An optical microcavity coupling structure based on a photonics wire bonded waveguide and its packaging method

Abstract

The present invention discloses an optical microcavity coupling structure based on a photonics wire bonding waveguide and its packaging method. The optical microcavity coupling structure includes a housing, an optical fiber array, and an optical microcavity; the housing includes a base and a top cover, the base is provided with a support platform, and the optical microcavity is fixed on the surface of the support platform; the optical fiber array includes a photonics wire bonding waveguide, the first end of the optical fiber array is fixed on the surface of the support platform, and the bending region of the photonics wire bonding waveguide is coupled with the optical microcavity; the first end of the optical fiber array, the photonics wire bonding waveguide, and the optical microcavity are packaged inside the housing, and the second end of the optical fiber array extends outside the housing. The optical microcavity coupling structure provided by the present invention realizes the efficient evanescent coupling between the PWB and the optical microcavity, packages the photonics wire bonding waveguide and the optical microcavity in the housing, has high coupling precision, high reliability, and strong anti-external interference ability, and provides a solution for the large-scale integration of on-chip optical microcavities and integrated photonics systems.

Description

Technical Field

[0001] The present invention relates to the technical field of optical devices, and in particular to an optical microcavity coupling structure based on a photon circuit bonding waveguide and a packaging method thereof. Background Art

[0002] Optical microcavities with extremely high Q (quality factor) values, thanks to their exceptional light field localization capabilities and ultra-low loss, offer an attractive research platform for a variety of cutting-edge photonic applications. In nonlinear optics, these microcavities can efficiently generate broadband optical frequency combs via the Kerr effect. Their compact size and low power consumption open up new avenues for the realization of chip-scale optical frequency combs. In high-precision metrology, the enhanced interaction length of optical microcavities significantly improves sensor sensitivity, offering unique advantages in applications such as trace gas detection and nanoparticle sensing. In telecommunications systems, high-Q optical microcavities can achieve low-threshold optical parametric oscillation, providing a novel light source solution for wavelength division multiplexing. In microwave photonics, optical microcavities based on dual-color pumping can generate microwave signals with low phase noise and spectral purity superior to traditional electronic methods. Furthermore, by incorporating active frequency stabilization techniques, these microcavities can generate laser output with sub-hertz linewidths, providing an ideal light source for applications such as atomic clocks and coherent communications. Of particular note, combining optical microcavities with atomic transition spectral lines can construct optical frequency references with long-term stability, laying the foundation for the miniaturization of next-generation time and frequency standard systems. These diverse applications are primarily due to the unique physical properties of optical microcavities in terms of enhanced light-matter interaction, mode volume compression, and control of nonlinear effects.

[0003] In addition, as photonic devices develop towards miniaturization and low power consumption, the demand for compactness and low-power threshold nonlinear optical effects is becoming increasingly urgent, further driving the research on integrated and scalable solutions. However, these high-performance optical microcavities face a key challenge in practical applications: the need to find stable, compact, and efficient coupling solutions to replace traditional free-space coupling devices (such as tapered fibers, prisms, and end-face coupling). Although these traditional coupling methods are widely used, they have obvious limitations: tapered fibers have low mechanical strength and are easily affected by environmental vibrations; prism coupling systems are bulky and difficult to integrate; and end-face coupling requires stringent alignment accuracy and lacks long-term stability. Summary of the Invention

[0004] An embodiment of the present invention provides an optical microcavity coupling structure based on a photonic wire bond waveguide and a packaging method thereof. The optical microcavity coupling structure realizes efficient evanescent coupling between a photonic wire bond (PWB) and an optical microcavity, and encapsulates the photonic wire bond waveguide and the optical microcavity in a housing, with high coupling precision, high reliability, and strong anti-interference ability against the outside world, providing a solution for the large-scale integration of on-chip optical microcavities and integrated photonics systems.

[0005] According to one aspect of the present invention, there is provided an optical microcavity coupling structure based on a photonic wire bond waveguide, including a housing, an optical fiber array, and an optical microcavity;

[0006] The housing includes a base and a top cover. The base is provided with a support platform, and the optical microcavity is fixed on the surface of the support platform;

[0007] The first end of the optical fiber array includes a photonic wire bond waveguide in a bent shape. The two ends of the photonic wire bond waveguide are respectively connected to two optical fibers of the optical fiber array. The first end of the optical fiber array is fixed on the surface of the support platform. The bent region of the photonic wire bond waveguide is coupled with the optical microcavity, and the photonic wire bond waveguide is suspended;

[0008] The first end of the optical fiber array, the photonic wire bond waveguide, and the optical microcavity are encapsulated inside the housing formed by the fitting of the base and the top cover, and the second end of the optical fiber array extends outside the housing.

[0009] Optionally, the shape of the photonic wire bond waveguide is U-shaped.

[0010] Optionally, the bending diameter of the photonic wire bond waveguide is 127 μm, the waveguide diameter is 2 μm, and the insertion loss is less than or equal to 2.5 dB.

[0011] Optionally, the shape of the photonic wire bond waveguide includes a spiral shape.

[0012] Optionally, the photonic wire bond waveguide is formed by using a negative photoresist through femtosecond laser direct writing technology or two-photon polymerization direct writing technology.

[0013] Optionally, germanium dioxide is doped in the negative photoresist.

[0014] Optionally, the optical microcavity is fixed on the surface of the support platform through a thermally conductive double-sided adhesive. The optical fiber array includes a glass shell, and the glass shell is fixed on the surface of the support platform through an ultraviolet curable adhesive.

[0015] Optionally, the optical microcavity includes an on-chip integrated silica micro-ring core cavity, the core layer of the silica micro-ring core cavity has a thickness of 8 μm, and the ring diameter is 1630 μm.

[0016] According to another aspect of the present invention, there is provided a packaging method for an optical microcavity coupling structure based on a photonics wire bonding waveguide, for packaging the above-mentioned optical microcavity coupling structure. The packaging method includes:

[0017] Providing a housing, an optical fiber array, and an optical microcavity. The housing includes a base and a top cover. The base is provided with a support platform. The first end of the optical fiber array includes a photonics wire bonding waveguide in a bent shape;

[0018] Fixing the optical microcavity on the surface of the support platform;

[0019] Placing the first end of the optical fiber array on the surface of the support platform. After adjusting the coupling between the photonics wire bonding waveguide and the optical microcavity, fixing the first end of the optical fiber array on the surface of the support platform;

[0020] Packaging the first end of the optical fiber array, the photonics wire bonding waveguide, and the optical microcavity inside the housing formed by fitting the base and the top cover, and the second end of the optical fiber array extends outside the housing.

[0021] Optionally, placing the first end of the optical fiber array on the surface of the support platform. After adjusting the coupling between the photonics wire bonding waveguide and the optical microcavity, fixing the first end of the optical fiber array on the surface of the support platform includes:

[0022] Clamping the optical fiber array with a fixture and placing it on the surface of the support platform;

[0023] Controlling the movement of the base by using a three-dimensional translation stage and a piezoelectric displacement stage to couple the optical microcavity with the bent region of the photonics wire bonding waveguide;

[0024] Monitoring the coupling state between the optical microcavity and the photonics wire bonding waveguide. When the target coupling state is reached, fixing the first end of the optical fiber array on the surface of the support platform;

[0025] Wherein, the photonics wire bonding waveguide is suspended.

[0026] The optical microcavity coupling structure based on the photon wire bonding waveguide provided by the embodiment of the present invention includes a housing, an optical fiber array, and an optical microcavity; the housing includes a base and a top cover, the base is provided with a support platform, the first end of the optical fiber array includes a photon wire bonding waveguide in a bent shape, both ends of the photon wire bonding waveguide are respectively connected to two optical fibers of the optical fiber array, by fixing the optical microcavity and the first end of the optical fiber array on the surface of the support platform, the bent region of the photon wire bonding waveguide is coupled with the optical microcavity, and the photon wire bonding waveguide is suspended; by encapsulating the first end of the optical fiber array, the photon wire bonding waveguide, and the optical microcavity inside the housing formed by fitting the base and the top cover, the second end of the optical fiber array extends to the outside of the housing, enhancing the anti-interference of the coupling between the optical microcavity and the photon wire bonding waveguide, and ensuring the stability of the coupling efficiency and the quality factor of the optical microcavity. The technical solution of the embodiment of the present invention realizes the efficient evanescent coupling between the PWB and the optical microcavity, and provides a solution for the large-scale integration of on-chip optical microcavities and integrated photonics systems. Experimental results show that the coupling structure provided by the embodiment of the present invention achieves a coupling efficiency of more than 90% in the 1550 nm band, while maintaining the intrinsic Q value of the optical microcavity > 10 7 。The PWB technology can flexibly construct low-loss (<2.5 dB) optical interconnection structures in three-dimensional space through additive manufacturing processes such as femtosecond laser direct writing or two-photon polymerization. Its core advantages are reflected in: low manufacturing cost: no complex alignment process is required, and one-step forming solves the problem of precise positioning at the sub-micron level required for traditional cleaved optical fibers; small size: the cross-sectional size can be compressed to 1×2 μm², which is more suitable for high-density integration than traditional tapered optical fibers (typical diameter 10 μm - 20 μm); high mechanical robustness: the polymer structure with a Young's modulus of 3 GPa - 5 GPa has more than 10 times better vibration stability than glass optical fibers; strong functional scalability: supports multimode interference design, and can simultaneously realize microcavity coupling and wavelength multiplexing functions.

[0027] In addition, the coupling architecture provided by the embodiment of the present invention provides a key enabling technology for constructing large-scale nonlinear photonic networks (such as photonic quantum computing chips, parallel optical frequency comb arrays). In the future, through material modification (such as doping to improve the nonlinear coefficient) and topological optimization (such as spiral PWB design), it is beneficial to promote the development of industrial-level photonic integrated circuits.

[0028] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0030] Figure 1 Schematic structural diagram of the housing of an optical microcavity coupling structure provided by an embodiment of the present invention;

[0031] Figure 2 Microscopic structural diagram of an optical fiber array of an optical microcavity coupling structure provided by an embodiment of the present invention;

[0032] Figure 3 Another microscopic structural diagram of the optical fiber array of the optical microcavity coupling structure provided by an embodiment of the present invention;

[0033] Figure 4 Microscopic structural diagram of an optical microcavity of an optical microcavity coupling structure provided by an embodiment of the present invention;

[0034] Figure 5 Microscopic structural diagram of the coupling of a photonic circuit bonding waveguide and an optical microcavity of an optical microcavity coupling structure provided by an embodiment of the present invention;

[0035] Figure 6 Flow schematic diagram of a packaging method for an optical microcavity coupling structure based on a photonic circuit bonding waveguide provided by an embodiment of the present invention;

[0036] Figure 7 Schematic structural diagram of an optical path device when a photonic circuit bonding waveguide is coupled with an optical microcavity provided by an embodiment of the present invention;

[0037] Figure 8 Schematic diagram of the quality factor of the optical microcavity after packaging provided by an embodiment of the present invention;

[0038] Wherein, 10 - housing, 11 - base, 12 - top cover, 111 - support platform, 20 - optical fiber array, 21 - optical fiber, 22 - photonic circuit bonding waveguide, 30 - optical microcavity, 100 - signal generator, 200 - laser, 300 - attenuator, 400 - polarization controller, 500 - beam splitter, 600 - Mach-Zehnder interferometer, 710 - first photodetector, 720 - second photodetector, 800 - oscilloscope. Detailed implementation manners

[0039] To enable those skilled in the art to better understand the solution of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part rather than all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0040] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order different from those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0041] To solve the coupling problem of optical microcavities in the prior art, the embodiments of the present invention provide an optical microcavity coupling structure based on a photonics wire bonding waveguide. This coupling structure encapsulates a photonics wire bonding (PWB) waveguide and an optical microcavity together, providing an alternative and more flexible coupling solution. The optical microcavity coupling structure based on a photonics wire bonding waveguide provided by the embodiments of the present invention includes a housing, an optical fiber array, and an optical microcavity; the housing includes a base and a top cover, the base is provided with a support platform, and the optical microcavity is fixed on the surface of the support platform; the first end of the optical fiber array includes a photonics wire bonding waveguide in a bent shape, both ends of the photonics wire bonding waveguide are respectively connected to two optical fibers of the optical fiber array, the first end of the optical fiber array is fixed on the surface of the support platform, the bent region of the photonics wire bonding waveguide is coupled with the optical microcavity, and the photonics wire bonding waveguide is suspended; the first end of the optical fiber array, the photonics wire bonding waveguide, and the optical microcavity are encapsulated inside the housing formed by the fitting of the base and the top cover, and the second end of the optical fiber array extends outside the housing.

[0042] Exemplarily, Figure 1 is a schematic structural diagram of the housing of an optical microcavity coupling structure provided by the embodiments of the present invention, Figure 2 is a schematic microstructural diagram of the optical fiber array of an optical microcavity coupling structure provided by the embodiments of the present invention, Figure 3 is another schematic microstructural diagram of the optical fiber array of the optical microcavity coupling structure provided by the embodiments of the present invention, Figure 4Schematic diagram of the microstructure of an optical microcavity of an optical microcavity coupling structure provided by an embodiment of the present invention Figure 5 Schematic diagram of the microstructure of the photon line bonding waveguide and the optical microcavity coupling of an optical microcavity coupling structure provided by an embodiment of the present invention. Refer to Figure 1 , the housing 10 includes a base 11 and a top cover 12. The base 11 is provided with a support platform 111, and the optical microcavity is fixed on the surface of the support platform ills ( Figure 1 The optical microcavity and the fiber array are not shown in Figure 2 and Figure 3 . The fiber array 20 includes a plurality of fibers 21 arranged side by side. The first end of the fiber array 20 includes a photon line bonding waveguide 22 in a bent shape. The two ends of the photon line bonding waveguide 22 are respectively connected to two fibers 21 of the fiber array 20 ( Figure 2 and Figure 3 schematically show the connection between the photon line bonding waveguide 22 and two adjacent fibers 21, which is not a limitation of the present invention). Refer to Figure 4 , the optical microcavity 30 can be an on-chip integrated silica micro-ring core cavity. In this embodiment, the core layer thickness of the silica micro-ring core cavity is 8 μm, and the ring diameter is 1630 μm. The optical microcavity 30 further includes a substrate and support pillars for supporting the silica micro-ring core cavity ( Figure 4 not shown in Figure 5 ). The materials of the substrate and the support pillars can be silicon. In other embodiments, the specific dimensions of the optical microcavity 30 can be designed according to actual situations. Combining Figure 5 , during coupling, the first end of the fiber array 20 and the optical microcavity 30 are fixed on the surface of the support platform 111. Optionally, the optical microcavity 30 can be fixed on the surface of the support platform 111 through a thermally conductive double-sided adhesive. The fiber array 20 includes a glass outer shell, and the glass outer shell is fixed on the surface of the support platform 111 through an ultraviolet curable adhesive. The bent region of the photon line bonding waveguide 22 is coupled with the optical microcavity 30, and the photon line bonding waveguide 22 is suspended. After coupling is completed, the first end of the fiber array 20, the photon line bonding waveguide 22, and the optical microcavity 30 are encapsulated inside the housing 10 formed by the fitting of the base 11 and the top cover 12, and the second end of the fiber array 20 extends outside the housing 10.

[0043] Among them, PWB is an additive 3D manufacturing structure that can guide light in a free-form configuration. Using a proprietary negative photoresist, similar to SU-Il, these PWBs can be directly written arbitrarily on the surface of fiber arrays (FAs) or even PICs through a two-photon polymerization process.

[0044] In the technical solution of the embodiment of the present invention, by fixing the optical microcavity and the first end of the fiber array on the surface of the support platform, the bending region of the photonics circuit bonding waveguide is coupled with the optical microcavity, and the photonics circuit bonding waveguide is suspended; by encapsulating the first end of the fiber array, the photonics circuit bonding waveguide and the optical microcavity inside the housing formed by the fitting of the base and the top cover, and the second end of the fiber array extends outside the housing, the anti-interference performance of the coupling between the optical microcavity and the photonics circuit bonding waveguide is enhanced, and the stability of the coupling efficiency and the quality factor of the optical microcavity is ensured. The technical solution of the embodiment of the present invention realizes the efficient evanescent coupling between the PWB and the optical microcavity, and provides a solution for the large-scale integration of the on-chip optical microcavity and the integrated photonics system. Compared with the coupling between the PWB and the crystal, the optical microcavity provided by the embodiment of the present invention is on-chip integrated, which is more conducive to mass production and cost reduction.

[0045] Continue to refer to Figure 2 and Figure 3 , optionally, the shape of the photonics circuit bonding waveguide 22 is U-shaped. Optionally, the bending diameter of the photonics circuit bonding waveguide 22 is 127 μm, the waveguide diameter is 2 μm, and the insertion loss is less than or equal to 2.5 dB.

[0046] Optionally, the photonics circuit bonding waveguide is formed by negative photoresist through femtosecond laser direct writing technology or two-photon polymerization direct writing technology.

[0047] In specific implementation, a U-shaped bent waveguide PWB structure as shown in Figure 2 and Figure 3 is prepared on the end face of a customized fiber array (FA) by two-photon polymerization direct writing technology using negative photoresist. The key parameters of this structure are as follows: U-shaped bending diameter: 127 μm (matched with the standard fiber array spacing), waveguide wire diameter: 2 μm, insertion loss: 2.5 dB (including fiber-PWB-fiber end-to-end loss).

[0048] Furthermore, in other embodiments, the nonlinear coefficient and topological optimization can be improved through material modification, which is beneficial to promoting the development of industrial-level photonic integrated circuits. Exemplarily, germanium dioxide ( ) can be doped in the negative photoresist to improve the nonlinear coefficient of the PWB, and the shape of the photonics circuit bonding waveguide can be set to include a spiral shape, which can be designed according to the actual situation in specific implementation.

[0049] Using Figure 2 the shown fiber array and Figure 4 the shown optical microcavity for coupling. Before coupling, the evanescent field mode distribution of the prepared PWB bent waveguide is simulated using commercial optical simulation software to optimize its coupling efficiency with the optical microcavity.

[0050] Figure 6A flowchart of a packaging method for an optical microcavity coupling structure based on a photon line bonded waveguide provided by an embodiment of the present invention, which is used to package the optical microcavity coupling structure provided by the above embodiment, refer to Figure 6 , the packaging method includes:

[0051] S110. Provide a housing, an optical fiber array, and an optical microcavity. The housing includes a base and a top cover. The base is provided with a support platform. The first end of the optical fiber array includes a photon line bonded waveguide in a bent shape.

[0052] Among them, the housing refer to Figure 1 As shown, the housing is manufactured by a numerically controlled machine tool (CNC) of aluminum alloy and is composed of a base 11 and a top cover 12. The design of the packaging housing mainly follows three design elements: flexible operation, stable coupling structure, and isolation from the outside. The optical fiber array refer to Figure 2 and Figure 3 As shown, a U-shaped bent waveguide PWB structure is prepared on the end face of a customized optical fiber array (FA) by two-photon polymerization direct writing technology using a negative photoresist. The key parameters of this structure are as follows: U-shaped bending diameter: 127 μm (matched with the spacing of the standard optical fiber array), waveguide diameter: 2 μm, insertion loss: 2.5 dB (including the end-to-end loss of fiber-PWB-fiber). The optical microcavity refer to Figure 4 As shown, in this embodiment, the optical microcavity is an on-chip integrated silica micro-ring core cavity. The core layer thickness of the silica micro-ring core cavity is 8 μm, and the ring diameter is 1630 μm ( before reflow).

[0053] S120. Fix the optical microcavity on the surface of the support platform.

[0054] Specifically, it can be fixed on the surface of the support platform by using a thermally conductive double-sided tape.

[0055] S130. Place the first end of the optical fiber array on the surface of the support platform. After adjusting the coupling between the photon line bonded waveguide and the optical microcavity, fix the first end of the optical fiber array on the surface of the support platform.

[0056] After fixing the optical microcavity, place the base with the fixed microcavity sample on a precision displacement stage. Figure 7 A schematic structural diagram of an optical path device when the photon line bonded waveguide provided by an embodiment of the present invention is coupled with the optical microcavity, refer to Figure 7, the optical path device includes a signal generator 100, a laser 200, an attenuator 300, a polarization controller 400, a beam splitter 500, a Mach-Zehnder interferometer 600, a first photodetector 710, a second photodetector 720, and an oscilloscope 800. The photon line bonding waveguide 22 is connected into the optical path, and the optical microcavity 30 is disposed close to the photon line bonding waveguide 22. The signal generator 100 is used to provide a scanning piezoelectric signal to the laser 200. The light beam emitted by the laser 200 is incident on the beam splitter 500 after being attenuated by the attenuator 300 and the polarization state is adjusted by the polarization controller 400. The beam splitter 500 can be a 10:90 beam splitter, 10% of the light intensity is transmitted to the Mach-Zehnder interferometer 600, and 90% of the light intensity is transmitted to the photon line bonding waveguide 22. The coupling condition is determined by monitoring the signals of the first photodetector 710 and the second photodetector 720 received by the oscilloscope 800.

[0057] Optionally, placing the first end of the fiber array on the surface of the support platform, after adjusting the coupling between the photon line bonding waveguide and the optical microcavity, fixing the first end of the fiber array on the surface of the support platform, including:

[0058] S131. Clamping the fiber array with a fixture and placing it on the surface of the support platform.

[0059] Wherein, the fiber array further includes a glass outer shell. First, clamp the fiber array with a fixture, place the first end of the fiber array on the surface of the support platform, and make the photon line bonding waveguide and the optical microcavity at a relatively close position.

[0060] S132. Controlling the movement of the base by using a three-dimensional translation stage and a piezoelectric displacement stage so that the optical microcavity is coupled with the bending region of the photon line bonding waveguide.

[0061] When controlling the movement of the base, simultaneously observe Figure 7 the waveform of the oscilloscope 800, and judge the coupling condition between the optical microcavity and the photon line bonding waveguide according to the waveform.

[0062] S133. Monitoring the coupling state between the optical microcavity and the photon line bonding waveguide. When the target coupling state is reached, fix the first end of the fiber array on the surface of the support platform.

[0063] Wherein, the photon line bonding waveguide is suspended. When the target coupling state is reached, apply an ultraviolet curable adhesive EMI 3410 between the glass outer shell of the fiber array and the base of the housing, and fix the fiber array on the base of the housing by ultraviolet irradiation, and fix the coupling between the silica micro-ring core cavity and the PWB bent waveguide structure.

[0064] S140. Enclose the first end of the fiber array, the photon line bonding waveguide and the optical microcavity inside the housing formed by the fitting of the base and the top cover, and the second end of the fiber array extends outside the housing.

[0065] Figure 8 Schematic diagram of the quality factor of the packaged optical microcavity provided by the embodiment of the present invention, where the intrinsic quality factor of the optical microcavity = 3.3×10 7 , and the coupling quality factor Q = 2.6×10 7 . The experimental results show that the coupling structure provided by the embodiment of the present invention achieves a coupling efficiency of more than 90% in the 1550 nm band, while maintaining the intrinsic Q value of the optical microcavity > 10 7 . Through additive manufacturing processes such as femtosecond laser direct writing or two-photon polymerization, the PWB technology can flexibly construct low-loss (<2.5 dB) optical interconnection structures in three-dimensional space. Its core advantages are reflected in: low manufacturing cost: no complex alignment process is required, and single-step forming solves the problem of sub-micron-level precise positioning required for traditional cleaved optical fibers; small size: the cross-sectional size can be compressed to 1×2 μm², which is more suitable for high-density integration than traditional tapered optical fibers (typical diameter 10 μm - 20 μm); high mechanical robustness: the polymer structure with a Young's modulus of 3 GPa - 5 GPa has more than 10 times higher vibration stability than glass optical fibers; strong functional scalability: supports multimode interference design and can simultaneously realize microcavity coupling and wavelength multiplexing functions.

[0066] In addition, the coupling architecture provided by the embodiment of the present invention provides a key enabling technology for constructing large-scale nonlinear photonic networks (such as photonic quantum computing chips, parallel optical frequency comb arrays). In the future, through material modification (such as doping to increase the nonlinear coefficient) and topological optimization (such as spiral PWB design), it is beneficial to promote the development of industrial-level photonic integrated circuits.

[0067] The above specific embodiments do not constitute a limitation to the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An optical microcavity coupling structure based on a photon line bonding waveguide, characterized in that It includes a housing, an optical fiber array, and an optical microcavity; The housing includes a base and a top cover. The base is provided with a support platform, and the optical microcavity is fixed on the surface of the support platform; The first end of the optical fiber array includes a photon line bonding waveguide in a bent shape. Both ends of the photon line bonding waveguide are respectively connected to two optical fibers of the optical fiber array. The first end of the optical fiber array is fixed on the surface of the support platform. The bent region of the photon line bonding waveguide is coupled with the optical microcavity, and the photon line bonding waveguide is suspended; The first end of the optical fiber array, the photon line bonding waveguide, and the optical microcavity are encapsulated inside the housing formed by the fitting of the base and the top cover, and the second end of the optical fiber array extends to the outside of the housing; Wherein, the shape of the photon line bonding waveguide is U-shaped or spiral-shaped, and the optical microcavity is an on-chip integrated optical microcavity.

2. The optical microcavity coupling structure based on a photon line bonded waveguide according to claim 1, wherein The bending diameter of the photon line bonding waveguide is 127 μm, the waveguide diameter is 2 μm, and the insertion loss is less than or equal to 2.5 dB.

3. The optical microcavity coupling structure based on a photon line-bonded waveguide according to claim 1, wherein The photon line bonding waveguide is formed by negative photoresist through femtosecond laser direct writing technology or two-photon polymerization direct writing technology.

4. The optical microcavity coupling structure based on a photonic wire bonded waveguide according to claim 3, characterized in that Germanium dioxide is doped in the negative photoresist.

5. The optical microcavity coupling structure based on a photon line-bonded waveguide according to claim 1, wherein The optical microcavity is fixed on the surface of the support platform through a thermally conductive double-sided adhesive. The optical fiber array includes a glass outer shell, and the glass outer shell is fixed on the surface of the support platform through an ultraviolet curable adhesive.

6. The optical microcavity coupling structure based on a photon line-bonded waveguide according to claim 1, wherein The optical microcavity includes an on-chip integrated silica micro-ring core cavity. The core layer thickness of the silica micro-ring core cavity is 8 μm, and the ring diameter is 1630 μm.

7. A packaging method for an optical microcavity coupling structure based on a photon line bonding waveguide, characterized in that For encapsulating the optical microcavity coupling structure according to any one of claims 1 to 6, the encapsulation method includes: Providing a housing, an optical fiber array, and an optical microcavity. The housing includes a base and a top cover. The base is provided with a support platform, and the first end of the optical fiber array includes a photon line bonding waveguide in a bent shape; Fixing the optical microcavity on the surface of the support platform; Placing the first end of the optical fiber array on the surface of the support platform. After adjusting the coupling of the photon line bonding waveguide and the optical microcavity, fixing the first end of the optical fiber array on the surface of the support platform; Encapsulating the first end of the optical fiber array, the photon line bonding waveguide, and the optical microcavity inside the housing formed by the fitting of the base and the top cover, and the second end of the optical fiber array extends to the outside of the housing.

8. The encapsulation method according to claim 7, wherein Placing the first end of the optical fiber array on the surface of the support platform. After adjusting the coupling of the photon line bonding waveguide and the optical microcavity, fixing the first end of the optical fiber array on the surface of the support platform includes: Clamping the optical fiber array with a fixture and placing it on the surface of the support platform; Controlling the movement of the base by using a three-dimensional translation stage and a piezoelectric displacement stage to couple the optical microcavity with the bent region of the photon line bonding waveguide; Monitoring the coupling state of the optical microcavity and the photon line bonding waveguide. When the target coupling state is reached, fixing the first end of the optical fiber array on the surface of the support platform; Wherein, the photon line bonding waveguide is suspended.

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