically, the function of the fluorescent excitation structure array 1014 is to achieve the excitation of fluorescent molecules by physically limiting the fluorescent molecules and designing the evanescent wave mode field, thereby generating fluorescent radiation.

[0130] As an example, see Fig.16 , Fig.17 and Fig.18 , which is a schematic diagram of the structure of the fluorescence excitation structure array 1014 in one embodiment, wherein: Fig.16 is a side view, Fig.17 is a top view (the cladding is omitted), Fig.18 The fluorescence excitation structure array 1014 includes a cladding 1014a and one or more waveguide structures 1014b coated in the cladding 1014a. The surface of the cladding 1014a above the waveguide structure 1014b is provided with sample wells 1014c arranged at a certain period along the waveguide propagation direction. The sample wells 1014c are used to load molecular substances that can excite fluorescence. The distance between the bottom surface of the sample well 1014c and the top surface of the waveguide structure 1014b is less than the waveguide evanescent wave penetration distance.

[0131] As an example, the waveguide structure 1014b adopts a straight waveguide, and the sample well 1014c is located directly above the straight waveguide.

[0132] As an example, the sample well 1014c may be in the shape of a cylinder, a truncated cone, a cuboid or other suitable shapes, and the size (eg, diameter, side length, etc.) of the sample well 1014c may be in the order of tens to hundreds of nanometers.

[0133] As an example, the fluorescent molecules are fixed to the bottom of the sample well 1014c by a chemical surface modification method, so as to be excited by the waveguide evanescent wave light field and generate fluorescent signals.

[0134] As an example, see Fig.19 and Fig. 20 , which is a schematic diagram of the structure of the fluorescence excitation structure array 1014 in another embodiment, wherein: Fig.19 is a side view, Fig. 20 It is a top view (cladding omitted), the waveguide structure 1014b includes a straight waveguide 1014b-11 and a plurality of grating structures 1014b-12 located on one side of the straight waveguide 1014b-11 and connected to the straight waveguide 1014b-1, and the sample well 1014c is located directly above the grating structure 1014b-12.

[0135] See also Fig.21 and Fig. 22 , which is a schematic diagram of the structure of the fluorescence excitation structure array 1014 in another embodiment, wherein: Fig.21 is a side view, Fig. 22 It is a top view (with the cladding omitted), the waveguide structure 1014b includes a straight waveguide 1014b-21 and a V-shaped metal grating structure 1014b-22 located on the straight waveguide 1014b-21, and the sample well 1014c is located directly above the V-shaped metal grating structure 1014b-22.

[0136] Specifically, the function of the optical coupling structure array 1015 is to couple the remaining excitation light after passing through the fluorescent excitation structure array 1014 out of the chip. This can prevent the light from being reflected inside the chip, thereby forming a standing wave distribution in the fluorescent excitation structure array 1014, resulting in uneven distribution of the excitation light field.

[0137] As an example, the light out-coupling structure array 1015 includes a plurality of light out-coupling units, and each of the light out-coupling units is correspondingly connected to one output end of the fluorescence excitation structure array 1014 .

[0138] As an example, the optical coupling unit adopts a grating coupler, and its 3dB line width is greater than 10nm.

[0139] Specifically, as mentioned above, a main function of the optical feedback structure 1012 is to provide feedback light when the molecular fluorescence detection chip 1 is coupled with the optical fiber module 2, so as to optimize alignment.

[0140] In some embodiments, the optical feedback structure 1012 adopts an optical fiber module optical feedback solution, including a 1×2 optical beam splitter, a first feedback optical coupling unit and a second feedback optical coupling unit, wherein the first feedback optical coupling unit and the second feedback optical coupling unit realize optical feedback by coupling feedback light into the optical feedback channel of the optical fiber module 2, wherein the input optical coupling module 1011 is located between the first feedback optical coupling unit and the second feedback optical coupling unit, the first feedback optical coupling unit, the input optical coupling unit and the second feedback optical coupling unit are arranged in a straight line at equal intervals perpendicular to the light propagation direction, and the input end of the 1×2 optical beam splitter is connected to one output end of the optical beam splitter tree structure ( The first feedback optical coupling unit is connected to the first output end of the 1×2 optical beam splitter, and the input end of the second feedback optical coupling unit is connected to the second output end of the 1×2 optical beam splitter; the output end of the first feedback optical coupling unit, the input end of the input optical coupling unit, and the output end of the second feedback optical coupling unit are all used to connect to the optical fiber module, and the optical fiber module includes a first optical feedback channel, an optical input channel, and a second optical feedback channel arranged side by side, the output end of the first feedback optical coupling unit is connected to the first optical feedback channel, the input end of the input optical coupling unit is connected to the optical input channel, and the output end of the second feedback optical coupling unit is connected to the second optical feedback channel.

[0141] As an example, the emission angle range of the first feedback light coupling unit and the second feedback light coupling unit is 8 to 10 degrees, and the near-field spot diameter range is 3 to 5 microns.

[0142] In other embodiments, the optical feedback structure 1012 adopts a spatial optical feedback solution, including a feedback optical coupling unit, wherein the input end of the feedback optical coupling unit is connected to one output end of the optical beam splitter tree structure, and the output end of the feedback optical coupling unit is connected to an off-chip optical system, and the output light spot is collected by the off-chip optical system in free space.

[0143] As an example, the output angle range of the feedback light coupling unit is 30 to 60 degrees, the near-field light spot diameter range is 30 to 60 microns, and the output light spot is collected by the off-chip optical system in free space.

[0144] In some other embodiments, the optical feedback structure 1012 can reuse the above two optical feedback schemes, and one of them can be selected for use according to needs, or used simultaneously. For example, when the number of channels of the molecular fluorescence detection chip 1 is large, it is preferred to use the optical fiber module optical feedback scheme, and the spatial optical feedback scheme can be optionally used for assistance, and when the number of channels of the molecular fluorescence detection chip 1 is small, for example, when the molecular fluorescence detection chip 1 adopts a single channel or a dual channel, only the spatial optical feedback scheme can be used.

[0145] As an example, in Figure 3 In the illustrated embodiment, the optical feedback structure 1012 includes both of the above-mentioned two optical feedback schemes, including a first 1×2 optical beam splitter 1012a, a second 1×2 optical beam splitter 1012b, a first feedback optical coupling unit 1012c, a second feedback optical coupling unit 1012d and a third feedback optical coupler 1012e, the input optical coupling module 1011 is located between the first feedback optical coupling unit 1012c and the second feedback optical coupling unit 1012d, the first feedback optical coupling unit 1012c, the input optical coupling unit and the second feedback optical coupling unit 1012d are arranged in a straight line at equal intervals perpendicular to the light propagation direction, the input end of the first 1×2 optical beam splitter 1012a is connected to the first output end of the optical beam splitter tree structure 1013, the input end of the second 1×2 optical beam splitter 1012b is connected to the first output end of the first 1×2 optical beam splitter 1012a, and the input end of the first feedback optical coupling unit 1012c is connected to the first output end of the first 1×2 optical beam splitter 1012a. The first output end of the second 1×2 optical beam splitter 1012b is connected, the input end of the second feedback optical coupling unit 1012d is connected to the second output end of the second 1×2 optical beam splitter 1012d, and the input end of the third feedback optical coupling unit 1012e is connected to the second output end of the first 1×2 optical beam splitter 1012a; the output end of the first feedback optical coupling unit 1012c, the input end of the input optical coupling unit and the output end of the second feedback optical coupling unit 1012d are all used to connect to an optical fiber module, and the optical fiber module includes a first optical feedback channel, an optical input channel and a second optical feedback channel arranged side by side, the output end of the first feedback optical coupling unit 1012c is connected to the first optical feedback channel, the input end of the input optical coupling unit is connected to the optical input channel, the output end of the second feedback optical coupling unit 1012d is connected to the second optical feedback channel, and the output end of the third feedback optical coupling unit 1012e is connected to an off-chip optical system.

[0146] As an example, see Fig.23, which is a schematic diagram of the cross-sectional structure of the optical fiber module 2 in one embodiment, includes an input channel group 204 (taking 4 input channels as an example) and a first optical feedback channel 205 and a second optical feedback channel 206 distributed on both sides of the input channel group 204.

[0147] As an example, during the packaging process, the optical fiber module 2 is clamped and fixed on a translation table (e.g., a 6-axis translation table), and the molecular fluorescence detection chip 1 is fixed on the platform. The alignment position is preliminarily determined with the assistance of a camera. After the light feedback structure 1012 emits light, the optical fiber module 2 is aligned with the molecular fluorescence detection chip 1 by adjusting the translation table, and after alignment, they are coupled using UV glue or bonding.

[0148] Specifically, for the optical feedback solution of the optical fiber module, the optical feedback channel of the optical fiber module 2 is connected to the photodiode (PD), and the optical fiber module 2 is displaced by adjusting the displacement stage so that the readings of the photodiodes on both sides reach the optimal value at the same time. At this time, it means that the optical fiber module 2 has reached the optimal position and is aligned with the molecular fluorescence detection chip 1.

[0149] Specifically, for the spatial light feedback solution, the optical fiber module 2 is also displaced by adjusting the displacement stage so that the reading of the photodiode of the off-chip optical system is maximized. At this time, it means that the optical fiber module 2 reaches the optimal position and is aligned with the molecular fluorescence detection chip 1.

[0150] As an example, the emission angle range of the first feedback light coupling unit 1012c and the second feedback light coupling unit 1012d is 8 to 10 degrees, and the near-field spot diameter range is 3 to 5 microns. A smaller emission angle facilitates coupling with the optical fiber module 2.

[0151] As an example, the emission angle range of the third feedback light coupling unit is 30 to 60 degrees, and the near-field spot diameter range is 30 to 60 microns. A larger emission angle is convenient for spatial light feedback, and oblique emission is helpful for avoiding obstacles.

[0152] Specifically, in addition to assisting alignment during optical packaging, the optical feedback structure 1012 can also provide the following functions during the use phase:

[0153] (1)Chip polarization state calibration;

[0154] (2) On-chip optical power monitoring: Check whether the initial optical power is abnormal. For example, check whether the chip is damaged during storage and transportation (often difficult to detect with the naked eye), resulting in a decrease in the on-chip light intensity, or whether an accident occurs during use, resulting in a decrease in the on-chip light intensity.

[0155] In summary, the molecular fluorescence detection chip of the present invention includes a fluorescence detection layer, a fluorescence collection layer and a fluorescence excitation layer arranged in sequence from bottom to top, the fluorescence excitation layer includes an input light coupling module, a light beam splitter tree structure, a fluorescence excitation structure array, a light coupling structure array and a light feedback structure, the input light coupling module includes one or more input light coupling units, and the input end of the light feedback structure is connected to one output end of the light beam splitter tree structure. The optical packaging structure of the present invention includes an optical fiber module and the above-mentioned molecular fluorescence detection chip, the optical fiber module is fixed to a preset position of the molecular fluorescence detection chip and includes one or more light input channels, the light input channels are aligned with the input light coupling unit, this passive light coupling scheme makes the light coupling efficiency not change with the mechanical vibration of the environment, thereby improving the stability of the excitation light in the chip, and thus more conducive to the stability of the fluorescence signal, while also reducing the complexity of the external device optical path, saving equipment costs. In addition, the present invention can adopt a multi-channel coupling method to increase the number of lasers, thereby increasing the excitation light power in the chip, and thus improving the signal-to-noise ratio. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has a high industrial utilization value.

[0156] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A molecular fluorescence detection chip, characterized in that: It includes a fluorescence detection layer, a fluorescence collection layer and a fluorescence excitation layer arranged in sequence from bottom to top, and the fluorescence excitation layer includes: An input light coupling module, wherein the input light coupling module comprises one or more input light coupling units; An optical beam splitter tree structure, wherein the input end of the optical beam splitter tree structure is connected to the output end of the input optical coupling module, and the optical beam splitter tree structure comprises a first output end and multiple second output ends; A fluorescence excitation structure array, wherein an input end of the fluorescence excitation structure array is connected to a second output end of the optical beam splitter tree structure; An optical coupling-out structure array, wherein an input end of the optical coupling-out structure array is connected to an output end of the fluorescence excitation structure array; An optical feedback structure, wherein an input end of the optical feedback structure is connected to a first output end of the optical beam splitter tree structure.

2. The molecular fluorescence detection chip according to claim 1, characterized in that: The input light coupling module includes a plurality of input light coupling units, and the fluorescence excitation layer further includes an optical power balancing module, which is connected between the input light coupling module and the optical beam splitter tree structure.

3. The molecular fluorescence detection chip according to claim 2, characterized in that: The optical power balancing module includes an N×N optical beam combining structure, wherein N is consistent with the number of the input optical coupling units, and the N×N optical beam combining structure includes a 2×2 optical coupler, or includes a plurality of cascaded 2×2 optical couplers, and the 2×2 optical coupler adopts a directional coupler or a multimode interference coupler.

4. The molecular fluorescence detection chip according to claim 1, characterized in that: The optical feedback structure includes a 1×2 optical beam splitter, a first feedback optical coupling unit and a second feedback optical coupling unit, the input optical coupling module is located between the first feedback optical coupling unit and the second feedback optical coupling unit, the first feedback optical coupling unit, the input optical coupling unit and the second feedback optical coupling unit are arranged in a straight line at equal intervals perpendicular to the light propagation direction, the input end of the 1×2 optical beam splitter is connected to the first output end of the optical beam splitter tree structure, the input end of the first feedback optical coupling unit is connected to the first output end of the 1×2 optical beam splitter, and the input end of the second feedback optical coupling unit is connected to the second output end of the 1×2 optical beam splitter; The output end of the first feedback optical coupling unit, the input end of the input optical coupling unit, and the output end of the second feedback optical coupling unit are all used to connect to an optical fiber module, the optical fiber module includes a first optical feedback channel, an optical input channel, and a second optical feedback channel arranged side by side, the output end of the first feedback optical coupling unit is connected to the first optical feedback channel, the input end of the input optical coupling unit is connected to the optical input channel, and the output end of the second feedback optical coupling unit is connected to the second optical feedback channel.

5. The molecular fluorescence detection chip according to claim 4, characterized in that: The emission angle range of the first feedback light coupling unit and the second feedback light coupling unit is 8 to 10 degrees, and the near-field light spot diameter range is 3 to 5 microns.

6. The molecular fluorescence detection chip according to claim 1, characterized in that: The optical feedback structure comprises a feedback optical coupling unit, the input end of the feedback optical coupling unit is connected to the first output end of the optical beam splitter tree structure, and the output end of the feedback optical coupling unit is used to connect to an off-chip optical system.

7. The molecular fluorescence detection chip according to claim 6, characterized in that: The output angle range of the feedback light coupling unit is 30 to 60 degrees, the diameter range of the near-field light spot is 30 to 60 microns, and the output light spot is collected by the off-chip optical system in free space.

8. The molecular fluorescence detection chip according to claim 1, characterized in that: The optical feedback structure includes a first 1×2 optical beam splitter, a second 1×2 optical beam splitter, a first feedback optical coupling unit, a second feedback optical coupling unit and a third feedback optical coupler, the input optical coupling module is located between the first feedback optical coupling unit and the second feedback optical coupling unit, the first feedback optical coupling unit, the input optical coupling unit and the second feedback optical coupling unit are arranged in a straight line at equal intervals perpendicular to the light propagation direction, the input end of the first 1×2 optical beam splitter is connected to the first output end of the optical beam splitter tree structure, the input end of the second 1×2 optical beam splitter is connected to the first output end of the first 1×2 optical beam splitter, the input end of the first feedback optical coupling unit is connected to the first output end of the second 1×2 optical beam splitter, the input end of the second feedback optical coupling unit is connected to the second output end of the second 1×2 optical beam splitter, and the input end of the third feedback optical coupling unit is connected to the second output end of the first 1×2 optical beam splitter; The output end of the first feedback optical coupling unit, the input end of the input optical coupling unit, and the output end of the second feedback optical coupling unit are all used to connect to an optical fiber module, the optical fiber module includes a first optical feedback channel, an optical input channel, and a second optical feedback channel arranged side by side, the output end of the first feedback optical coupling unit is connected to the first optical feedback channel, the input end of the input optical coupling unit is connected to the optical input channel, and the output end of the second feedback optical coupling unit is connected to the second optical feedback channel; The output end of the third feedback light coupling unit is used to connect to an off-chip optical system.

9. The molecular fluorescence detection chip according to claim 8, characterized in that: The emission angle range of the first feedback light coupling unit and the second feedback light coupling unit is 8 to 10 degrees, and the near-field spot diameter range is 3 to 5 microns; the emission angle range of the third feedback light coupling unit is 30 to 60 degrees, and the near-field spot diameter range is 30 to 60 microns, and the emission spot is collected by the off-chip optical system in free space.

10. The molecular fluorescence detection chip according to claim 1, characterized in that: The optical beam splitter tree structure includes one or more optical beam splitter units, and the optical beam splitter units include one or more of a Y-branch structure, a 2×2 directional coupler, a 1×2 multimode interference coupler, a 2×2 multimode interference coupler, a 1×3 multimode interference coupler and a 1×5 multimode interference coupler.

11. The molecular fluorescence detection chip according to claim 1, characterized in that: The fluorescence excitation structure array includes a cladding and one or more waveguide structures coated in the cladding. The surface of the cladding above the waveguide structure is provided with sample wells arranged at a certain period along the waveguide propagation direction. The sample wells are used to load molecular substances that can excite fluorescence. The distance between the bottom surface of the sample well and the top surface of the waveguide structure is less than the evanescent wave penetration distance of the waveguide structure.

12. The molecular fluorescence detection chip according to claim 11, characterized in that: The waveguide structure adopts a straight waveguide, and the sample well is located directly above the straight waveguide; or the waveguide structure includes a straight waveguide and a plurality of grating structures located on one side of the straight waveguide and connected to the straight waveguide, and the sample well is located directly above the grating structure; or the waveguide structure includes a straight waveguide and a V-shaped metal grating structure located on the straight waveguide, and the sample well is located directly above the V-shaped metal grating structure.

13. The molecular fluorescence detection chip according to claim 1, characterized in that: The optical outcoupling structure array includes a plurality of optical outcoupling units, and the optical outcoupling units adopt grating couplers.

14. The molecular fluorescence detection chip according to claim 1, characterized in that: The fluorescence collection layer includes a fluorescence filter layer, an aperture layer and a microlens array layer.

15. The molecular fluorescence detection chip according to claim 1, characterized in that: The fluorescence detection layer includes one or more of a CCD chip, a CMOS image sensor chip, a PD array, a SPAD array, a PMT array and a SiPM array.

16. An optical packaging structure, characterized in that: It comprises an optical fiber module and a molecular fluorescence detection chip as described in any one of claims 1 to 15, wherein the optical fiber module is fixed at a preset position of the molecular fluorescence detection chip, and the optical fiber module comprises one or more optical input channels, and the optical input channels are aligned with the input light coupling unit.

17. The optical packaging structure according to claim 16, characterized in that: The fiber module is fixed to the preset position of the molecular fluorescence detection chip by bonding with optical coupling glue, or the optical fiber module is fixed to the preset position of the molecular fluorescence detection chip by bonding.

18. The optical packaging structure according to claim 16, characterized in that: The optical fiber module includes a base, a cover plate and one or more optical fibers. One side of the base is provided with a single V-groove or multiple V-grooves arranged side by side and at intervals. The optical fiber is located in the V-groove. The cover plate is arranged opposite to the base to cover the V-groove.

19. The optical packaging structure according to claim 16, wherein: The input light coupling unit adopts an edge coupler, the initial direction of the fiber pigtail of the optical fiber module is parallel to the plane where the molecular fluorescence detection chip is located, the optical fiber module is fixed to the side of the molecular fluorescence detection chip and the optical input channel of the optical fiber module is aligned with the waveguide core of the edge coupler.

20. The optical packaging structure according to claim 16, characterized in that: The input light coupling unit includes a grating coupler, and the optical fiber module also includes a glass waveguide device. The first end face of the glass waveguide device is fixedly connected to the sides of the substrate and the cover plate, and the waveguide core of the glass waveguide device is aligned with the optical fiber in the V-groove. The initial direction of the pigtail of the optical fiber module and the extension direction of the waveguide core of the glass waveguide device are parallel to the plane where the molecular fluorescence detection chip is located. The glass waveguide device is fixed above the grating coupler, and the second end face of the glass waveguide device is an inclined surface to serve as a reflection surface to reflect the light entering the glass waveguide device into the grating coupler.

21. The optical packaging structure according to claim 20, characterized in that: The second end surface of the glass waveguide device is provided with a reflective film.

22. The optical packaging structure according to claim 16, characterized in that: The input light coupling unit adopts a grating coupler, the initial direction of the pigtail of the optical fiber module is not parallel to the plane where the molecular fluorescence detection chip is located, the optical fiber module is fixed to the upper surface of the molecular fluorescence detection chip and the optical input channel of the optical fiber module is aligned with the grating coupler, and the end face polishing angle of the optical fiber module is consistent with the exit angle of the grating coupler.

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