An integrated hollow core fiber-semiconductor optical amplifier coupling device

Abstract

The application discloses a coupling device of an integrated hollow optical fiber-semiconductor optical amplifier, belongs to the technical field of optical fiber communication, optoelectronic device packaging, SOA and hollow optical fiber device, and relates to a coupling device of an integrated hollow optical fiber-semiconductor optical amplifier, which comprises an SOA chip, a hollow optical fiber, a coupling optical assembly, a packaging shell and a temperature control module, wherein the SOA chip is used for receiving a divergent light beam output by the SOA chip, modulating the divergent light beam into a focused light beam matched with a hollow optical fiber guided mode, and enabling the light beam to be coupled into the hollow optical fiber. The coupling device can realize high-efficiency matching between the SOA output light beam and the hollow optical fiber guided mode, and can simultaneously compare direct coupling, single-lens coupling and double-lens coupling. Based on output power and mode matching, it is concluded that single-lens coupling is the optimal integrated scheme when the double-lens coating and optical path are not optimized, and single-lens coupling can realize higher output power and improve the integration repeatability and reliability.

Description

Technical Field

[0001] This invention relates to the fields of optical fiber communication, optoelectronic device packaging, SOA and hollow fiber devices, and more specifically, to an integrated hollow fiber-semiconductor optical amplifier coupling device. Background Technology

[0002] Hollow-core optical fiber is a novel type of optical fiber that uses an air core region as the main light-guiding area. Compared with traditional solid-core silica optical fiber, the interaction between the light field and the solid material in hollow-core optical fiber is significantly reduced, thus exhibiting advantages such as low latency, low nonlinearity, high power carrying capacity, and wide spectrum transmission. It has significant application prospects in high-speed optical communication, microwave photonics, high-power optical transmission, laser transmission, and special sensing.

[0003] Hollow-core optical fibers are limited by device integration in system applications. Their unique air-core structure causes differences in mode field distribution, end-face structure, numerical aperture, and coupling sensitivity compared to traditional single-mode optical fibers, making efficient coupling with active devices such as semiconductor light sources, modulators, detectors, and SOAs more challenging.

[0004] SOA (Optical Amplifier) ​​is a compact electrically pumped optical gain device with advantages such as small size, fast response speed, adjustable current, wide gain bandwidth, and easy packaging and integration, making it suitable for miniaturized optical amplification modules. Efficient integration of SOA with hollow-core fiber can provide active gain compensation for hollow-core fiber communication links and functionalized systems.

[0005] Currently, existing SOA packaging technologies are mainly geared towards traditional single-mode fiber or polarization-maintaining fiber. There is a lack of research on the integration of hollow fiber with SOA devices, especially a lack of system comparisons of direct coupling, single-lens coupling, and dual-lens coupling, as well as the selection of optimal integration schemes based on output power and mode matching.

[0006] Therefore, in view of this, we have studied and improved the existing structure to provide an integrated hollow fiber-semiconductor optical amplifier coupling device, in order to achieve a more practical purpose. Summary of the Invention

[0007] 1. Technical problems to be solved To address the problems existing in the prior art, the present invention aims to provide an integrated coupling device for a hollow fiber-semiconductor optical amplifier (SOA). This device can achieve efficient matching between the SOA output beam and the hollow fiber guided mode. Furthermore, a systematic comparison of direct coupling, single-lens coupling, and dual-lens coupling is conducted. Based on output power and mode matching, it is determined that, without optimizing the dual-lens coating and optical path, single-lens coupling is the preferred integration scheme, which can achieve higher output power and improve integration repeatability and reliability.

[0008] 2. Technical Solution To solve the above problems, the present invention adopts the following technical solution.

[0009] An integrated hollow fiber-semiconductor optical amplifier coupling device, the coupling device comprising: SOA chip: Used to receive the divergent beam output by the SOA chip and modulate the divergent beam into a focused beam that matches the hollow fiber guiding mode, so that the beam is coupled into the hollow fiber. Hollow-core optical fiber: positioned in the light-emitting direction of the SOA chip; Coupled optical component: Located between the output end of SOA chip and the input end of hollow fiber, it is used to receive the divergent beam output by SOA chip and modulate the divergent beam into a focused beam that matches the guided mode of hollow fiber, so that the beam is coupled into hollow fiber. Encapsulation housing: used to fix SOA chip, hollow fiber and coupling optical components; Temperature control module: It is bonded to the SOA chip and is used to regulate the operating temperature of the SOA chip to ensure operational stability.

[0010] Furthermore, the coupling optical component is a single-lens coupling structure, including a focusing lens, which is disposed between the SOA chip and the hollow fiber. The focusing lens is one of the following: spherical lens, aspherical lens, self-focusing lens, cylindrical lens, or microlens. The focusing lens focuses the output beam of the SOA chip into the air core region of the hollow fiber.

[0011] Furthermore, the coupling optical component is a dual-lens coupling structure, comprising a first lens and a second lens; The first lens is used to collimate the output beam of the SOA chip, and the second lens is used to focus the collimated beam onto the core region of the hollow fiber. An anti-reflective coating layer is provided on at least one surface of the first lens or the second lens.

[0012] Furthermore, the hollow-core optical fiber includes, but is not limited to, any one of hollow-core anti-resonant optical fiber, hollow-core photonic bandgap optical fiber, nested hollow-core optical fiber, and negative curvature hollow-core optical fiber.

[0013] Furthermore, the SOA chip is mounted on any surface of a heat sink, temperature control platform, or packaging substrate; The coupling device may also include one or more of the following: an input optical fiber, an input coupling component, an optical isolation component, a polarization control component, a temperature control component, a current drive component, or a package housing.

[0014] Furthermore, the SOA chip is an InP-based active waveguide structure with an output end face beveled and coated with an anti-reflection film, and is mounted on a packaging base or temperature control platform.

[0015] Furthermore, the hollow optical fiber is an anti-resonant hollow optical fiber, positioned in the light-emitting direction of the SOA chip.

[0016] Furthermore, the coupling device employs an active alignment package.

[0017] 3. Beneficial effects Compared with the prior art, the advantages of this invention are: This solution achieves efficient matching between the SOA output beam and the hollow fiber guided mode through an integrated hollow fiber-semiconductor optical amplifier coupling device. At the same time, a systematic comparison is made between direct coupling, single-lens coupling, and dual-lens coupling. Based on output power and mode matching, it is concluded that single-lens coupling is the preferred integration solution when the dual-lens coating and optical path are not optimized, as it can achieve higher output power and improve integration repeatability and reliability. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the coupling method for a hollow fiber amplifier, where: Figure 1 (a) is a directly coupled structure; Figure 1 (b) is a single-lens coupling structure; Figure 1 (c) is a dual-lens coupling structure; Figure 2 The image shows the amplified spontaneous emission (ASE) spectrum and optical power-current-voltage (LIV) curve of a hollow fiber SOA with a single-lens coupling structure. Figure 3 This is a gain curve of a hollow fiber SOA with a single-lens coupling structure. Figure 4 This is a graph showing the relationship between input power and output power in a hollow fiber SOA with a single-lens coupling structure. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0020] Example 1: Please see Figures 1-4 A coupling device for an integrated hollow fiber-semiconductor optical amplifier, the coupling device comprising: SOA chip: Used to receive the divergent beam output by the SOA chip and modulate the divergent beam into a focused beam that matches the hollow fiber guiding mode, so that the beam is coupled into the hollow fiber. Hollow-core optical fiber: positioned in the light-emitting direction of the SOA chip; Coupled optical component: Located between the output end of SOA chip and the input end of hollow fiber, it is used to receive the divergent beam output by SOA chip and modulate the divergent beam into a focused beam that matches the guided mode of hollow fiber, so that the beam is coupled into hollow fiber. Encapsulation housing: used to fix SOA chip, hollow fiber and coupling optical components; Temperature control module: It is bonded to the SOA chip and is used to regulate the operating temperature of the SOA chip to ensure operational stability.

[0021] Specifically, the hollow-core optical fiber includes, but is not limited to, any one of hollow-core anti-resonant optical fiber, hollow-core photonic bandgap optical fiber, nested hollow-core optical fiber, and negative curvature hollow-core optical fiber.

[0022] Hollow-core optical fibers can be selected from other air-core light-guiding structure optical fibers.

[0023] Specifically, the SOA chip is mounted on any surface of a heat sink, temperature control platform, or packaging substrate; The coupling device may also include one or more of the following: an input optical fiber, an input coupling component, an optical isolation component, a polarization control component, a temperature control component, a current drive component, or a package housing.

[0024] Specifically, the SOA chip is an InP-based active waveguide structure with an output end face beveled and coated with an anti-reflective film, and is mounted on a packaging base or temperature control platform.

[0025] Specifically, the hollow optical fiber is an anti-resonant hollow optical fiber, which is placed in the light output direction of the SOA chip; The coupling device uses an active alignment package.

[0026] Drive the SOA chip to output ASE light or signal light, adjust the position of the focusing lens and hollow fiber, fix each component with the maximum output power as the criterion, and complete the integration.

[0027] After packaging, the test conditions for optical performance testing of the single-lens coupling device are as follows: Operating temperature 25℃, operating wavelength 1550 nm, bias current 250 mA: The test items include: amplified spontaneous emission (ASE) spectrum, gain characteristics, and input-output power characteristics.

[0028] in: Amplified spontaneous emission (ASE) spectral testing: The spectrum at the output of the device was recorded using a spectrometer, and the results are as follows: Figure 2 As shown in the figure, the spectrum indicates that the coupling device exhibits good spectral flatness within its operating band, with a spectral ripple amplitude of 2 dB, demonstrating effective suppression of internal optical feedback and high operational stability.

[0029] Gain characteristic test: A signal light of a specified power is input to the SOA chip, and the signal light power at the output of the hollow fiber is recorded. The device gain is then calculated. The test results are as follows: Figure 3 As shown, at a wavelength of 1550 nm, the maximum gain of the coupling device reaches 15.1 dB, which can meet the gain compensation requirements of the hollow-core optical fiber communication system.

[0030] Input-output power characteristic test: By changing the input signal optical power and recording the corresponding output optical power, the input-output power curve is obtained, as shown in the figure. Figure 4 As shown in the figure, the curve indicates that the coupling device has a clear linear amplification region and saturation output characteristics, excellent small-signal amplification performance, and stable power response.

[0031] Tests showed that the input coupling efficiency of the single-lens coupling device described in this embodiment can reach up to 90.99%, achieving efficient and stable coupling between the SOA chip and hollow fiber in the 1550 nm band. The overall performance meets the engineering application requirements of high-speed optical communication, optical interconnection and photonic integrated systems.

[0032] Example 2: Based on the above embodiment 1, further description is provided.

[0033] Specifically, the coupling optical components can be selected as follows: When a single-lens coupling structure is selected, it includes a focusing lens, which is located between the SOA chip and the hollow fiber. The focusing lens is one of a spherical lens, an aspherical lens, a self-focusing lens, a cylindrical lens, or a microlens. The focusing lens focuses the output beam of the SOA chip into the air core region of the hollow fiber.

[0034] When a dual-lens coupling structure is selected, it includes a first lens and a second lens; the first lens is used to collimate the output beam of the SOA chip, and the second lens is used to focus the collimated beam onto the core region of the hollow fiber; at least one surface of the first lens or the second lens is provided with an anti-reflection coating layer to reduce the reflection and feedback light from the lens surface.

[0035] Example 3: Further description is provided based on the above embodiments 1 and 2.

[0036] The specific implementation steps for integrating coupling devices are as follows: Step S1: Prepare SOA chip, hollow fiber and coupling optical components; Step S2: Fix the SOA chip to the packaging base, heat sink or temperature control platform, with the output end facing the hollow fiber input end; Step S3: Place the coupling optical component between the SOA chip output and the hollow fiber input. Step S4: Drive the SOA chip to amplify the spontaneous emission light or amplify the input optical signal; Step S5: Adjust the relative position of the coupling optical component and the hollow fiber, and monitor the output power of the hollow fiber output end in real time. Step S6: When the output power reaches the maximum value or meets the preset coupling efficiency, fix the coupling optical component and the hollow fiber to obtain a coupling device integrating the hollow fiber and SOA.

[0037] See Figure 1 The specific operations, implementation, and comparisons of the coupling are shown in the table below:

[0038] The table below shows the coupling power of the hollow fiber amplifier:

[0039] Testing showed that under current conditions, single-lens coupling yields the highest output power, followed by dual-lens coupling. Without optimizing the dual-lens coating and optical path, single-lens coupling is the preferred integration solution.

[0040] Working principle: By coupling optical components, the mode matching between the SOA output light and the hollow fiber guided mode is improved, thereby reducing the mode mismatch loss of direct coupling. It offers two coupling schemes: single lens and dual lens. The single lens has a simple structure, fewer alignment degrees of freedom, and low packaging difficulty, and can achieve higher output power. The dual-lens structure can further improve coupling efficiency through optimization of coating, lens spacing, working distance, and focal position, supporting high-performance expansion. An active alignment method is adopted, with output power as the alignment criterion, to improve integration repeatability and reliability; It enables device-level integration and can be used in hollow-core fiber active amplifier modules, low-latency optical communication links, microwave photonic links, high-power optical transmission systems, and integrated photonic systems.

[0041] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concepts, should be covered within the scope of protection of the present invention.

Claims

1. A coupling device for an integrated hollow fiber-semiconductor optical amplifier, characterized in that: The coupling devices include: SOA chip: Used to receive the divergent beam output by the SOA chip and modulate the divergent beam into a focused beam that matches the hollow fiber guiding mode, so that the beam is coupled into the hollow fiber. Hollow-core optical fiber: positioned in the light-emitting direction of the SOA chip; Coupled optical component: Located between the output end of SOA chip and the input end of hollow fiber, it is used to receive the divergent beam output by SOA chip and modulate the divergent beam into a focused beam that matches the guided mode of hollow fiber, so that the beam is coupled into hollow fiber. Encapsulation housing: used to fix SOA chip, hollow fiber and coupling optical components; Temperature control module: It is bonded to the SOA chip and is used to regulate the operating temperature of the SOA chip to ensure operational stability.

2. The coupling device for an integrated hollow fiber-semiconductor optical amplifier according to claim 1, characterized in that: The coupling optical component is a single-lens coupling structure, including a focusing lens, which is located between the SOA chip and the hollow fiber. The focusing lens is one of the following: spherical lens, aspherical lens, self-focusing lens, cylindrical lens, or microlens. The focusing lens focuses the output beam of the SOA chip into the air core region of the hollow fiber.

3. The coupling device for an integrated hollow fiber-semiconductor optical amplifier according to claim 1, characterized in that: The coupling optical component is a dual-lens coupling structure, including a first lens and a second lens; The first lens is used to collimate the output beam of the SOA chip, and the second lens is used to focus the collimated beam onto the core region of the hollow fiber. An anti-reflective coating layer is provided on at least one surface of the first lens or the second lens.

4. The coupling device for an integrated hollow fiber-semiconductor optical amplifier according to claim 1, characterized in that: The hollow fiber includes, but is not limited to, any one of hollow anti-resonant fiber, hollow photonic bandgap fiber, nested hollow fiber, and negative curvature hollow fiber.

5. The coupling device for an integrated hollow fiber-semiconductor optical amplifier according to claim 1, characterized in that: The SOA chip is mounted on any surface of a heat sink, temperature control platform, or packaging base. The coupling device may also include one or more of the following: an input optical fiber, an input coupling component, an optical isolation component, a polarization control component, a temperature control component, a current drive component, or a package housing.

6. The coupling device for an integrated hollow fiber-semiconductor optical amplifier according to claim 1, characterized in that: The SOA chip is an InP-based active waveguide structure with an output end face beveled and coated with an anti-reflection film, and is mounted on a packaging base or temperature control platform.

7. The coupling device for an integrated hollow fiber-semiconductor optical amplifier according to claim 1, characterized in that: The hollow optical fiber is an anti-resonant hollow optical fiber, positioned in the light-emitting direction of the SOA chip.

8. The coupling device for an integrated hollow fiber-semiconductor optical amplifier according to claim 1, characterized in that: The coupling device uses an active alignment package.

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