Air-to-air optical module and its fast alignment method

Abstract

The application relates to the technical field of optical communication, and provides an air-to-air optical module, which comprises a light receiving assembly and a light emitting assembly, the light receiving assembly and the light emitting assembly are arranged in an up-down interval mode, and the light emitting assembly is provided with a wedge angle piece assembly used for adjusting the direction of an optical axis. A rapid alignment method of the air-to-air optical module is also provided. Through the up-down interval arrangement of the light receiving assembly and the light emitting assembly and the adjusting function of the wedge angle piece assembly, low-precision mechanical butt joint can be realized, optical signal coupling is achieved between devices, optical fiber butt joint is not needed, and high-efficiency and convenient high-speed and multi-channel one-way data transmission can be realized through manual low-precision alignment.

Description

Technical Field

[0001] This invention relates to the field of optical communication technology, specifically to an air-to-air optical transmission module and its rapid alignment method. Background Technology

[0002] Currently, optical module transmission mainly uses fiber optic patch cords to transmit optical signals. This method offers long transmission distances and high signal rates, primarily targeting transmissions where the distance between the transmitting and receiving modules is relatively large. However, in some signal transmission scenarios, a long distance is not required, with transmission distances as small as 3-7mm. Using fiber optic connections would take up space and be inconvenient. In such cases, wireless air-to-air transmission can be used. This type of signal transmission requires small package sizes for both transmitting and receiving modules, easy installation (low alignment accuracy), large optical alignment tolerance, and high speed. However, the alignment tolerance of traditional high-speed transmission optical modules is only at the tens of micrometer level. This small tolerance cannot meet the requirements of low-precision installation. The higher the transmission rate, the larger the photosensitive surface of the PD, and the higher the requirements for optical path alignment. Summary of the Invention

[0003] The purpose of this invention is to provide an air-to-light transmission module and a rapid alignment method thereof, which can at least solve some of the defects in the prior art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an air-to-light transmission module, comprising a light receiving component and a light emitting component, wherein the light receiving component and the light emitting component are arranged vertically at intervals, and the light emitting component has a wedge plate component for adjusting the direction of the optical axis.

[0005] Furthermore, the wedge plate assembly includes a first wedge plate for adjusting the angle of the optical axis in the X direction and a second wedge plate for adjusting the angle of the optical axis in the Y direction, wherein the first wedge plate and the second wedge plate are spaced apart along the optical path direction.

[0006] Furthermore, at least one of the first wedge plate and the second wedge plate is provided with a fine-tuning mechanism for the optical axis direction.

[0007] Furthermore, the optical axis fine-tuning mechanism includes a positive electrode film, a plasma film, and a negative electrode film that are sequentially bonded together. The combined film formed by the positive electrode film, the plasma film, and the negative electrode film is disposed on the emission surface of the wedge plate assembly. The positive electrode film and the negative electrode film are connected to a voltage controller.

[0008] Furthermore, both the positive electrode film and the negative electrode film are transparent films.

[0009] Furthermore, the diameters of the positive electrode film, the plasma film, and the negative electrode film are all in the range of 0.3~0.5 mm.

[0010] Furthermore, the optical emitting component also includes an LD and a large-area PD chip. The first optical signal emitted by the LD chip is emitted to the optical receiving component after the optical axis is adjusted by the wedge plate assembly. The optical receiving component receives the first optical signal emitted by the LD chip and converts it into an electrical signal. The electrical signal drives the VCSEL chip of the optical receiving component to emit a second optical signal. The large-area PD chip receives the second optical signal, thus completing the alignment of the optical emitting component and the optical receiving component.

[0011] Furthermore, the diameter of the photosensitive surface of the large-area PD chip is in the range of 1.3~1.7mm.

[0012] Furthermore, both the light emitting component and the receiving component are encapsulated on the PCBA board via a protective enclosure.

[0013] This invention provides another technical solution: a rapid alignment method for an air-to-light transmission module, comprising the following steps:

[0014] S1, the optical receiving component and the optical transmitting component are set at an upper and lower interval;

[0015] S2, the direction of the optical axis of the first optical signal emitted by the optical emitting component is adjusted by using a wedge plate assembly;

[0016] S3, the first optical signal is reflected by the reflecting prism to the upper optical receiving component;

[0017] S4, after receiving the first optical signal, the optical receiving component converts the first optical signal into an electrical signal, and the electrical signal drives the VCSEL of the optical receiving component to emit a second optical signal, and emits the second optical signal to the optical emitting component;

[0018] S5, if the large-area PD of the light emitting component receives the second light signal, the alignment is completed; if the large-area PD of the light emitting component does not receive the second light signal, the optical axis direction of the first light signal is adjusted by the wedge plate assembly until the large-area PD receives the second light signal.

[0019] Compared with the prior art, the beneficial effects of the present invention are: by setting the upper and lower intervals of the optical receiving component and the optical transmitting component and the adjustment function of the wedge plate component, low-precision mechanical docking can be achieved. Between devices, through optical signal coupling, there is no need for optical fiber docking. Only manual low-precision alignment is required to efficiently and conveniently achieve high-speed, multi-channel unidirectional data transmission. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the exploded structure of the light emitting component of an air-to-light transmission module provided in an embodiment of the present invention;

[0021] Figure 2 This is an exploded structural diagram of the optical receiving component of an air-to-light transmission module provided in an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the positional relationship and matching structure of the light emitting component and the light receiving component of an air-to-light transmission module provided in an embodiment of the present invention (some components are omitted and the diagram is in perspective).

[0023] Figure 4 A side view structural diagram of a wedge plate of an air-to-light transmission module provided in an embodiment of the present invention;

[0024] Figure 5 This is a disassembly diagram of a combined membrane for a fine-tuning mechanism of the optical axis direction of an air-to-light transmission module, provided in an embodiment of the present invention.

[0025] In the attached figures, the following labels are used: 10-light receiving component; 100-first wedge plate; 101-second wedge plate; 102-positive electrode film; 103-plasma film; 104-negative electrode film; 105-reflecting prism; 106-driver chip; 107-LD chip; 108-LD lens; 109-voltage controller; 110-large area PD chip; 111-protective cover; 112-glass cover; 113-PCBA board; 114-emission surface. 115 - Composite film; 116 - Upper surface; 117 - Lower surface; 118 - Pad for positive electrode film; 119 - Pad for negative electrode film; 20 - Light emitting component; 200 - TIA chip and VCSEL chip; 201 - VCSEL lens; 202 - VCSEL lens pad; 203 - PD chip; 204 - PD lens; 205 - PD lens pad; 206 - Protective cover; 207 - Glass cover; 208 - PCBA board. Detailed Implementation

[0026] 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Please see Figure 1 , Figure 2 and Figure 3This invention provides an air-to-air optical transmission module, including an optical receiving component 10 and an optical transmitting component 20. The optical receiving component 10 and the optical transmitting component 20 are arranged vertically at a distance, and the optical transmitting component 20 has a wedge-shaped plate assembly for adjusting the optical axis direction. This invention proposes an optical device data transmission component with a small package size and large alignment tolerance. Through the vertical spacing of the optical receiving component 10 and the optical transmitting component 20 and the adjustment function of the wedge-shaped plate assembly, low-precision mechanical docking can be achieved. Between devices, optical signal coupling is achieved without fiber optic docking; only manual low-precision alignment is required to efficiently and conveniently achieve high-speed, multi-channel unidirectional data transmission. Preferably, the optical receiving component 10 and the optical transmitting component 20 are spaced 3-5 mm apart. After alignment, the optical receiving component 10 and the optical transmitting component 20 can be placed in a housing for use. During use, if inaccurate alignment is found, the optical receiving component 10 and the optical transmitting component 20 can be quickly aligned using the wedge-shaped plate assembly. After alignment, the current adjustment state of the wedge-shaped plate assembly is fixed to complete high-speed signal transmission.

[0028] Please see Figure 1 , Figure 2 and Figure 3 The wedge plate assembly includes a first wedge plate 100 for adjusting the angle in the X-axis direction and a second wedge plate 101 for adjusting the angle in the Y-axis direction. The first wedge plate 100 and the second wedge plate 101 are spaced apart along the optical path direction. In this embodiment, the first wedge plate 100 and the second wedge plate 101 can be used to adjust the X-axis direction and the Y-axis direction, respectively. When there are multiple optical paths, multiple sets of wedge plates can be used. For example, this embodiment shows two optical paths, so each optical path is provided with a first wedge plate 100 and a second wedge plate 101. In addition, the adjustment of the optical axis direction can be divided into two steps. The first step is the mounting of the first wedge plate 100 and the second wedge plate 101. After the positions of the first wedge plate 100 and the second wedge plate 101 are aligned and adjusted, the initial mounting of the first wedge plate 100 and the second wedge plate 101 is completed. The second adjustment is achieved through a fine-tuning mechanism in the optical axis direction. When inaccurate alignment occurs during later use, this mechanism is used for fine-tuning. Therefore, combining the above adjustments, the two-step adjustment can be divided into coarse adjustment and fine adjustment.

[0029] For further optimization of the above solution, please refer to [link / reference]. Figure 1 , Figure 2 and Figure 3At least one of the first wedge plate 100 and the second wedge plate 101 is provided with a fine-tuning mechanism for the optical axis direction. In this embodiment, the fine-tuning mechanism for the optical axis direction can be provided on both wedge plates or only on one of them, which can be selected according to the adjustment needs. The fine-tuning mechanism for the optical axis direction includes a positive electrode film 102, a plasma film 103, and a negative electrode film 104 sequentially bonded together. A combined film 115 formed by the positive electrode film 102, the plasma film 103, and the negative electrode film 104 is disposed on the emission surface 114 of the wedge plate assembly. The positive electrode film 102 and the negative electrode film 104 are connected to a voltage controller 109. (See also...) Figure 4 and Figure 5 The combined film 115 is disposed on the exit surface 114 of the wedge plate. Utilizing the Pockels effect, when an external voltage is applied to the plasma, it will cause changes in the dielectric constant and magnetic permeability of the material, thereby leading to dynamic adjustment of the refractive index. That is, by connecting the positive electrode film 102 and the negative electrode film 104 through the voltage controller 109 and providing different voltages, the internal structure and refractive index of the plasma film 103 between the positive electrode film 102 and the negative electrode film 104 can be adjusted to achieve the purpose of adjusting the collimated light spot exiting the optical axis of the LD chip 107. When designing the composite film 115, both the positive electrode film 102 and the negative electrode film 104 can extend to form pads. The pad 118 of the positive electrode film can extend along the emission surface 114 of the wedge plate to the upper surface 116 of the wedge plate, and the pad 119 of the negative electrode film can extend along the emission surface 114 of the wedge plate to the lower surface 117 of the wedge plate. This avoids connection between the emission surface 114 of the wedge plate and the voltage controller 109, thus preventing interference with light emission. Both the positive electrode film 102 and the negative electrode film 104 are transparent films, which improves light transmittance. The diameters of the positive electrode film 102, the plasma film 103, and the negative electrode film 104 are all in the range of 0.3~0.5mm, contributing to the miniaturization of the optical module. Preferably, the aperture diameters of the positive electrode film 102 and the negative electrode film 104 are both in the range of 0.3~0.5mm, and the wedge angle of the wedge plate can be set to 0.5~2°. When the light emitting component 20 and the light receiving component 10 are aligned, there will be a planar alignment tolerance of ±0.5mm and an angular tolerance of ±2°. However, the photosensitive surface of the PD chip for 25G high-speed data transmission is only 40um. Ordinary lenses cannot achieve such a large tolerance range in a small space. Therefore, this application cleverly achieves the purpose of compensating for the assembly angular tolerance by adjusting the output optical axis angle of the wedge plate. The first wedge plate 100 and the second wedge plate 101 can adjust the X and Y direction angles respectively to achieve optimal coupling. The adjustment speed and adjustment logic are programmable into the control chip. When the large-area PD chip 110 receives the optical signal from the VCSEL chip, the adjustment is completed. The controller only needs to stabilize the current voltage during data transmission.

[0030] Please see Figure 1 , Figure 2 and Figure 3The light emitting component 20 also includes an LD and a large-area PD chip 110. The first light signal emitted by the LD chip 107 is emitted to the light receiving component 10 after the optical axis is adjusted by the wedge plate assembly. The light receiving component 10 receives the first light signal emitted by the LD chip 107 and converts it into an electrical signal. The electrical signal drives the VCSEL chip of the light receiving component 10 to emit a second light signal. The large-area PD chip 110 receives the second light signal, thus completing the alignment of the light emitting component 20 and the light receiving component 10. In this embodiment, the light emitting component 20 includes a first wedge plate 100, a second wedge plate 101, a positive electrode film 102, a plasma film 103, a negative electrode film 104, a reflective prism 105, a driver chip 106, an LD chip 107, an LD lens 108, a voltage controller 109, a large-area PD chip 110, a protective cover 111, a glass cover 112, and a PCBA board 113. The light receiving component 10 includes a TIA chip and a VCSEL chip 200, a VCSEL lens 201, a VCSEL lens pad 202, a PD chip 203, a PD lens 204, a PD lens pad 205, a protective cover 206, a glass cover 207, and a PCBA board 208. The driver chip 106 emits a set of signals, which are converted into light signals by the LD chip 107. The light passes through the LD lens 108, the first wedge plate 100, the second wedge plate 101, and the reflecting prism 105, and is directed from the lower light emitting component 20 to the upper light receiving component 10. The light then passes through the glass cover 112 and is emitted. The first light signal passes through the PD lens 204 and is focused onto the PD chip 203, which converts the light signal into an electrical signal and transmits it to the TIA chip. After the TIA chip receives the photocurrent signal generated by the PD chip 203, the VCSEL chip of the light receiving component 10 emits light, which is transmitted to the large-area PD chip 110 of the light emitting component 20 via the VCSEL lens 201. The large-area PD chip 110 senses the signal, indicating that the alignment is complete and high-speed data transmission begins. Preferably, the VCSEL light source in the optical receiving component 10 is a common low-speed light source, which only serves to emit the signal indicating completion of optical docking and does not need to perform high-speed data transmission. The VCSEL chip only emits light when the TIA chip in the optical receiving component 10 detects a responsivity signal of ≥0.7A / W; otherwise, it does not emit light. The large-area PD chip 110 in the optical emitting component 20 has a photosensitive surface diameter in the range of 1.3~1.7mm, and its tolerance for receiving optical signals is much larger than the assembly tolerance of the optical emitting component 20 and the optical receiving component 10. Both the optical emitting component 20 and the receiving component are encapsulated on the PCBA board by a protective enclosure, which can be composed of a protective cover and a glass cover, through which light is emitted.Preferably, the transmission rates of the LD chip 107 and the driver chip 106, and the transmission rates of the PD chip 203 and the TIA chip can all reach 25Gbp / s per channel. The photosensitive surface of the PD chip 203 is ≥40um, and the LD chip 107 is a DFB with a fixed polarization state. In this way, the plasma thin film 103 on the wedge plate can effectively adjust the exit angle of the beam. After the beam is adjusted and aligned, the VCSEL chip on the light receiving component 10 is lit up. After reaching the large-area PD chip 110, the adjustment and alignment are completed.

[0031] The following are the specific assembly steps for the above components:

[0032] The optical emitting component 20 is assembled as follows:

[0033] 1. DB&WB: Passively mount the driver chip 106, LD chip 107, first wedge plate 100, second wedge plate 101, voltage controller 109, large area PD chip 110, and reflective prism 105 onto the PCBA board 113 and perform gold wire bonding.

[0034] 2. Coupling: [The wedge plate controller ensures that the voltage of the plasma thin film 103 on the wedge plate is a fixed value] A special fixture is used to power the PCBA board 113 to make the LD chip 107 emit light. Combined with the standard light receiving component 10, various lenses and LD lenses 108 are actively coupled and fixed to achieve optical path alignment.

[0035] 3. Sealing: The COB optical components are encapsulated with a protective cover to protect the gold wires and optical path.

[0036] The optical receiver component 10 is assembled as follows:

[0037] 1. DB&WB: Passively mount the TIA chip, VCSEL chip 200, PD chip 203, PD lens pad 205, and VCSEL lens pad 202 onto the PCBA board 208 and perform gold wire bonding.

[0038] 2. Lens attachment: Passively attach the VCSEL lens 201 above the VCSEL chip and allow it to cure.

[0039] 3. Couple the lens array. During coupling, use the standard 20 light-emitting component to couple the RX lens array.

[0040] 4. Sealing: The COB optical components are sealed with a protective cover to protect the gold wires and optical path.

[0041] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An air-to-light transmission module, characterized in that: The system includes a light receiving component and a light emitting component, which are arranged vertically at intervals. The light emitting component has a wedge assembly for adjusting the optical axis direction. The wedge assembly includes a first wedge for adjusting the angle in the X-axis direction and a second wedge for adjusting the angle in the Y-axis direction. The first and second wedges are spaced apart along the optical path. At least one of the first and second wedges has an optical axis fine-tuning mechanism. The optical axis fine-tuning mechanism includes a positive electrode film, a plasma film, and a negative electrode film sequentially bonded together. The combined film formed by the negative electrode film is disposed on the emission surface of the wedge plate assembly. The positive electrode film and the negative electrode film are connected to a voltage controller. The light emitting assembly includes a first wedge plate, a second wedge plate, a positive electrode film, a plasma film, a negative electrode film, a reflective prism, a driving chip, an LD chip, an LD lens, a voltage controller, a large-area PD chip, a protective cover, a glass cover, and a PCBA board. The light receiving assembly includes a TIA chip and a VCSEL chip, a VCSEL lens, a VCSEL lens pad, a PD chip, a PD lens, a PD lens pad, a protective cover, a glass cover, and a PCBA board.

2. The air-to-light transmission module as described in claim 1, characterized in that: Both the positive electrode film and the negative electrode film are transparent films.

3. The air-to-light transmission module as described in claim 1, characterized in that: The diameters of the positive electrode film, the plasma film, and the negative electrode film are all in the range of 0.3~0.5 mm.

4. The air-to-light transmission module as described in claim 1, characterized in that: The optical emitting component also includes an LD and a large-area PD chip. The first optical signal emitted by the LD chip is emitted to the optical receiving component after the optical axis is adjusted by the wedge plate component. The optical receiving component receives the first optical signal emitted by the LD chip and converts it into an electrical signal. The electrical signal drives the VCSEL chip of the optical receiving component to emit a second optical signal. The large-area PD chip receives the second optical signal, thus completing the alignment of the optical emitting component and the optical receiving component.

5. The air-to-light transmission module as described in claim 4, characterized in that: The diameter of the photosensitive surface of the large-area PD chip is in the range of 1.3~1.7mm.

6. The air-to-light transmission module as described in claim 1, characterized in that: Both the light emitting component and the receiving component are encapsulated on the PCBA board through a protective enclosure.

7. A rapid alignment method for an air-to-light transmission module, characterized in that, The air-to-light transmission module as described in any one of claims 1-6 includes the following steps: S1, the optical receiving component and the optical transmitting component are set at an upper and lower interval; S2, the direction of the optical axis of the first optical signal emitted by the optical emitting component is adjusted by using a wedge plate assembly; S3, the first optical signal is reflected by the reflecting prism to the upper optical receiving component; S4, after receiving the first optical signal, the optical receiving component converts the first optical signal into an electrical signal, and the electrical signal drives the VCSEL of the optical receiving component to emit a second optical signal, and emits the second optical signal to the optical emitting component; S5, if the large-area PD of the light emitting component receives the second light signal, the alignment is completed; if the large-area PD of the light emitting component does not receive the second light signal, the optical axis direction of the first light signal is adjusted by the wedge plate assembly until the large-area PD receives the second light signal.

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