Optical receiving assembly and optical module

Abstract

The utility model relates to the technical field of optical communication, in particular to an optical receiving assembly and an optical module, which comprise an AWG chip, a glass cover plate, an optical fiber capillary tube, a cushion block, a photoelectric detector and a circuit board, the glass cover sheet is fixedly arranged on the upper surface of the AWG chip, the optical fiber capillary tube is coupled with one end of the AWG chip, the cushion block is fixedly arranged on the lower surface of the AWG chip, and the cushion block and the photoelectric detector are fixedly arranged on the circuit board; one end of the AWG chip is provided with an integrated lens, the integrated lens is arranged on the opposite side of the optical fiber capillary, the integrated lens is located above the photoelectric detector, and the center of the integrated lens and the center of the photoelectric detector are located on the same straight line. The integrated lens is directly processed and arranged at the bottom of the AWG chip, so that the reflected and divergent optical signal can be reconverged into the photoelectric detector, light spot compression with the same effect as that of an additional lens can be achieved, and the overall structure of the optical receiving assembly is simplified.

Description

TECHNICAL FIELD

[0001] The utility model relates to optical communication technical field especially relates to a kind of optical receiving assembly and optical module. BACKGROUND

[0002] In the optical transceiver module above 2km, Arrayed Waveguide Grating (AWG) integrated optical chip is a kind of device that can realize simple optical splitting function, often used as part of optical signal processing system, used with optical receiving assembly such as Photodetector (PD). Optical signal enters AWG chip 1' through optical fiber, and is split by AWG chip 1', separates multiple wavelengths and is input into multiple PDs 2', to complete signal transmission. The commonly used optical receiving assembly structure is shown in Figure 1 , the end face of AWG chip 1' is polished into bevel 40~42 degrees, and the optical signal is reflected into the photosensitive surface of PD 2' by total reflection, to complete the transmission of optical path. Since the PD 2' rate of single-mode optical device is higher, the photosensitive surface is smaller, for single-channel 100Gbit / s optical device, the photosensitive surface diameter of PD 2' is usually only 20um, even 16um, and the light divergence angle reflected by the end face of AWG chip 1' is large, which will be rapidly expanded after a short distance, exceeding the size of photosensitive surface, and the coupling efficiency is low. At the same time, in order to reduce the loss of optical energy, as shown in Figure 1 , it is necessary to direct the waveguide layer of AWG chip 1' to the photosensitive surface of PD 2' to realize the near distance coupling within 30um. Since the distance is too close, the waveguide layer surface of AWG chip 1' cannot be protected by glass cover, and the waveguide layer is easy to be damaged in the polishing process, there are problems of complex polishing process of AWG chip 1', easy to break the reflection end face, high requirements for coupling equipment precision and bonding process. In addition, in order to avoid the above defects, lens 3' can be used to converge the divergent light of AWG chip 1', as shown in Figure 2 , since the lens 3' is added, the distance and tolerance of AWG chip 1' from PD 2' are increased, which can avoid the defects of the previous scheme, but this scheme increases the lens 3' and the lens support 4', and needs to align the lens 3', the structure is complex, increases the manufacturing complexity and the cost of module.

[0003] Therefore, it is urgent to overcome the defects of the prior art in the technical field. UTILITY MODEL CONTENTS

[0004] The technical problem to be solved by the utility model is that the existing AWG optical receiving assembly needs to be additionally provided with lens support, which leads to complex structure and large size of optical receiving assembly.

[0005] The utility model provides a kind of optical receiving assembly, it include: AWG chip 1, glass cover 2, optical fiber capillary 3, cushion block 4, photoelectric detector 5 and circuit board 6;The glass cover 2 is fixedly arranged on the upper surface of the AWG chip 1, the optical fiber capillary 3 is coupled with one end of the AWG chip 1, the cushion block 4 is fixedly arranged on the lower surface of the AWG chip 1, the cushion block 4 and the photoelectric detector 5 are fixedly arranged on the circuit board 6;

[0006] One end of the AWG chip 1 is processed and set with integrated lens 10, the integrated lens 10 is arranged on the opposite side of the optical fiber capillary 3, the integrated lens 10 is located above the photoelectric detector 5, the center of the integrated lens 10 and the center of the photoelectric detector 5 are located on the same straight line.

[0007] Preferably, the AWG chip 1 further includes a waveguide layer 11 and a silicon-based substrate 12, the waveguide layer 11 is located between the glass cover 2 and the silicon-based substrate 12, the silicon-based substrate (12) is located on the cushion block 4; the integrated lens 10 is etched on the silicon-based substrate 12.

[0008] Preferably, after the waveguide layer 11 and the glass cover 2 are bonded, the two ends of the AWG chip 1 and the glass cover 2 are polished at a preset angle to form a reflection end face 13 and a coupling end face 14.

[0009] Preferably, the polishing angle of the reflection end face 13 is 40-42 degrees, and the reflection end face 13 is used for reflecting the optical signal into the photoelectric detector 5.

[0010] Preferably, the thickness of the silicon-based substrate 12 is 0.6-0.7 mm.

[0011] Preferably, the AWG chip 1 is formed by processing and cutting a silicon wafer, and the size of the silicon wafer is one of 6 inches or 8 inches.

[0012] Preferably, the material of the cushion block 4 is one of a ceramic sheet or a glass sheet, the difference between the expansion coefficient of the cushion block 4 and the expansion coefficient of the AWG chip 1 is less than a preset value, and the thickness of the cushion block 4 can make the optical signal pass through the integrated lens 10 to form a light spot into the photoelectric detector 5.

[0013] Preferably, the polishing angle of one end of the AWG chip 1 coupled with the optical fiber capillary 3 is 7-8 degrees.

[0014] Preferably, the thickness of the glass cover 2 is 0.1-0.2 mm.

[0015] The utility model provides a kind of optical module, including the optical receiving component 7 and light emitting component 8 of the first aspect described, the light emitting component 8 is used to emit optical signal, the optical receiving component 7 is used to receive return optical signal.

[0016] Compared with the prior art, the utility model has the beneficial effects that: the optical receiving component provided by the utility model can re-converge the dispersed optical signal after reflection into the photodetector 5 by directly processing and arranging the integrated lens 10 on the bottom of the AWG chip 1, so that the spot size is smaller than the photosensitive surface size of the photodetector 5, the coupling efficiency is improved, and the integrated lens 10 is directly etched on the AWG chip 1, which can simplify the structure of the optical receiving component 7 as a whole and reduce the size of the optical receiving component 7; meanwhile, the problem of close contact between the AWG chip 1 and the photodetector 5 when they are directly coupled is avoided, and the requirements for coupling precision and bonding process of the AWG chip 1 and the photodetector 5 are lower. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the drawings needed to be used in the embodiments of the utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model, and other drawings can be obtained according to these drawings without creative labor for those skilled in the art.

[0018] Figure 1 is the overall structure schematic diagram of the first existing optical receiving component provided by the embodiments of the utility model;

[0019] Figure 2 is the overall structure schematic diagram of the second existing optical receiving component provided by the embodiments of the utility model;

[0020] Figure 3 is the overall structure schematic diagram of the optical receiving component provided by the embodiments of the utility model;

[0021] Figure 4 is the structure schematic diagram of the AWG chip of the optical receiving component provided by the embodiments of the utility model;

[0022] Figure 5 is the schematic diagram of the coupling end face of the optical receiving component provided by the embodiments of the utility model;

[0023] Figure 6 is the schematic diagram of the optical module suitable for the optical receiving component provided by the embodiments of the utility model;

[0024] Figure 7It is the whole structure schematic view of the light receiving assembly of the light receiving assembly provided by the embodiment of the utility model.

[0025] Wherein, the reference numerals are:

[0026] 1-AWG chip, 10-integrated lens, 11-waveguide layer, 12-silicon substrate, 13-reflective end face, 14-coupling end face, 2-glass cover, 3-optical fiber capillary, 4-pad, 5-optical detector, 6-circuit board, 7-light receiving assembly, 8-light emitting assembly. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantage of the utility model more clearly, the following is combined with the drawing and embodiment, and the utility model is further described in detail.It should be understood that the specific embodiments described herein are only used to explain the utility model, and are not used to limit the utility model.

[0028] Unless otherwise required by context, the term "comprises" in the specification and claims is to be construed as open-ended, i.e., as "comprises but not limited to".In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example" or "some examples" are intended to mean that the specific features, structures, materials or characteristics related to the embodiment or example include in at least one embodiment or example of the present disclosure.The illustrative representation of the above terms does not necessarily mean the same embodiment or example.In addition, the specific features, structures, materials or characteristics described can be included in any one or more embodiments or examples in any appropriate manner, i.e., although they are carried in the embodiment or example of the above terms due to the order of appearance and location, they are not limited to the combination of one embodiment or example.

[0029] In the description of the utility model, it is understood that the orientation or position relationship indicated by the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present disclosure and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present disclosure.

[0030] In the description of the utility model, the terms "first", "second" are only used for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more features. In the description of the embodiments of the present disclosure, unless otherwise specified, the meaning of "multiple" is two or more. In addition, for example, in the description, the same type of nouns will also be described as two independent individuals by adding "A", "B" at the end, in which case the features limited by "A", "B" are only used for the purpose of distinguishing the same type of individual description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features.

[0031] In describing some embodiments, "coupled", "coupled", and "connected" and their derivatives can be used. For example, the term "connected" can be used to describe some embodiments to indicate that two or more components have direct physical or electrical contact with each other. For another example, the term "coupled" can be used to describe some embodiments to indicate that two or more components have direct physical or electrical contact. However, the term "connected" or "coupled" can also refer to two or more components that do not have direct contact with each other, but still cooperate or interact with each other, such as "optical coupling", "wireless connection", etc. The embodiments disclosed herein are not necessarily limited to the content of the utility model.

[0032] In the description of the utility model, the expression "A and / or B" (wherein A and B are used to represent specific feature content) can be used, and the corresponding expression includes the following three combinations: only A, only B, and the combination of A and B.

[0033] In the utility model, "about", "approximately" or "approximately" includes the value described and the average value within the acceptable deviation range of the specific value, wherein the acceptable deviation range is determined by considering the measurement being discussed and the measurement error related to the specific quantity (i.e. the limitation of the measurement system) by ordinary skilled in the art.

[0034] In addition, the technical features involved in each embodiment of the utility model described below can be combined with each other as long as there is no conflict.

[0035] Embodiment 1:

[0036] The utility model embodiment 1 provides a kind of optical receiving assembly, such as Figure 3As shown, it comprises: an AWG chip 1, a glass cover sheet 2, a fiber capillary 3, a cushion block 4, a photodetector 5 and a circuit board 6; the glass cover sheet 2 is fixedly arranged on the upper surface of the AWG chip 1, the fiber capillary 3 is coupled with one end of the AWG chip 1, the cushion block 4 is fixedly arranged on the lower surface of the AWG chip 1, and the cushion block 4 and the photodetector 5 are fixedly arranged on the circuit board 6; one end of the AWG chip 1 is provided with an integrated lens 10, the integrated lens 10 is arranged on the opposite side of the fiber capillary 3, the integrated lens 10 is located above the photodetector 5, and the center of the integrated lens 10 is located on the same straight line as the center of the photodetector 5. Specifically, the optical signal is input into the AWG chip 1 through the fiber capillary 3, reflected by the AWG chip 1, converged by the integrated lens 10, and finally transmitted into the photosensitive surface of the photodetector 5, thereby completing the transmission of the optical signal.

[0037] The photodetector 5 and the cushion block 4 can be adhered to the circuit board 6 by using a thermosetting adhesive. When the material is heated, its size will change. The photodetector 5 and the cushion block 4 may be caused to fail to adhere or to have a performance decline due to mechanical stress. Therefore, when the material of the cushion block 4 is selected, the material of the cushion block 4 is one of a ceramic sheet and a glass sheet, the difference between the expansion coefficient of the cushion block 4 and the expansion coefficient of the AWG chip 1 is less than a preset value, the preset value can be 5ppm / ℃, and the thickness of the cushion block 4 can enable the optical signal to pass through the integrated lens 10 to form a light spot and enter the photodetector 5.

[0038] In one embodiment, the expansion coefficient of the cushion block 4 is equal to the expansion coefficient of the AWG chip 1, or the expansion coefficient of the cushion block 4 is slightly greater than the expansion coefficient of the AWG chip 1, or the expansion coefficient of the cushion block 4 is slightly less than the expansion coefficient of the AWG chip 1.

[0039] When the expansion coefficients of the cushion block 4 and the AWG chip 1 are similar, the size changes caused by temperature changes will be relatively consistent, thereby reducing the mechanical stress between the two, helping to maintain the integrity and reliability of the adhesion, and preventing adhesion failure caused by excessive stress. In addition, the matching of the expansion coefficients can also ensure that the relative positions between the cushion block 4 and the AWG chip 1 remain stable when the temperature changes, thereby maintaining the performance stability of the entire assembly.

[0040] In the above scheme, the optical fiber capillary tube 3 is coupled with one end of the AWG chip 1, wherein the polishing angle of the end of the AWG chip 1 coupled with the optical fiber capillary tube 3 is 7-8 degrees. The polishing angle can be any value in 7-8 degrees, which can be determined according to actual conditions, and the embodiment is not limited specifically. The end of the AWG chip 1 coupled with the optical fiber capillary tube 3 is polished, and the polishing angle is 7-8 degrees. The reason is that when light enters from one medium (such as the AWG chip 1) into another medium (such as the optical fiber capillary tube 3), reflection will occur at the interface between the two. The polishing angle of 7-8 degrees can guide the reflected light into the cladding of the optical fiber capillary tube 3 instead of returning to the core, thereby reducing the reflection loss, maximizing the transmission efficiency of the optical signal, and ensuring that more optical energy enters the optical fiber and is transmitted along the predetermined path. Secondly, the selection of the polishing angle helps to optimize the optical path design, ensure smooth transition of light between the AWG chip 1 and the optical fiber, and reduce loss and distortion caused by sudden changes in the optical path. In addition, the design of the polishing angle of 7-8 degrees helps to achieve close contact and fixation between the AWG chip 1 and the optical fiber capillary tube 3, thereby reducing the relative displacement caused by vibration or temperature change, and ensuring long-term stable coupling effect.

[0041] The light receiving assembly provided by the embodiment of the utility model can re-converge the divergent light signal after reflection into the photoelectric detector 5, so that the spot size is smaller than the photosensitive surface size of the photoelectric detector 5, the coupling efficiency is improved, the integrated lens 10 is directly etched on the AWG chip 1, the structure of the whole light receiving assembly 7 can be simplified, and the size of the light receiving assembly 7 can be reduced. At the same time, the problem of close contact between the AWG chip 1 and the photoelectric detector 5 when the AWG chip 1 is directly coupled with the photoelectric detector 5 is avoided, and the requirements for coupling precision and bonding process of the AWG chip 1 and the photoelectric detector 5 are lower.

[0042] For the AWG chip 1 itself, as shown in Figure 4 and Figure 5 The AWG chip 1 further comprises a waveguide layer 11 and a silicon-based substrate 12, the waveguide layer 11 is located between the glass cover plate 2 and the silicon-based substrate 12, and the silicon-based substrate 12 is located on the cushion block 4. The integrated lens 10 is etched on the silicon-based substrate 12.

[0043] In one embodiment, the waveguide layer 11 and the glass cover plate 2 are fixedly connected in a bonded manner, and the waveguide layer 11 and the glass cover plate 2 are polished at a preset angle after being bonded to form a reflection end face 13 and a coupling end face 14.

[0044] The thickness of the silicon substrate 12 is 0.6-0.7mm; the polishing angle of the reflection end face 13 is 40-42 degrees, and the reflection end face 13 is used to reflect the optical signal into the photoelectric detector 5.

[0045] The thickness of the silicon substrate 12 can be 0.6mm, 0.65mm or 0.7mm, and the thickness of the silicon substrate 12 can be any value in the range of 0.6-0.7mm, which can be determined according to actual conditions, and the embodiment is not limited in particular.

[0046] The thickness of the glass cover 2 is 0.1-0.2mm. The thickness of the glass cover 2 can be 0.1mm, 0.15mm or 0.2mm, and the thickness can be any value in the range of 0.1-0.2mm, which can be determined according to actual conditions, and the embodiment is not limited in particular.

[0047] The polishing angle of the reflection end face 13 can be 40 degrees, 41 degrees or 42 degrees, and the polishing angle of the reflection end face 13 can be any value in the range of 40-42 degrees, which can be determined according to actual conditions, and the embodiment is not limited in particular. The coupling end face 14 is one end of the AWG chip 1 and the optical fiber capillary tube 3 in the above-mentioned scheme, and the polishing angle thereof is 7-8 degrees.

[0048] In the prior art, the AWG chip 1 needs to have the waveguide layer 11 facing the light-sensitive surface of the photoelectric detector 5 to achieve near-distance coupling within 30um, and due to the close distance, the surface of the waveguide layer 11 of the AWG chip 1 cannot be protected by the glass cover, and the waveguide layer 11 is prone to breakage during polishing, so there are problems of complex polishing process of the AWG chip 1, easy breakage of the reflection end face, and high requirements for the precision of the coupling equipment and the bonding process. Based on this, the technical scheme provided in the embodiment of the utility model changes the waveguide layer 11 from downward to upward, only needs to polish the area capable of reflecting the optical signal to form the reflection end face 13, and does not need to polish the entire end face of the AWG chip 1, that is, the polishing is stopped after the waveguide layer 11 is polished to the angle, and basically no polishing is needed for the silicon substrate 12. Since the thickness of the glass cover 2 is smaller than the thickness of the silicon substrate 12, the polishing amount is greatly reduced, the waveguide layer 11 is protected by the glass cover 2 arranged above, the polishing process is simple, the waveguide layer 11 is not prone to breakage, and the bonding area of the optical fiber capillary tube 3 and the AWG chip 1 is increased, thereby improving the bonding reliability of the optical fiber capillary tube 3.

[0049] For the AWG chip 1 itself, the AWG chip 1 is formed by wafer processing cutting of a silicon wafer with a size of one of 6 inches or 8 inches. In an actual application scenario, the 6-inch or 8-inch silicon wafer is processed on the surface to form a waveguide pattern as the waveguide layer 11, and the remaining part is a silicon substrate 12. The silicon wafer is reversed, and the integrated lens 10 is etched on the surface of the silicon substrate 12 at an output position. The processed silicon wafer is cut into a bar, and a glass cover 2 is attached for polishing and grinding of the reflection end face 13 and the coupling end face 14. Then, the polished bar is cut into the AWG chip 1.

[0050] When the AWG chip 1 is bonded on the cushion block 4 as a whole, it is necessary to ensure that the optical signal can be transmitted into the photodetector 5 to the maximum extent. Specifically, the AWG chip 1 is attached with the glass cover 2 on the upper side, the optical fiber capillary tube 3 is coupled with the coupling end face 14, the optical signal is input into the waveguide layer 11 of the AWG chip 1 through the optical fiber capillary tube 3, and then is reflected into the silicon substrate 12 through the reflection end face 13. The light is converged through the integrated lens 10, and finally is projected into the light-sensitive surface of the photodetector 5, thereby completing the reception of the optical signal. The AWG chip 1 is moved on the cushion block 4, and when the responsivity of the photodetector 5 is the maximum, the position is the position at which the optical signal can be transmitted into the photodetector 5 to the maximum extent. The bottom surface of the silicon substrate 12 is fixed with the cushion block 4 by using ultraviolet glue.

[0051] The integrated lens 10 scheme provided in the embodiment of the utility model takes the silicon substrate 12 as a part of the integrated lens 10 coupling light path, and does not additionally set the lens 3' and the lens support 4', avoids the bonding alignment problem between the lens 3' and the lens support 4', shortens the distance of the whole light path, reduces the size of the whole assembly, and improves the integration of the optical module.

[0052] Based on the above scheme, the utility model further provides an optical module, as shown in the figure, which comprises a light receiving assembly 7 and a light emitting assembly 8. Figure 6 The light receiving assembly 7 is the light receiving assembly in the above scheme, the light emitting assembly 8 is used for emitting optical signal, and the light receiving assembly 7 is used for receiving return optical signal. As shown in the figure, it is the overall structure schematic diagram of the light receiving assembly 7. Figure 7

[0053] The above only describes the preferred embodiment of the utility model, and does not limit the utility model. Any modification, equivalent replacement and improvement within the spirit and principle of the utility model should be included in the protection scope of the utility model.​

Claims

1. An optical receiving component, characterized in that, It comprises: AWG chip (1), glass cover sheet (2), optical fiber capillary (3), cushion block (4), photodetector (5) and circuit board (6); the glass cover sheet (2) is fixedly arranged on the upper surface of the AWG chip (1), the optical fiber capillary (3) is coupled with one end of the AWG chip (1), the cushion block (4) is fixedly arranged on the lower surface of the AWG chip (1), and the cushion block (4) and the photodetector (5) are fixedly arranged on the circuit board (6); One end of the AWG chip (1) is provided with an integrated lens (10), the integrated lens (10) is arranged on the opposite side of the optical fiber capillary (3), the integrated lens (10) is located above the photodetector (5), and the center of the integrated lens (10) and the center of the photodetector (5) are located on the same straight line.

2. The optical receiving assembly of claim 1, wherein, It comprises: The AWG chip (1) further comprises a waveguide layer (11) and a silicon-based substrate (12), the waveguide layer (11) is located between the glass cover sheet (2) and the silicon-based substrate (12), and the silicon-based substrate (12) is located on the cushion block (4); An integrated lens (10) is etched on the silicon-based substrate (12).

3. The optical receiving assembly of claim 2, wherein, After the waveguide layer (11) and the glass cover sheet (2) are bonded, the two ends of the AWG chip (1) and the glass cover sheet (2) are polished at a preset angle to form a reflection end face (13) and a coupling end face (14).

4. The optical receiving assembly of claim 3, wherein, The polishing angle of the reflection end face (13) is 40-42 degrees, and the reflection end face (13) is used for reflecting the optical signal into the photodetector (5).

5. The optical receiving assembly of claim 2, wherein, The thickness of the silicon-based substrate (12) is 0.6-0.7mm.

6. The optical receiving assembly of claim 2, wherein, The AWG chip (1) is formed by processing and cutting a silicon wafer, and the size of the silicon wafer is one of 6 inches or 8 inches.

7. The optical receiving assembly of any of claims 1-6, wherein, The material of the cushion block (4) is one of ceramic sheet or glass sheet, the difference between the expansion coefficients of the cushion block (4) and the AWG chip (1) is less than a preset value, and the thickness of the cushion block (4) can make the optical signal pass through the integrated lens (10) to form a light spot into the photodetector (5).

8. The optical receiving assembly of any of claims 1-6, wherein, The polishing angle of the end of the AWG chip (1) coupled with the optical fiber capillary (3) is 7-8 degrees.

9. The optical receiving assembly of any of claims 1-6, wherein, The thickness of the glass cover sheet (2) is 0.1-0.2mm.

10. An optical module characterized by comprising: It comprises the optical receiving assembly (7) and the optical transmitting assembly (8) according to any one of claims 1-9, the optical transmitting assembly (8) is used for transmitting optical signal, and the optical receiving assembly (7) is used for receiving return optical signal.

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