阅读说明：本技术 一种snspd阵列与光波导阵列的耦合装置及方法 (Coupling device and method for SNSPD array and optical waveguide array ) 是由 张伟君 徐光照 李�浩 尤立星 谢晓明 于 2020-03-18 设计创作，主要内容包括：本申请提供一种SNSPD阵列与光波导阵列的耦合装置及方法,该耦合装置包括金属底座、硅衬底层、DBR介质层和上表面刻蚀有SNSPD阵列的氮化铌层,光波导阵列和固定座,其中,单元光波导与单元SNSPD一一对应,固定座的一端与光波导阵列的侧表面连接另一端与金属底座的上表面连接。本申请相较于传统的单个SNSPD器件与单根光纤耦合的方法,本申请具有提高SNSPD集成度、拓展器件规模等优点,并且还有助于提高工作效率和实现SNSPD大批量生产,此外,相较于片上集成斜入射耦合或射倏逝波耦合方法,采用分离式垂直耦合的方法将SNSPD阵列与光波导阵列直接耦合,能够有效减少光路损耗,提高光耦合效率。(The coupling device comprises a metal base, a silicon substrate layer, a DBR medium layer, a niobium nitride layer with an upper surface etched with an SNSPD array, an optical waveguide array and a fixing seat, wherein unit optical waveguides correspond to the unit SNSPDs one to one, one end of the fixing seat is connected with the side surface of the optical waveguide array, and the other end of the fixing seat is connected with the upper surface of the metal base. Compared with the traditional method for coupling a single SNSPD device and a single optical fiber, the method has the advantages of improving the integration degree of the SNSPD, expanding the scale of the device and the like, is favorable for improving the working efficiency and realizing the mass production of the SNSPD, and in addition, compared with the on-chip integrated oblique incidence coupling or evanescent wave coupling method, the method for directly coupling the SNSPD array and the optical waveguide array by adopting a separated vertical coupling method can effectively reduce the optical path loss and improve the optical coupling efficiency.)

1. A coupling device of an SNSPD array and an optical waveguide array is characterized by comprising:

a first component; the first assembly sequentially comprises a metal base and an SNSPD array chip from bottom to top; the SNSPD array chip sequentially comprises a silicon substrate layer, a DBR dielectric layer and a niobium nitride layer from bottom to top, wherein an SNSPD array is etched on the upper surface of the niobium nitride layer;

a second component; the second component comprises an optical waveguide array; unit optical waveguides in the optical waveguide array correspond to the SNSPDs in the SNSPD array one by one;

a fixing assembly; the fixing component comprises a fixing seat; one end of the fixed seat is connected with the side surface of the optical waveguide array, and the other end of the fixed seat is connected with the upper surface of the metal base.

2. The apparatus of claim 1, wherein the optical waveguide array comprises any one of:

an optical fiber array; alternatively, the first and second electrodes may be,

the optical fiber array and the femtosecond laser direct writing waveguide; the optical fiber array comprises a single-mode optical fiber array or a multi-mode optical fiber array;

the second assembly further comprises a connecting slot;

the optical fiber array is connected with the connecting groove; alternatively, the first and second electrodes may be,

the optical fiber array, the connecting groove and the femtosecond laser direct writing waveguide are sequentially connected;

the connecting groove is used for determining the position of a light beam channel formed after the optical fiber array is coupled with the femtosecond laser direct writing waveguide.

3. The apparatus of claim 1, wherein the fixation assembly further comprises an ultraviolet or low temperature glue;

the ultraviolet curing glue or the low-temperature glue is used for fixing the optical waveguide array and the SNSPD array.

4. The apparatus of claim 1, wherein a photosensitive area corresponding to a SNSPD of a cell in the SNSPD array is larger than a mode field diameter corresponding to a cell optical waveguide in the optical waveguide array.

5. The apparatus of claim 1, wherein the SNSPD array comprises, but is not limited to, a one-dimensional linear array or a two-dimensional planar array.

6. A coupling method of an SNSPD array and an optical waveguide array is characterized by comprising the following steps:

obtaining a silicon substrate layer;

preparing a DBR dielectric layer on the silicon substrate layer;

preparing a niobium nitride layer on the upper surface of the DBR dielectric layer, and etching an SNSPD array on the upper surface of the niobium nitride layer;

vertically aligning an optical waveguide array to the SNSPD array by using an alignment auxiliary device for coupling, so that unit optical waveguides in the optical waveguide array correspond to unit SNSPDs in the SNSPD array one by one;

and fixing the optical waveguide array on the metal base by using a fixing component.

7. The method of claim 6, wherein the optical waveguide array comprises an array of single mode optical fibers;

and single optical fibers in the single mode optical fiber array correspond to the SNSPDs in the SNSPD array one by one.

8. The method of claim 6, wherein the optical waveguide array comprises a single mode fiber array and a femtosecond laser direct write waveguide;

and single optical fibers in the single mode optical fiber array correspond to unit waveguides in the femtosecond laser direct writing waveguide one by one, and the unit waveguides in the femtosecond laser direct writing waveguide correspond to the unit SNSPDs in the SNSPD array one by one.

9. The method of claim 6, wherein the optical waveguide array comprises a multimode optical fiber array and a femtosecond laser direct writing waveguide;

and single optical fibers in the multimode optical fiber array correspond to unit waveguides in the femtosecond laser direct writing waveguide one by one, and the unit waveguides in the femtosecond laser direct writing waveguide correspond to the unit SNSPDs in the SNSPD array one by one.

10. The method of claim 6, wherein coupling the optical waveguide array to the SNSPD array vertically with an alignment aid comprises:

and vertically aligning the optical waveguide array to the SNSPD array for coupling by using a high-precision four-dimensional mobile platform.

Technical Field

The invention relates to the technical field of device integration, in particular to a coupling device and a coupling method of an SNSPD array and an optical waveguide array.

Background

The super conductor nanowire single photon detector (SNSPD) is a novel single photon detector, compared with a conventional semiconductor detector, the SNSPD has the advantages of ultrahigh detection efficiency, extremely low dark count, less time jitter, higher counting rate and the like, and not only can realize wider spectral response, but also can extend the detection range from visible light to an infrared band. Over ten years of development, the technical research and development of SNSPD is mature day by day, the detection efficiency in a detection system with 1550nm waveband can reach 90%, the counting rate exceeds 1GHz, and the time jitter is less than 10 ps.

Due to the characteristics of high coupling precision requirement (deviation <5 μm) and low-temperature operation (< 4K), the optical coupling of the conventional SNSPD generally adopts a coupling mode of a single device and a single optical fiber. For example, the self-aligned packaging of the optical fiber and the device is achieved by using a ceramic sleeve, or the optical fiber is glued on a metal component and then fixed on a chip base by using a screw. At present, accurate coupling of a single SNSPD is already possible, and accurate coupling of multiple SNSPD devices on the same chip to multiple fibers remains a challenge. Therefore, a method of on-chip self-alignment has been proposed, in which a deep hole is etched in a substrate with hydrofluoric acid below each photosensitive surface of a chip, and an optical fiber is inserted into the hole to align the optical fiber with the photosensitive surface of the device, but due to the limitations of the etching inclination angle, the etching surface roughness, and the remaining thin silicon wall (> 20 μm), it is difficult to further improve the detection effect of the device.

Optical Waveguide devices (OW) are important components of optoelectronic integrated devices or systems, and are dielectric devices for guiding light to propagate therein, and have good Optical, electrical, mechanical properties and thermal stability. The optical fiber array, the femtosecond laser direct writing waveguide, the planar process waveguide and the like are optical waveguide devices which are popular and applied at present, particularly the optical fiber array, a plurality of optical fibers are bonded in a V-shaped groove of silicon, and the accurate positioning of unit optical fibers can be realized due to the high processing precision of the V-shaped groove, for example, the horizontal distance of the core diameter of the unit optical fibers is 127 micrometers, the deviation is less than 1 micrometer, the vertical deviation of the center of the unit is less than 0.2 micrometer, if the femtosecond laser direct writing waveguide is adopted, the refractive index of a local area in a substrate material is induced to change by scanning the substrate material by adopting a focused femtosecond laser pulse, a formed waveguide structure is formed, and the deviation of the core diameter coordinate of the waveguide can be less than submicron.

At present, optical detection experiments on different optical waveguide structures have become an important research direction in the field of single photon detection, wherein integration, large scale and operability of optical paths are a great problem for researchers, especially in performing matching alignment of multiple optical paths with multiple SNSPDs of multiple units.

Disclosure of Invention

The embodiment of the application provides a coupling device and a coupling method of an SNSPD array and an optical waveguide array, which can realize large-scale integration of devices and have the advantages of simplicity in operation and high coupling precision.

The embodiment of the application discloses a coupling device of an SNSPD array and an optical waveguide array, the device comprises:

a first component; the first assembly sequentially comprises a metal base and an SNSPD array chip from bottom to top; the SNSPD array chip sequentially comprises a silicon substrate layer, a DBR dielectric layer and a niobium nitride layer from bottom to top, wherein an SNSPD array is etched on the upper surface of the niobium nitride layer;

a second component; the second assembly includes an array of optical waveguides; unit optical waveguides in the optical waveguide array correspond to the SNSPDs in the SNSPD array one by one;

a fixing assembly; the fixing component comprises a fixing seat; one end of the fixed seat is connected with the side surface of the optical waveguide array, and the other end of the fixed seat is connected with the upper surface of the metal base.

Further, the optical waveguide array includes any one of:

an optical fiber array; alternatively, the first and second electrodes may be,

the optical fiber array and the femtosecond laser direct writing waveguide; the optical fiber array comprises a single-mode optical fiber array or a multi-mode optical fiber array;

the second assembly further comprises a connecting groove;

the optical fiber array is connected with the connecting groove; alternatively, the first and second electrodes may be,

the optical fiber array, the connecting groove and the femtosecond laser direct writing waveguide are sequentially connected;

the connecting groove is used for determining the position of a light beam channel formed after the optical fiber array is coupled with the femtosecond laser direct writing waveguide.

Furthermore, the fixing component also comprises ultraviolet curing glue or low-temperature glue; and the ultraviolet curing glue or the low-temperature glue is used for fixing the optical waveguide array and the SNSPD array.

Further, the photosensitive area corresponding to the SNSPD of the unit SNSPD in the SNSPD array is larger than the mode field diameter corresponding to the unit optical waveguide in the optical waveguide array.

Further, the SNSPD array includes, but is not limited to, a one-dimensional linear array or a two-dimensional planar array.

Correspondingly, the embodiment of the application also provides a coupling method of the SNSPD array and the optical waveguide array, and the method comprises the following steps:

obtaining a silicon substrate layer;

preparing a DBR medium layer on the silicon substrate layer;

preparing a niobium nitride layer on the upper surface of the DBR medium layer, and etching an SNSPD array on the upper surface of the niobium nitride layer;

vertically aligning the optical waveguide array with the SNSPD array by using an alignment auxiliary device for coupling, so that unit optical waveguides in the optical waveguide array correspond to units SNSPDs in the SNSPD array one by one;

and fixing the optical waveguide array on the metal base by using the fixing component.

Further, the optical waveguide array comprises a single mode fiber array;

and single optical fibers in the single mode optical fiber array correspond to the SNSPDs in the SNSPD array one by one.

Further, the optical waveguide array comprises a single-mode optical fiber array and a femtosecond laser direct writing waveguide;

the single optical fiber in the single mode optical fiber array corresponds to the unit waveguide in the femtosecond laser direct writing waveguide one by one, and the unit waveguide in the femtosecond laser direct writing waveguide corresponds to the unit SNSPD in the SNSPD array one by one.

Further, the optical waveguide array comprises a multimode optical fiber array and a femtosecond laser direct writing waveguide;

the single optical fiber in the multimode optical fiber array corresponds to the unit waveguide in the femtosecond laser direct writing waveguide one by one, and the unit waveguide in the femtosecond laser direct writing waveguide corresponds to the unit SNSPD in the SNSPD array one by one.

Further, vertically aligning the optical waveguide array with the SNSPD array for coupling by using an alignment aid, comprising:

and vertically aligning the optical waveguide array with the SNSPD array for coupling by using a high-precision four-dimensional mobile platform.

By adopting the technical scheme, the application has the following beneficial effects:

the embodiment of the application provides a coupling device and a method of an SNSPD array and an optical waveguide array, wherein the coupling device comprises a first assembly, wherein the first assembly sequentially comprises a metal base and an SNSPD array chip from bottom to top, the SNSPD array chip sequentially comprises a silicon substrate layer, a DBR dielectric layer and a niobium nitride layer from bottom to top, the upper surface of the niobium nitride layer is etched with the SNSPD array, and a second assembly, wherein the second assembly comprises the optical waveguide array, unit optical waveguides in the optical waveguide array correspond to unit SNSPDs in the SNSPD array one by one, and the fixing assembly comprises a fixing base, one end of the fixing base is connected with the side surface of the optical waveguide array, and the other end of the fixing base is connected with the upper surface of the metal base. Based on the embodiment of the application, compared with a traditional method for coupling a single SNSPD device and a single optical fiber, the method has the advantages of improving the integration degree of the SNSPD, expanding the scale of the device and the like, is also beneficial to improving the working efficiency and realizing the mass production of the SNSPD, and in addition, compared with an on-chip integrated oblique incidence coupling or evanescent wave coupling method, the method for coupling the SNSPD array and the optical waveguide array directly adopts a separated vertical coupling method, so that the optical path loss can be effectively reduced, and the optical coupling efficiency is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic plan structure diagram of a coupling device of an SNSPD array and an optical waveguide array according to an embodiment of the present disclosure;

FIG. 2 is a schematic perspective view of the coupling device of the SNSPD array and the optical waveguide array provided in FIG. 1;

FIG. 3 is an enlarged view of the coupling position in the three-dimensional structure of the coupling device of the SNSPD array and the optical waveguide array provided in FIG. 2;

fig. 4 is a schematic plan structure diagram of a coupling device of an SNSPD array and an optical waveguide array according to an embodiment of the present disclosure;

FIG. 5 is a schematic perspective view of the coupling device of the SNSPD array and the optical waveguide array provided in FIG. 4;

FIG. 6 is an enlarged view of the coupling position in the three-dimensional structure of the coupling device of the SNSPD array and the optical waveguide array provided in FIG. 5;

fig. 7 is a schematic plan structure diagram of a coupling device of an SNSPD array and an optical waveguide array according to an embodiment of the present disclosure;

FIG. 8 is a schematic perspective view of the coupling device of the SNSPD array and the optical waveguide array provided in FIG. 7;

FIG. 9 is an enlarged view of the coupling position in the three-dimensional structure of the coupling device of the SNSPD array and the optical waveguide array provided in FIG. 8;

fig. 10 is a schematic cross-sectional structure diagram of an SNSPD array chip and a metal base according to an embodiment of the present disclosure;

fig. 11 is a schematic diagram of a three-dimensional device for connecting the SNSPD array to an external circuit according to an embodiment of the present disclosure;

fig. 12 is a schematic flowchart of a coupling method of an SNSPD array and an optical waveguide array according to an embodiment of the present disclosure.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

An "embodiment" as referred to herein relates to a particular feature, structure, or characteristic that may be included in at least one implementation of the present application. It should be understood that in the description of the embodiments of the present application, the terms "upper" and "lower" etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present application. It should be noted that the term "comprises/comprising" and any variations thereof, is intended to cover non-exclusive inclusions, e.g. an apparatus or method comprising a list of structures or steps, is not necessarily limited to those structures or steps, but may include other structures or steps not expressly listed or inherent to such apparatus or method.

Referring to fig. 1, fig. 1 is a schematic plan structure view of a coupling device of an SNSPD array and an optical waveguide array according to an embodiment of the present application, where the coupling device includes: the optical waveguide device comprises a first component 1, a second component 2 and a third component 3, wherein the first component sequentially comprises a metal base 11 and an SNSPD array chip from bottom to top, the SNSPD array chip sequentially comprises a silicon substrate layer 12, a DBR dielectric layer 13 and a niobium nitride layer from bottom to top, an SNSPD array 14 is etched on the upper surface of the niobium nitride layer, the second component 2 comprises an optical waveguide array 21, unit optical waveguides in the optical waveguide array 21 correspond to unit SNSPDs in the SNSPD array 14 one by one, the fixing component 3 comprises a fixing seat 31, one end of the fixing seat 31 is connected with the side surface of the optical waveguide array 21, and the other end of the fixing seat 31 is connected with the upper surface of the metal base 11.

Based on the coupling device of the SNSPD array and the optical waveguide array described in fig. 1, specific structural schematic diagrams of several coupling devices of the SNSPD array and the optical waveguide array are introduced.

In an alternative implementation manner, as shown in fig. 1, fig. 2 and fig. 3, fig. 1 is a schematic plan structure diagram of a coupling device of an SNSPD array and an optical waveguide array according to an embodiment of the present application, fig. 2 is a schematic perspective structure diagram of the coupling device of the SNSPD array and the optical waveguide array provided in fig. 1, and fig. 3 is an enlarged view of a coupling position in a perspective structure of the coupling device of the SNSPD array and the optical waveguide array provided in fig. 2.

The coupling device of the NSPD array and the optical waveguide array comprises a first component 1, a second component 2 and a third component 3, wherein the first component sequentially comprises a metal base 11 and an SNSPD array chip from bottom to top, the SNSPD array chip sequentially comprises a silicon substrate layer 12, a DBR dielectric layer 13 and a niobium nitride layer from bottom to top, and an SNSPD array 14 is etched on the upper surface of the niobium nitride layer; the second component 2 comprises an optical waveguide array 21 and a connecting groove 22, wherein unit optical waveguides in the optical waveguide array 21 correspond to the SNSPDs in the SNSPD array 14 one by one, and the photosensitive area corresponding to the SNSPDs in the SNSPD array 14 is larger than the mode field diameter corresponding to the unit optical waveguides in the optical waveguide array 21; the fixing component 3 comprises a fixing seat 31 and ultraviolet curing glue or low-temperature glue, the ultraviolet curing glue or the low-temperature glue is used for fixing the optical waveguide array 21 and the SNSPD array 14, one end of the fixing seat 31 is connected with the side surface of the optical waveguide array 21, and the other end of the fixing seat 31 is connected with the upper surface of the metal base 11. Wherein, the connecting groove 22 may be a V-groove, i.e. a V-shaped connecting groove, and the fixing seat 31 may be a triangular clamping part.

Specifically, the optical waveguide array 21 mentioned above includes a single-mode optical fiber array 211 and a femtosecond laser direct-writing waveguide 212, where the single-mode optical fiber array 211 is a one-dimensional linear array, the single-mode optical fiber array 211, the connection groove 22, and the femtosecond laser direct-writing waveguide 212 are connected in sequence, and the single-mode optical fiber array 211, the connection groove 22, and the femtosecond laser direct-writing waveguide 212 connected in sequence are connected to the SNSPD array 14 by using a high-precision X, Y, Z and a high-precision θ four-dimensional mobile platform, so that a single optical fiber in the single-mode optical fiber array 211 corresponds to a unit waveguide in the femtosecond laser direct-writing waveguide 212 one to one, and a unit waveguide in the femtosecond laser direct-writing waveguide 212 corresponds to a unit SNSPD in the.

In another alternative implementation, as shown in fig. 4, 5 and 6, fig. 4 is a schematic plan structure diagram of a coupling device of an SNSPD array and an optical waveguide array according to an embodiment of the present disclosure, fig. 5 is a schematic perspective structure diagram of the coupling device of the SNSPD array and the optical waveguide array provided in fig. 4, and fig. 6 is an enlarged view of a coupling position in a perspective structure of the coupling device of the SNSPD array and the optical waveguide array provided in fig. 4.

The coupling device of the NSPD array and the optical waveguide array comprises a first component 1, a second component 2 and a third component 3, wherein the first component sequentially comprises a metal base 11 and an SNSPD array chip from bottom to top, the SNSPD array chip sequentially comprises a silicon substrate layer 12, a DBR dielectric layer 13 and a niobium nitride layer from bottom to top, and an SNSPD array 14 is etched on the upper surface of the niobium nitride layer; the second component 2 comprises an optical waveguide array 21 and a connecting groove 22, wherein unit optical waveguides in the optical waveguide array 21 correspond to the SNSPDs in the SNSPD array 14 one by one, and the photosensitive area corresponding to the SNSPDs in the SNSPD array 14 is larger than the mode field diameter corresponding to the unit optical waveguides in the optical waveguide array 21; the fixing component 3 comprises a fixing seat 31 and ultraviolet curing glue or low-temperature glue, the ultraviolet curing glue or the low-temperature glue is used for fixing the optical waveguide array 21 and the SNSPD array 14, one end of the fixing seat 31 is connected with the side surface of the optical waveguide array 21, and the other end of the fixing seat 31 is connected with the upper surface of the metal base 11. Wherein, the connecting groove 22 may be a V-groove, i.e. a V-shaped connecting groove, and the fixing seat 31 may be a triangular clamping part.

Specifically, the optical waveguide array 21 mentioned above includes a multimode optical fiber array 213 and a femtosecond laser direct writing waveguide 212, where the multimode optical fiber array 213 is a two-dimensional area array, the multimode optical fiber array 213, the connection slot 22, and the femtosecond laser direct writing waveguide 212 are sequentially connected, and the multimode optical fiber array 213, the connection slot 22, and the femtosecond laser direct writing waveguide 212, which are sequentially connected, are connected with the SNSPD array 14 by using a high-precision X, Y, Z, θ four-dimensional moving platform, so that a single optical fiber in the multimode optical fiber array 213 corresponds to a unit waveguide in the femtosecond laser direct writing waveguide 212 one by one, and a unit waveguide in the femtosecond laser direct writing waveguide 212 corresponds to a unit SNSPD in the SNSPD array 14 one by one.

In another alternative implementation, as shown in fig. 7, 8 and 9, fig. 7 is a schematic plan structure diagram of a coupling device of an SNSPD array and an optical waveguide array according to an embodiment of the present disclosure, fig. 8 is a schematic perspective structure diagram of the coupling device of the SNSPD array and the optical waveguide array provided in fig. 7, and fig. 9 is an enlarged view of a coupling position in a perspective structure of the coupling device of the SNSPD array and the optical waveguide array provided in fig. 8.

The coupling device of the NSPD array and the optical waveguide array comprises a first component 1, a second component 2 and a third component 3, wherein the first component sequentially comprises a metal base 11 and an SNSPD array chip from bottom to top, the SNSPD array chip sequentially comprises a silicon substrate layer 12, a DBR dielectric layer 13 and a niobium nitride layer from bottom to top, and an SNSPD array 14 is etched on the upper surface of the niobium nitride layer; the second component 2 comprises an optical waveguide array 21 and a connecting groove 22, wherein unit optical waveguides in the optical waveguide array 21 correspond to the SNSPDs in the SNSPD array 14 one by one, and the photosensitive area corresponding to the SNSPDs in the SNSPD array 14 is larger than the mode field diameter corresponding to the unit optical waveguides in the optical waveguide array 21; the fixing component 3 comprises a fixing seat 31 and ultraviolet curing glue or low-temperature glue, the ultraviolet curing glue or the low-temperature glue is used for fixing the optical waveguide array 21 and the SNSPD array 14, one end of the fixing seat 31 is connected with the side surface of the optical waveguide array 21, and the other end of the fixing seat 31 is connected with the upper surface of the metal base 11. Wherein, the connecting groove 22 may be a V-groove, i.e. a V-shaped connecting groove, and the fixing seat 31 may be a triangular clamping part.

Specifically, the optical waveguide array 21 mentioned above includes a single-mode optical fiber array 211, where the single-mode optical fiber array 211 is a one-dimensional linear array, the single-mode optical fiber array 211 is connected with the connection slot 22, and the connected single-mode optical fiber array 211 and connection slot 22 are connected with the SNSPD array 14 by using a high-precision X, Y, Z, θ four-dimensional moving platform, so that a single optical fiber in the single-mode optical fiber array 211 corresponds to a unit SNSPD in the SNSPD array 14 one-to-one.

The coupling device of the SNSPD array and the optical waveguide array comprises a metal base, an SNSPD array chip, the optical waveguide array and a fixing base, wherein unit optical waveguides in the optical waveguide array correspond to units SNSPDs in the SNSPD array one by one, one end of the fixing base is connected with the side surface of the optical waveguide array, and the other end of the fixing base is connected with the upper surface of the metal base. Based on the embodiment of the application, compared with a traditional method for coupling a single SNSPD device and a single optical fiber, the method has the advantages of improving the integration degree of the SNSPD, expanding the scale of the device and the like, is also beneficial to improving the working efficiency and realizing the mass production of the SNSPD, and in addition, compared with an on-chip integrated oblique incidence coupling or evanescent wave coupling method, the method for coupling the SNSPD array and the optical waveguide array directly adopts a separated vertical coupling method, so that the optical path loss can be effectively reduced, and the optical coupling efficiency is improved.

Referring to fig. 10, fig. 10 is a schematic cross-sectional structure view of an SNSPD array chip and a metal base according to an embodiment of the present application, namely, the first component described above, which includes, from bottom to top: the semiconductor device comprises a metal base 11, a silicon substrate layer 12, a DBR dielectric layer 13 and a niobium nitride layer with an SNSPD array 14 etched on the upper surface.

In particular, the metal base 11 described above may be a metal enclosure for holding the SNSPD array 14. The silicon substrate layer 12 described above may be embodied as a commercial silicon wafer substrate, the DBR dielectric layer 13 is used to enhance the optical absorption efficiency of the device, and typically the DBR dielectric layer 13 is formed of silicon dioxide SiO₂And niobium dioxide TiO₂The double-layer medium is alternatively deposited, the above-mentioned niobium nitride layer can be prepared by utilizing magnetron sputtering technique, and the SNSPD array 14 on the described niobium nitride layer can utilize electron beam exposure and development technique to etch SNSP on the upper surface of the niobium nitride layerThe D array 14 may also be an SNSPD array 14 etched on the upper surface of the niobium nitride layer by using techniques such as ultraviolet lithography or reactive ion etching.

Referring to fig. 11, fig. 11 is a schematic diagram of a three-dimensional device of an SNSPD array and an external circuit according to an embodiment of the present application, where the three-dimensional device includes: the circuit assembly comprises a first assembly 1, a second assembly 2 and a circuit assembly, wherein the first assembly sequentially comprises a metal base 11, a silicon substrate layer 12, a DBR dielectric layer 13 and a niobium nitride layer from bottom to top, an SNSPD array 14 is etched on the upper surface of the niobium nitride layer, the second assembly 2 comprises an optical waveguide array 21 and connecting grooves 22, unit optical waveguides in the optical waveguide array 21 correspond to unit SNSPDs in the SNSPD array 14 in a one-to-one mode, the circuit assembly 4 comprises a PCB 41, an electric connector 43 (such as an SMP connector) used for transmitting electric signals and an electric conductor 42 used for connecting the SNSPD array 14, the PCB 41 and the electric connector 43, one end of the PCB 41 is connected with the SNSPD array 14 through an aluminum wire, and the other end of the PCB 41 is connected with the SMP connector through an aluminum wire.

Referring to fig. 12, fig. 12 is a schematic flowchart of a coupling method of an SNSPD array and an optical waveguide array according to an embodiment of the present application, where the method includes:

s1201: and obtaining the silicon substrate layer.

S1203: and preparing a DBR medium layer on the silicon substrate layer.

S1205: preparing a niobium nitride layer on the upper surface of the DBR dielectric layer, and etching the SNSPD array on the upper surface of the niobium nitride layer.

S1207: and vertically aligning the optical waveguide array to the SNSPD array by using an alignment auxiliary device for coupling, so that unit optical waveguides in the optical waveguide array correspond to the unit SNSPDs in the SNSPD array one by one.

In the embodiment of the present application, the optical waveguide array 21 includes an optical fiber array, or an optical fiber array and the femtosecond laser direct writing waveguide 212, wherein the optical fiber array includes a single mode optical fiber array 211 and a multimode optical fiber array 213. Before the optical waveguide array 21 is vertically aligned with the SNSPD array 14 for coupling by using the alignment auxiliary device, the method further comprises the steps of coupling the optical fiber array 21 with the femtosecond laser direct-writing waveguide 212, enabling the single optical fiber in the optical fiber array 21 to correspond to the unit waveguides in the femtosecond laser direct-writing waveguide 212 one by one, and fixedly connecting the optical fiber array with the femtosecond laser direct-writing waveguide by using ultraviolet curing glue or low-temperature glue.

In the embodiment of the present application, the alignment device described above may be an optical microscope, and may also be an X, Y, Z, θ four-bit moving platform, and the optical microscope or the X, Y, Z, θ four-bit moving platform is used to precisely align the unit waveguides in the femtosecond laser direct-write waveguide with the SNSPDs of the cells in the SNSPD array. It should be noted that the distance between adjacent unit waveguides in the femtosecond laser direct writing waveguide and the distance between adjacent unit SNSPDs in the SNSPD array are within a preset deviation value range, and the preset deviation value is ± 5 micrometers. The emergent light beam channels of the waveguides in the waveguide array are in one-to-one correspondence with the positions of the photosensitive surfaces, and the positions of the emergent light beams of the waveguides in the waveguide array and the positions of the photosensitive surfaces on the DBR medium layers can be accurately controlled.

S1209: and fixing the optical waveguide array on the metal base by using the fixing component.

By adopting the coupling method of the SNSPD array and the optical waveguide array, the unit optical waveguides in the optical waveguide array and the unit SNSPDs in the SNSPD array are vertically aligned and coupled one by one, so that the mutual series interference can be reduced, the simultaneous detection of multiple paths of photons can be realized, the complicated manipulation of the photons can be performed by utilizing the waveguides in the optical waveguide array, and the coupling method has the advantages of expandable scale, high integration rate and low loss.

The present invention is not intended to be limited to the particular embodiments shown and described, but is to be accorded the widest scope consistent with the principles and novel features herein disclosed.