Optical fiber array chip and preparation method thereof

Abstract

The invention discloses an optical fiber array chip and a preparation method thereof, the optical fiber array chip is provided with a plurality of light transmitting needles arranged in a parallel linear array shape or a staggered linear array shape, and the preparation method of the optical fiber array chip comprises a) primary etching, b) primary film forming, c) upper film removing, d) secondary film forming, e) secondary etching, f) lower film removing, g) optical fiber connection and h) packaging. The micro-scale or nano-scale single-dimensional or multi-dimensional linear optical fiber array matrix can be manufactured in a large scale at low cost, and the single or multiple light transmitting needles in the dot matrix light can be used as an emission light source or a collection light window and can also be independently controlled, so that the requirements of current multi-point spectral measurement and optical fiber linear arrays are met.

Description

Technical Field

[0001] The present invention relates to the technical field of optical engineering, in particular to the technical field of optical fiber array chips. Background Art

[0002] Spectrometry is a basic optical measurement technology. The working principle of a spectrometer is to collect the radiation, reflected or transmitted light signals of the target object through the spectral power distribution curve of the incident light, and after optical and electrical signal processing, analyze the structure or composition of the measured substance and the optical properties of the material. It has been widely used in scientific research, industrial testing and medical diagnosis. However, a spectrometer can usually only obtain the spectral information of one position of the target at a time (if the spectral information of multiple positions of the target is to be obtained, multiple realignments are required).

[0003] Imaging spectrometers can simultaneously acquire spatial and spectral information of a target object, forming a multidimensional data set with spatial and spectral resolution; however, the spatial scanning or spectral scanning method of imaging spectrometers limits their efficiency, making it difficult to achieve fast real-time measurements.

[0004] Multi-point spectral measurement is a technology that can perform spectral analysis on multiple spatial locations (i.e., multiple points) at the same time; it combines spectral analysis with multi-point acquisition capabilities, and is used to measure and compare the spectral information of multiple samples, samples at different locations, or multiple parts of a sample at the same time; fiber optic linear array technology is an advanced technology that uses multiple optical fibers arranged in an array to achieve efficient optical signal transmission and processing; by arranging the optical fibers into a specific linear or two-dimensional array structure, the distribution, convergence or regulation of optical signals can be achieved; fiber optic linear array technology has been widely used in communications, sensing, lasers, imaging and other fields, especially laser printing direct writing technology.

[0005] The core challenge of fiber optic linear array technology lies in the precise arrangement and coupling control of accurate optical fibers, which requires advanced micro-nano processing technology and optical design support; however, existing fiber optic linear arrays mainly use silicon V-groove processing, fusion and UV glue fixation, such as a fiber optic array positioning component with publication number CN102692683A, a fiber optic array manufacturing method with announcement number CN104238030B and a novel high-precision fiber optic array manufacturing method with announcement number CN100449343C. It is often difficult to achieve the requirements of precise arrangement and needs to be solved urgently. Summary of the invention

[0006] The purpose of the present invention is to solve the problems in the prior art and to propose an optical fiber array chip for spectral measurement and a micro-nano preparation method thereof, which can manufacture micron-level or nano-level single-dimensional or multi-dimensional linear optical fiber array matrices at low cost and on a large scale according to the size required by the application, and a single or multiple light-transmitting needles in the array light can not only be used as an emitting light source or a collecting light window but can also be individually controlled, thereby meeting the current needs of multi-point spectral measurement and optical fiber linear arrays.

[0007] To achieve the above object, the present invention proposes an optical fiber array chip having a plurality of light-transmitting needles arranged in a parallel linear array or a staggered linear array.

[0008] The method for preparing the optical fiber array chip comprises the following steps: a) One-time etching: etching a number of concave parts on the top surface of the substrate; b) One-time film formation: adopt scheme 1 or scheme 2; The first solution is to form a light-transmitting film on the top surface of the substrate and fill each inner concave portion with the light-transmitting film to form a corresponding light-transmitting needle; The second scheme is to first generate an optical reflective film on the top surface of the substrate and deposit the optical reflective film on the surface of each inner concave portion to form a corresponding lower convex portion, and then generate a light-transmitting film on the top surface of the optical reflective film and fill each lower convex portion with the light-transmitting film to form a corresponding light-transmitting needle; c) Film removal: removing the light-transmitting film except for the light-transmitting needles; d) Secondary film formation: generating a limiting film on the top surface of the substrate or the optical reflective film and making the limiting film cover all the light-transmitting needles at the same time; e) Secondary etching: etching limiting holes connected to each light-transmitting needle on the top surface of the limiting film; f) Lower film removal: remove part of the substrate from bottom to top until the bottom of each light-transmitting needle is exposed; g) Connecting optical fibers: Connect optical fibers to the top of each light-transmitting needle; h) Packaging: Only the top surface of the limiting film is packaged or the top surface of the limiting film and the bottom surface of the substrate are packaged at the same time. The packaging is achieved on the top surface of the limiting film through an upper packaging sheet with several upper packaging holes, and each optical fiber is extended into the corresponding upper packaging hole respectively. The packaging is achieved on the bottom surface of the substrate through a lower packaging sheet that covers each light-transmitting needle at the same time.

[0009] Preferably, each of the inner recesses is in an inverted cone shape.

[0010] Preferably, the substrate is a metal base when using Scheme 1 and a silicon-based inorganic non-metal base when using Scheme 2; for Scheme 2, when adding an optical reflective film, on the one hand, the substrate can not only use a low-cost base material (such as inorganic glass, etc.), but also can adjust the optical properties by modulating the base material, and on the other hand, the optical reflective film can also stop the removal of the light-transmitting film in step c).

[0011] Furthermore, the metal base liner is an aluminum base liner, a stainless steel base liner, a titanium base liner or a tungsten base liner.

[0012] Furthermore, the diameter of the metal substrate is 6 to 12 inches.

[0013] Furthermore, the diameter of the metal substrate is 8 inches.

[0014] Furthermore, the silicon-based inorganic non-metallic substrate is a single crystal silicon wafer, a polycrystalline silicon wafer or a silicon carbide wafer; wherein the polycrystalline silicon material has the advantages of low price and high melting point.

[0015] Furthermore, the diameter of the silicon-based inorganic non-metallic substrate is 6 to 12 inches.

[0016] Furthermore, the diameter of the silicon-based inorganic non-metallic substrate is 8 inches.

[0017] Preferably, the light-transmitting film is a silica glass film, and the optical fiber is made of silica glass.

[0018] Preferably, the limiting film is a metal film or a silicon-based inorganic non-metallic film; wherein the metal material or the silicon-based inorganic non-metallic limiting film can limit the fusion region of the optical fiber.

[0019] Furthermore, the metal film is an aluminum film, a titanium film or a tungsten film, and the silicon-based inorganic non-metallic film is a silicon film or a silicon nitride film.

[0020] Preferably, the optical reflective film is a metal film; wherein the optical reflective film made of metal material can assist in optical reflection.

[0021] Furthermore, the metal film is a tungsten film.

[0022] Preferably, the thickness of the limiting film is 0.1-50 μm, the diameter of each of the optical fibers is 1-100 μm, and the thickness of the optical reflective film is 0.1-10 μm.

[0023] Preferably, the upper packaging sheet is made of an organic polymer packaging material or an inorganic ceramic packaging material, and the lower packaging sheet is a transparent film (ie, the optical window end is protected by a transparent film).

[0024] Preferably, the light-transmitting film, the limiting film and the optical reflective film are all formed by deposition through chemical vapor deposition (CVD) technology, the steps a) and e) both use photoresist etching technology or maskless laser etching technology to complete the etching operation, and the steps c) and f) use mechanical polishing or chemical mechanical polishing (CMP) technology to complete the film removal operation; wherein, for the optical reflective film, the chemical vapor deposition technology can make the tungsten film grow uniformly on the inner wall of the lower convex portion.

[0025] Furthermore, the light-transmitting film is deposited by PECVD or LPCVD technology.

[0026] Furthermore, the light-transmitting film is simultaneously subjected to a vapor phase doping treatment during the chemical vapor deposition treatment, and the light-transmitting film is further subjected to a high-temperature annealing treatment after completing the chemical vapor deposition treatment; wherein, the vapor phase doping treatment can assist in regulating the refractive index of the light-transmitting film (the refractive index of the light-transmitting film can be controlled within a range of 1.4 to 3.5 according to application requirements, thereby matching the refractive index of the optical fiber to reduce the loss of transmitted light); during the vapor phase doping treatment, a small amount of elements such as germanium, phosphorus, boron, erbium, ytterbium and thulium can be added as dopants or to form compound glass (such as strontium titanate glass, fluoride glass and chalcogenide glass, etc.); in addition, the high-temperature annealing treatment can reduce defects inside the glass.

[0027] Beneficial effects of the present invention: 1) The present invention uses a common production process in micron-level integrated circuit production technology to perform multiple film formation and etching operations on a 6-12 inch substrate, and can manufacture micron-level optical fiber array chips according to the size required by the application. Not only is the overall preparation process simple, mature, stable and low-cost, but it can also realize the integrated manufacturing of systems such as beam focusing and detection; 2) The present invention can accurately control the window size and accuracy of the optical emission or detection end by adopting the integrated circuit production process and its equipment, and the deviation distribution (CV) of the window size and accuracy can reach the standard of ≤3%; 3) The present invention etches the substrate and each film layer by using photoresist etching technology or maskless laser etching technology, and can achieve high-density optical window distribution by adjusting the etching area, duration and number (if the diameter of each window is 10μm and the window spacing is 10μm, the optical window density of the dot matrix exceeds 25,000 / cm2); 4) In the fiber array chip prepared by the present invention, each optical window in the dot matrix can not only be individually controlled by the connected optical fiber, but also be modulated in a programmable manner, thereby meeting the needs of light emission or detection of some special patterns; 5) The optical fiber array distribution prepared by the present invention can be designed into different patterns according to the needs of light emission or detection; 6) The optical fiber array chip prepared by the present invention can also be used in scenarios where simultaneous light emission and optical detection are required.

[0028] The features and advantages of the present invention will be described in detail through embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a flow chart of steps a) to d) of embodiment 1; Figure 2 is a flow chart of step e) to step h) of embodiment 1; Figure 3 is a flow chart of steps a) to c) of embodiment 2; Figure 4 is a flow chart from step d) to step a) of embodiment 2; Figure 5 is a schematic structural diagram of the optical fiber array chip of the second embodiment; Figure 6 It is a schematic diagram of the structure of the optical fiber array chip of the third embodiment.

[0030] In the figure: 1-substrate, 11-inner concave portion, 2-light-transmitting film, 21-light-transmitting needle, 3-first optical adhesive layer, 31-first optical adhesive hole, 4-limiting film, 41-limiting hole, 5-second optical adhesive layer, 51-second optical adhesive hole, 6-optical fiber, 7-upper packaging sheet, 71-upper packaging hole, 8-optical reflective film, 81-lower convex portion. DETAILED DESCRIPTION

[0031] Embodiment 1: See also Figure 1 and Figure 2 The method for preparing the optical fiber array chip of this embodiment comprises the following steps: a) One-time etching: etching a plurality of inner recesses 11 on the top surface of a substrate 1 (using a metal substrate with a diameter of 6 to 12 inches, such as an aluminum substrate, stainless steel substrate, titanium substrate or tungsten substrate with a diameter of 8 inches) by using a photoresist etching technique or a maskless laser etching technique; For the photoresist etching technology, firstly, photoresist is coated on the top surface of the substrate 1 to form a first photoresist layer 3; after drying the first photoresist layer 3, a mask is used to block the light so that light can irradiate a part of the first photoresist layer 3, and then a developer is used to dissolve the exposed or unexposed area of ​​the first photoresist layer 3 and form a first photoresist hole 31; then, the plasma generated under the action of the electric field is used to pass through the first photoresist hole 31 and bombard and erode the substrate 1 (i.e., plasma chemical (RIE) etching) until an inverted cone-shaped inner concave portion 11 is generated (due to the presence of photoresist material in the etching chamber, part of the photoresist material will cover the etched interface under ion bombardment and protect the interface from further etching, thereby obtaining an inverted cone-shaped cavity, and by adjusting the parameters in the plasma etching chamber, cavities of different tapers can be etched), and finally, the remaining first photoresist layer 3 is removed and cleaned; The photoresist etching technology can also be replaced by a maskless laser etching technology (i.e., using a high-energy-density laser to irradiate the top surface of the substrate 1, so that the surface material of the irradiated area undergoes a series of complex physical and even chemical processes such as heating, melting, vaporization, plasma formation, volatilization and sputtering to form the inner concave portion 11; b) One-time film formation: depositing silica glass on the top surface of the substrate 1 by chemical vapor deposition technology (specifically, PCECVD or LPCVD technology can be selected) and then subjecting the substrate 1 to high-temperature annealing to generate a light-transmitting film 2 (i.e., a silica glass film), wherein the light-transmitting film 2 is simultaneously subjected to a vapor phase doping treatment during the chemical vapor deposition treatment; c) Film removal: mechanical polishing or chemical mechanical polishing is used to remove the light-transmitting film 2 except for the light-transmitting needles 21; d) Secondary film formation: generating a limiting film 4 on the top surface of the substrate 1 by chemical vapor deposition technology and making the limiting film 4 cover each light-transmitting needle 21 at the same time; wherein the limiting film 4 is a metal film (such as an aluminum film, a titanium film or a tungsten film) or a silicon-based inorganic non-metallic film (such as a silicon film or a silicon nitride film) and has a thickness of 0.1 to 50 μm; e) Secondary etching: etching on the top surface of the limiting film 4 (using photoresist etching technology or maskless laser etching technology, the same as step a); if the photoresist etching technology is used, the first photoresist layer 3 and the first photoresist hole 31 are replaced with the second photoresist layer 5 and the second photoresist hole 51) to form limiting holes 41 respectively connected to each light-transmitting needle 21; f) bottom film removal: using mechanical polishing or chemical mechanical polishing technology to remove part of the substrate 1 from bottom to top until the bottom ends of the light-transmitting needles 21 are exposed; g) Connecting optical fibers: Connecting optical fibers 6 (with a diameter of 1 to 100 μm and made of silica glass) to the top of each light-transmitting needle 21; h) Packaging: The top surface of the limiting film 4 and the bottom surface of the substrate 1 are packaged at the same time. The top surface of the limiting film 4 is packaged through an upper packaging sheet 7 with a plurality of upper packaging holes 71, and each optical fiber 6 is respectively extended into the corresponding upper packaging hole 71. The bottom surface of the substrate 1 is packaged through a lower packaging sheet that simultaneously covers each light-transmitting needle 21; wherein the upper packaging sheet 7 is made of an organic polymer packaging material or an inorganic ceramic packaging material, and the lower packaging sheet is a transparent film.

[0032] Embodiment 2: See also Figure 3 and Figure 4 The method for preparing the optical fiber array chip of this embodiment has the same steps as those of the first embodiment except for the following steps: a) One-time etching: using photoresist etching technology or maskless laser etching technology to etch a plurality of inner recesses 11 on the top surface of a substrate 1 (using a silicon-based inorganic non-metallic substrate with a diameter of 6 to 12 inches, such as a single crystal silicon wafer, a polycrystalline silicon wafer or a silicon carbide wafer with a diameter of 8 inches); b) One-time film formation: firstly, an optical reflective film 8 is formed on the top surface of the substrate 1 by chemical vapor deposition technology, and the optical reflective film 8 is deposited on the surface of each inner concave portion 11 to form a corresponding lower convex portion 81, and then a light-transmitting film 2 is formed on the top surface of the optical reflective film 8 by chemical vapor deposition technology, and the light-transmitting film 2 fills each lower convex portion 81 to form a corresponding light-transmitting needle 21; wherein the optical reflective film 8 is a metal film (such as a tungsten film) and has a thickness of 0.1 to 10 μm; d) Secondary film formation: generating a limiting film 4 on the top surface of the optical reflective film 8 and making the limiting film 4 cover all the light-transmitting needles 21 at the same time.

[0033] Finally, the optical fiber array chip prepared in this embodiment has the light-transmitting needles 21 arranged in a parallel linear array (see Figure 5 ).

[0034] Embodiment three: The optical fiber array chip prepared in this embodiment has the light-transmitting needles 21 arranged in a staggered linear array (see Figure 6 ), the rest is the same as in Example 2.

[0035] The above embodiments are intended to illustrate the present invention, not to limit the present invention. Any solution that is a simple transformation of the present invention belongs to the protection scope of the present invention.

Claims

1. An optical fiber array chip, characterized in that: It has a plurality of light-transmitting needles (21) arranged in a parallel linear array or a staggered linear array.

2. The method for preparing the optical fiber array chip according to claim 1, characterized in that: The steps include: a) primary etching: etching a plurality of inner recesses (11) on the top surface of the substrate (1); b) One-time film formation: adopt scheme 1 or scheme 2; The first solution is to form a light-transmitting film (2) on the top surface of the substrate (1) and to allow the light-transmitting film (2) to fill each inner concave portion (11) to form a corresponding light-transmitting needle (21); The second scheme is to first generate an optical reflective film (8) on the top surface of the substrate (1) and deposit the optical reflective film (8) on the surface of each inner concave portion (11) to form a corresponding lower convex portion (81), and then generate a light-transmitting film (2) on the top surface of the optical reflective film (8) and fill each lower convex portion (81) with the light-transmitting film (2) to form a corresponding light-transmitting needle (21); c) film removal: removing the light-transmitting film (2) except for the light-transmitting needles (21); d) Secondary film formation: forming a limiting film (4) on the top surface of the substrate (1) or the optical reflective film (8) and making the limiting film (4) cover each light-transmitting needle (21) at the same time; e) secondary etching: etching limiting holes (41) on the top surface of the limiting film (4) and each of which is connected to each light-transmitting needle (21); f) bottom film removal: removing part of the substrate (1) from bottom to top until the bottom ends of the light-transmitting needles (21) are exposed; Connecting optical fibers: Connecting optical fibers (6) to the tops of the light-transmitting needles (21); h) Packaging: Only the top surface of the limiting film (4) is packaged or both the top surface of the limiting film (4) and the bottom surface of the substrate (1) are packaged. The packaging is achieved on the top surface of the limiting film (4) through an upper packaging sheet (7) with a plurality of upper packaging holes (71) and each optical fiber (6) is extended into the corresponding upper packaging hole (71). The packaging is achieved on the bottom surface of the substrate (1) through a lower packaging sheet that simultaneously covers each light-transmitting needle (21).

3. The method for preparing the optical fiber array chip according to claim 2, characterized in that: The substrate (1) is a metal substrate when the first solution is adopted and is a silicon-based inorganic non-metal substrate when the second solution is adopted.

4. The method for preparing the optical fiber array chip according to claim 2, characterized in that: The light-transmitting film (2) is a silica glass film, and the optical fiber (6) is made of silica glass.

5. The method for preparing the optical fiber array chip according to claim 2, characterized in that: The limiting film (4) is a metal film or a silicon-based inorganic non-metallic film.

6. The method for preparing the optical fiber array chip according to claim 2, characterized in that: The optical reflective film (8) is a metal film.

7. The method for preparing the optical fiber array chip according to claim 2, characterized in that: The thickness of the limiting film (4) is 0.1 to 50 μm, the diameter of each optical fiber (6) is 1 to 100 μm, and the thickness of the optical reflective film (8) is 0.1 to 10 μm.

8. The method for preparing the optical fiber array chip according to claim 2, characterized in that: The upper packaging sheet (7) is made of an organic polymer packaging material or an inorganic ceramic packaging material, and the lower packaging sheet is a transparent film.

9. The method for preparing the optical fiber array chip according to claim 2, characterized in that: The light-transmitting film (2), the limiting film (4) and the optical reflective film (8) are all formed by deposition using chemical vapor deposition technology, the steps a) and e) both use photoresist etching technology or maskless laser etching technology to complete the etching operation, and the steps c) and f) use mechanical polishing or chemical mechanical polishing technology to complete the film removal operation.

10. The method for preparing the optical fiber array chip according to claim 9, characterized in that: The light-transmitting film (2) is subjected to a vapor phase doping treatment simultaneously during the chemical vapor deposition treatment, and the light-transmitting film (2) is further subjected to a high-temperature annealing treatment after the chemical vapor deposition treatment is completed.

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