A detection device, equipment and method

Abstract

The present application provides a detection device, equipment and method, which belongs to the field of laser technology. The detection device is used to detect vertical cavity surface emitting lasers; the detection device includes an amplifying imaging system, a camera and a moving part connected to the camera; the vertical cavity surface emitting laser to be tested, the amplifying imaging system and the camera are arranged on the same optical axis; the amplifying imaging system is used to amplify the laser beam emitted by the vertical cavity surface emitting laser to be tested; the moving part is used to move the camera; the camera is used to obtain the image of the laser beam amplified by the amplifying imaging system at different positions. In an embodiment of the present application, by obtaining the image of the laser beam at different positions, the minimum spot and the far-field position of the laser beam are obtained, and then the divergence angle of the vertical cavity surface emitting laser and the beam quality of the laser can be accurately obtained.

Description

Technical Field

[0001] The present application relates to the field of technical laser technology, for example, to a detection device, equipment and method. Background Art

[0002] At present, the detection of vertical-cavity surface-emitting laser (VCSEL) relies on the light-emitting diode (LED) test platform. Due to the essential difference between LED testing and laser testing, the divergence characteristics of laser are not simply linear diffusion. Therefore, the LED test platform cannot accurately obtain the divergence angle of the vertical-cavity surface-emitting laser, nor can it test the accuracy of the minimum spot and laser beam quality. Summary of the invention

[0003] In view of this, the purpose of the present application is to provide a detection device, equipment and method to improve the above-mentioned problem of "inability to accurately obtain the divergence angle of the vertical cavity surface emitting laser, and inability to test the accuracy of the minimum spot and the beam quality of the laser".

[0004] In order to solve the above technical problems, the embodiments of the present application are implemented in the following ways:

[0005] In a first aspect, an embodiment of the present application provides a detection device for detecting a vertical cavity surface emitting laser; the detection device includes an amplifying imaging system, a camera, and a movable part connected to the camera; the vertical cavity surface emitting laser to be tested, the amplifying imaging system, and the camera are arranged on a common optical axis; the amplifying imaging system is used to amplify the laser beam emitted by the vertical cavity surface emitting laser to be tested; the movable part is used to move the camera; and the camera is used to obtain an image of the laser beam amplified by the amplifying imaging system at different positions.

[0006] In the embodiment of the present application, by acquiring images of the laser beam at different positions, the minimum spot and the far-field position of the laser beam are obtained, and then the divergence angle of the vertical cavity surface emitting laser and the beam quality of the laser can be accurately obtained. In addition, the magnified imaging system in the embodiment of the present application can make the measurement more accurate and reduce mechanical errors.

[0007] In combination with the technical solution provided in the first aspect above, in some possible implementations, the magnifying imaging system includes a microscope objective and a lens barrel; the microscope objective is arranged at one end of the lens barrel, and the vertical cavity surface emitting laser to be measured is placed on a side of the microscope objective away from the lens barrel.

[0008] In the present application, by providing a microscope objective lens and a lens barrel, the laser beam emitted by the vertical cavity surface emitting laser to be measured can be more accurately amplified, making the measurement more accurate.

[0009] In combination with the technical solution provided in the first aspect above, in some possible implementations, the magnifying imaging system further includes a tube lens; the tube lens is arranged at the other end of the lens barrel, and the tube lens and the microscope objective lens are located at opposite ends of the lens barrel.

[0010] In this application, adding a tube lens can achieve a better focusing effect and further improve the measurement effect.

[0011] In combination with the technical solution provided in the first aspect above, in some possible implementations, the moving part includes a connecting part, a slide rail and a motor; the connecting part is connected to the camera, the connecting part is placed on the slide rail, and the motor is used to drive the connecting part to move along the track of the slide rail to move the camera.

[0012] In the present application, by providing a motor and a slide rail, the camera can be stably moved to the measurement position, thereby reducing mechanical errors during testing.

[0013] In a second aspect, an embodiment of the present application provides a detection device for detecting a vertical cavity surface emitting laser, the detection device comprising: an operating table and a detection device provided in the first aspect as described above and placed on the operating table.

[0014] In combination with the technical solution provided in the second aspect above, in some possible implementations, the detection device further includes a fixing member; the fixing member is placed on the operating table, and the fixing member is used to fix the vertical cavity surface emitting laser to be tested.

[0015] In a third aspect, an embodiment of the present application provides a detection method, which is applied to the detection device provided in the first aspect above; the method includes: turning on the vertical cavity surface emitting laser to be tested; moving the camera to a first position, a second position and a third position, respectively acquiring a first image of the laser emitted by the vertical cavity surface emitting laser to be tested at the first position, a second image at the second position and a third image at the third position; determining a far-field position based on the first image, the second image and the third image; moving the camera to the far-field position to acquire a fourth image; and obtaining a divergence angle and a beam quality of the laser emitted by the vertical cavity surface emitting laser to be tested based on the first image, the second image, the third image and the fourth image.

[0016] In the present application, by moving the camera to three different positions, the first image, the second image and the third image can be acquired. The far-field position can be determined based on the three images. The camera is then moved to the far-field position to acquire the fourth image. Based on the first image, the second image, the third image and the fourth image, the divergence angle and the beam quality of the laser emitted by the vertical cavity surface emitting laser to be tested can be accurately obtained.

[0017] In combination with the technical solution provided in the third aspect above, in some possible implementation methods, determining the far-field position based on the first image, the second image, and the third image includes: fitting the light spot in the first image, the light spot in the second image, and the light spot in the third image through a parabola to obtain the minimum light spot on the image side; obtaining the Rayleigh length based on the minimum light spot on the image side; and determining the far-field position based on the Rayleigh length.

[0018] In combination with the technical solution provided in the third aspect above, in some possible implementations, obtaining the Rayleigh length based on the image-side minimum light spot includes: dividing the image-side minimum light spot by the magnification of the magnifying imaging system to obtain the object-side minimum light spot; and obtaining the Rayleigh length based on the object-side minimum light spot.

[0019] In combination with the technical solution provided in the third aspect above, in some possible implementations, the divergence angle and beam quality of the laser emitted by the vertical cavity surface emitting laser to be tested are obtained according to the first image, the second image, the third image and the fourth image, including: obtaining the image-side minimum spot through parabola fitting according to the spot in the first image, the spot in the second image and the spot in the third image, and then obtaining the vertex position of the image-side minimum spot; obtaining the spot size at the far-field position according to the fourth image; obtaining the divergence angle and beam quality of the laser emitted by the vertical cavity surface emitting laser to be tested according to the vertex position of the image-side minimum spot, the image-side minimum spot, the far-field position and the spot size at the far-field position.

[0020] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or understood by implementing the embodiments of the present application. The purpose and other advantages of the present application can be realized and obtained by the structures specifically pointed out in the written description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A schematic diagram of the structure of a detection device provided in an embodiment of the present application.

[0023] Figure 2 A schematic structural diagram of a camera and a moving part provided in an embodiment of the present application.

[0024] Figure 3 A schematic diagram of the structure of a detection device provided in an embodiment of the present application.

[0025] Figure 4 A flow chart of a detection method provided in an embodiment of the present application.

[0026] Figure 5 A flowchart of a method for obtaining step S103 provided in an embodiment of the present application.

[0027] Figure 6 A flowchart of a method for obtaining step S105 provided in an embodiment of the present application.

[0028] Icons: 100-detection device; 10-magnification imaging system; 11-microscope objective lens; 12-lens barrel; 13-tube lens; 20-camera; 30-moving part; 31-connecting part; 32-slide rail; 33-motor; 200-vertical cavity surface emitting laser to be tested; 300-detection equipment; 40-operating table; 50-fixed part. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0030] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0031] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0032] In the description of the embodiments of the present application, in addition, the terms "first", "second", "third", "fourth", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0033] In the prior art, the detection of vertical cavity surface emitting lasers relies on LED test platforms. Since LED testing is essentially different from laser testing, the divergence characteristics of lasers are not simply linear diffusion. Therefore, the LED test platform cannot accurately obtain the divergence angle of the vertical cavity surface emitting laser, nor can it test the accuracy of the minimum spot and laser beam quality.

[0034] In view of the above problems, the inventors of the present application have proposed the following embodiments to solve the above problems after research and exploration.

[0035] Please refer to Figure 1 The embodiment of the present application provides a detection device 100, which is used to detect a vertical cavity surface emitting laser. Specifically, the detection device 100 is used to detect the minimum spot, divergence angle and beam quality of the vertical cavity surface emitting laser.

[0036] The detection device 100 includes: a magnifying imaging system 10 , a camera 20 and a moving part 30 .

[0037] The magnifying imaging system 10 is placed between the VCSEL 200 to be tested and the camera 20 , and the VCSEL 20 to be tested, the magnifying imaging system 10 and the camera 20 are arranged on a common optical axis.

[0038] The amplifying imaging system 10 is used to amplify the laser beam emitted by the vertical cavity surface emitting laser 200 to be tested.

[0039] Optionally, the magnifying imaging system 10 includes a microscope objective lens 11 and a lens barrel 12. The microscope objective lens 11 is arranged at one end of the lens barrel 12. The vertical cavity surface emitting laser 200 to be measured is placed on the side of the microscope objective lens 11 away from the lens barrel 121. In the present embodiment, the microscope objective lens 11 with a magnification of 10 times is selected. It can be understood that in different scenes, the magnification of the selected microscope objective lens 11 is different. For example, a microscope objective lens 11 with a magnification of 50 times can also be selected in other scenes, and this application is not limited to this. In the embodiment of the present application, by arranging the microscope objective lens 11 and the lens barrel 12, the laser beam emitted by the vertical cavity surface emitting laser 200 to be measured can be more accurately amplified, so that the measurement is more accurate.

[0040] As another implementation, the magnifying imaging system 10 may also be other devices, such as a magnifying glass, which is not limited in the present application.

[0041] Optionally, the magnifying imaging system 10 further includes a tube lens 13. The tube lens 13 is disposed at the other end of the lens barrel 12, so that the tube lens 13 and the microscope objective lens 11 are located at opposite ends of the lens barrel 12. In the embodiment of the present application, the addition of the tube lens 13 can achieve a better focusing effect and further improve the measurement effect.

[0042] The moving member 30 is connected to the camera 20, and is used to move the camera 20. The moving member 30 can move the camera so that the camera 20 can image the laser beam magnified by the magnifying imaging system 10 at different positions.

[0043] See also Figure 2 As an embodiment, the moving member 30 includes a connecting member 31, a slide rail 32 and a motor 33. The connecting member 31 is connected to the camera 20. The connecting member 31 is placed on the slide rail 32 and can slide on the slide rail 32. The motor 33 is used to drive the connecting member 31 to move along the track of the slide rail 32 to move the camera 20. The camera 20 is used to obtain an image of the laser beam magnified by the magnifying imaging system 10 at different positions. In the embodiment of the present application, by setting the motor 33 and the slide rail 32, the camera 20 can be stably moved to the measurement position, thereby reducing the mechanical error during the test.

[0044] As another embodiment, the moving member includes a connecting member, a slide groove and a motor. The connecting member is connected to the camera. The connecting member is placed inside the slide groove and can slide inside the slide groove. The motor is used to drive the connecting member to move along the slide groove to move the camera. The camera is used to obtain images of the laser beam magnified by the magnifying imaging system at different positions.

[0045] In the embodiment of the present application, by acquiring images of the laser beam at different positions, the minimum spot and the far-field position of the laser beam are obtained, and then the divergence angle of the vertical cavity surface emitting laser and the beam quality of the laser can be accurately obtained. In addition, the magnified imaging system 10 in the embodiment of the present application can make the measurement more accurate and reduce mechanical errors.

[0046] See also Figure 3 The embodiment of the present application further provides a detection device 300. The detection device 300 is used to detect a vertical cavity surface emitting laser, and specifically, is used to detect the minimum spot, divergence angle and beam quality of the vertical cavity surface emitting laser.

[0047] The detection equipment 300 includes an operating table 40 and the above-mentioned detection device 100 placed on the operating table 40 .

[0048] Optionally, the detection device 300 further includes a fixing member 50. The fixing member 50 is placed on the operating table 40 and is used to fix the vertical cavity surface emitting laser 200 to be tested.

[0049] Optionally, the fixing member 50 may also be used to fix the magnifying imaging system 10 .

[0050] See also Figure 4 The embodiment of the present application further provides a detection method, which is applied to the above detection device 100. The method includes: steps S101-S105.

[0051] Step S101: Turn on the vertical cavity surface emitting laser 200 to be tested.

[0052] Before measuring, first, the VCSEL 200 to be measured is placed in the measuring position so that the VCSEL 200 to be measured is coaxially arranged with the magnifying imaging system 10 and the camera 20 in the detection device 100. Then, the VCSEL 200 to be measured is turned on.

[0053] Step S102: Move the camera 20 to a first position, a second position and a third position to respectively acquire a first image of the laser emitted by the vertical cavity surface emitting laser to be tested at the first position, a second image at the second position and a third image at the third position.

[0054] Specifically, first, turn on the camera 20 in the detection device and move the camera to the first position. It should be noted that the first position can be a position of one Rayleigh length. It is understandable that those skilled in the art should be clear about the numerical range of the Rayleigh length for vertical cavity surface emitting lasers of different specifications and models. Therefore, the first position of one Rayleigh length to which the camera 20 moves is an approximate position calculated based on the experience of the staff. When the camera 20 moves to the first position, a first image of the laser emitted by the vertical cavity surface emitting laser 200 to be tested at the first position is obtained. Afterwards, the camera 20 is moved to the second position to obtain a second image of the laser emitted by the vertical cavity surface emitting laser 200 to be tested at the second position. The distance between the second position and the first position can be one Rayleigh length. Then, the camera 20 is moved to the third position to obtain a third image of the laser emitted by the vertical cavity surface emitting laser 200 to be tested at the third position. The distance between the third position and the second position can also be one Rayleigh length.

[0055] It is understood that in other embodiments, the first position may also be 1.5 times the Rayleigh length position or 0.5 times the Rayleigh length position. The distance between the first position and the second position and / or the distance between the second position and the third position may also be 1.2 times the Rayleigh length position. This application does not limit this.

[0056] Step S103: determining the far field position according to the first image, the second image and the third image.

[0057] See also Figure 4 Specifically, determining the far-field position according to the first image, the second image, and the third image may include: steps S201-S203.

[0058] Step S201: fitting the light spot in the first image, the light spot in the second image, and the light spot in the third image through a parabola to obtain the minimum light spot on the image side.

[0059] Step S202: Calculate the Rayleigh length based on the minimum light spot on the image side.

[0060] In order to obtain the Rayleigh length based on the minimum spot on the image side, the minimum spot on the image side must first be divided by the magnification of the magnifying imaging system 10 to obtain the minimum spot on the object side. If the magnification of the magnifying imaging system 10 is 10 times, the minimum spot on the image side must be divided by the magnification of 10 times to obtain the minimum spot on the object side; if the magnification of the magnifying imaging system 10 is 20 times, the minimum spot on the image side must be divided by the magnification of 20 times to obtain the minimum spot on the object side. After obtaining the minimum spot on the object side, the Rayleigh length is obtained based on the minimum spot on the object side. The formula for calculating the Rayleigh length is: Where Z r represents the Rayleigh length, ω 0 represents the object-side minimum spot, and λ represents the wavelength. Since π and wavelength λ are both known values, the object-side minimum spot ω is obtained. 0 The Rayleigh length Z can be obtained r .

[0061] Step S203: Determine the far field position according to the Rayleigh length.

[0062] After obtaining the accurate Rayleigh length, the accurate far-field position can be obtained according to the Rayleigh length. In the embodiment of the present application, the far-field position can be, for example, a position of 4 times the Rayleigh length.

[0063] Step S104: Move the camera 20 to the far-field position to acquire a fourth image.

[0064] After the accurate far-field position is acquired, the camera 20 is moved to the far-field position to acquire a fourth image of the laser light emitted by the vertical cavity surface emitting laser 200 to be tested at the far-field position.

[0065] Step S105: Obtain the divergence angle and beam quality of the laser light emitted by the vertical cavity surface emitting laser 200 to be tested according to the first image, the second image, the third image and the fourth image.

[0066] Specifically, obtaining the divergence angle and beam quality of the laser emitted by the vertical cavity surface emitting laser to be tested according to the first image, the second image, the third image and the fourth image may include: steps S301-S303.

[0067] Step S301: obtaining the minimum light spot on the image side through parabola fitting according to the light spot in the first image, the light spot in the second image and the light spot in the third image, and then obtaining the vertex position of the minimum light spot on the image side.

[0068] After obtaining the first image, the second image, and the third image of the laser emitted by the vertical cavity surface emitting laser 200 to be tested, the minimum spot on the image side is obtained by parabola fitting based on the spot in the first image, the spot in the second image, and the spot in the third image, and then the vertex position of the minimum spot on the image side is obtained.

[0069] Step S302: Obtain the spot size at the far-field position according to the fourth image.

[0070] Step S303: Obtain the divergence angle and beam quality of the laser emitted by the vertical cavity surface emitting laser 200 to be tested according to the vertex position of the image-side minimum spot, the image-side minimum spot, the far-field position, and the spot size at the far-field position. The formula for calculating the divergence angle of the vertical cavity surface emitting laser 200 to be tested is: Where NA represents the divergence angle of the vertical cavity surface emitting laser 200 to be tested, ω zff represents the spot size at the far field position, ω 0 represents the minimum spot size on the object side, zff represents the far field position, and Z 0 represents the vertex position of the minimum light spot on the image side; wherein the beam quality of the vertical cavity surface emitting laser 200 to be tested is calculated Among them, M 2 Indicates the beam quality of the vertical cavity surface emitting laser 200 to be tested.

[0071] In the embodiment of the present application, by moving the camera 20 to three different positions, a first image, a second image and a third image can be acquired, and the far-field position can be determined based on the three images. Then, the camera 20 is moved to the far-field position to acquire a fourth image, and based on the first image, the second image, the third image and the fourth image, the divergence angle and the beam quality of the laser emitted by the vertical cavity surface emitting laser 200 to be tested can be accurately obtained.

[0072] It is understandable that the detection device provided in the embodiment of the present application also includes a processor and a memory, and the processor can be set integrally with the detection device 100, that is, the processor is placed inside the detection device 100, or it can be a control cabinet set separately, or it can be a remote server, which is not limited here. The processor is used to execute the program stored in the memory, for example, the processor is used to drive the motor 33 so that the motor 33 moves the camera 20 to the first position, the second position and the third position in sequence. The processor is also used to obtain the first image of the laser emitted by the vertical cavity surface emitting laser 200 to be tested at the first position, the second image at the second position, and the third image at the third position, and determine the far field position according to the first image, the second image and the third image. The processor is also used to drive the motor 33 to move the camera 20 to the far field position and obtain a fourth image. The processor is also used to obtain the divergence angle and beam quality of the laser emitted by the vertical cavity surface emitting laser 200 to be tested according to the first image, the second image, the third image and the fourth image.

[0073] The memory may be a high-speed RAM memory or a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0074] The processor may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present application may be implemented or executed. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0075] In the embodiments provided by the present invention, it should be understood that the disclosed methods, devices, and electronic devices may also be implemented in other ways. The embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architectures, functions, and operations of the methods, devices, and electronic device products according to multiple embodiments of the present invention. It should also be noted that in some alternative implementations, the functions marked in the boxes may also occur in an order different from that marked in the accompanying drawings.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A detection method for detecting a vertical cavity surface emitting laser, characterized in that: A detection device for detecting a vertical cavity surface emitting laser, the detection device comprising: an amplifying imaging system, a camera and a moving part connected to the camera; the vertical cavity surface emitting laser to be tested, the amplifying imaging system and the camera are arranged on a common optical axis; the amplifying imaging system is used to amplify the laser beam emitted by the vertical cavity surface emitting laser to be tested; the moving part is used to move the camera; the camera is used to obtain an image of the laser beam amplified by the amplifying imaging system at different positions; the method comprises: Turning on the vertical cavity surface emitting laser to be tested; Move the camera to a first position, a second position, and a third position, and respectively acquire a first image of the laser emitted by the vertical cavity surface emitting laser to be tested at the first position, a second image at the second position, and a third image at the third position; determining a far-field position according to the first image, the second image, and the third image; Moving the camera to the far-field position to acquire a fourth image; Obtaining the divergence angle and beam quality of the laser emitted by the vertical cavity surface emitting laser to be tested according to the first image, the second image, the third image and the fourth image; The step of obtaining the divergence angle and beam quality of the laser emitted by the vertical cavity surface emitting laser to be tested according to the first image, the second image, the third image and the fourth image comprises: obtaining the image-side minimum spot through parabola fitting according to the spot in the first image, the spot in the second image and the spot in the third image, and then obtaining the vertex position of the image-side minimum spot; obtaining the spot size at the far-field position according to the fourth image; obtaining the divergence angle and beam quality of the laser emitted by the vertical cavity surface emitting laser to be tested according to the vertex position of the image-side minimum spot, the image-side minimum spot, the far-field position and the spot size at the far-field position; The minimum light spot on the object side is obtained by dividing the minimum light spot on the image side by the magnification of the magnifying imaging system; Among them, the formula for calculating the divergence angle of the vertical cavity surface emitting laser to be tested is: Wherein, NA represents the divergence angle of the vertical cavity surface emitting laser to be measured, represents the spot size at the far field position, represents the minimum spot size on the object side, zff represents the far field position, Indicates the vertex position of the minimum light spot on the image side.

2. The detection method according to claim 1, characterized in that: The determining of the far-field position according to the first image, the second image, and the third image includes: Fitting the light spot in the first image, the light spot in the second image, and the light spot in the third image through a parabola to obtain the minimum light spot on the image side; The Rayleigh length is obtained according to the minimum spot size on the image side; The far field position is determined based on the Rayleigh length.

3. The detection method according to claim 2, characterized in that: The step of obtaining the Rayleigh length according to the image-side minimum light spot comprises: The Rayleigh length is obtained according to the object-side minimum light spot.

4. The detection method according to claim 1, characterized in that: The magnifying imaging system comprises a microscope objective lens and a lens barrel; the microscope objective lens is arranged at one end of the lens barrel, and the vertical cavity surface emitting laser to be measured is placed on a side of the microscope objective lens away from the lens barrel.

5. The detection method according to claim 4, characterized in that: The magnifying imaging system further comprises a tube lens; the tube lens is arranged at the other end of the lens barrel, and the tube lens and the microscope objective lens are located at opposite ends of the lens barrel.

6. The detection method according to claim 1, characterized in that: The moving part includes a connecting part, a slide rail and a motor; the connecting part is connected to the camera, the connecting part is placed on the slide rail, and the motor is used to drive the connecting part to move along the track of the slide rail to move the camera.

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