Light beam coaxiality detection device and detection method

Abstract

The invention relates to a light beam coaxiality detection device and a detection method. The detection device comprises a light splitting focusing device 1 and an optical imaging device 2, wherein the optical imaging device 2 is positioned on a focal plane of the light splitting focusing device 1. At least two transmission areas are arranged on the light splitting focusing device 1, and the wavelengths of light beams which can be transmitted by the transmission areas are different. The same number of imaging areas are arranged on the optical imaging device 2 in a scattered mode, and each imaging area can receive a set of light beams to be imaged in the imaging area. The light beams with different wavelengths split by the light splitting and focusing device 1 form light spots on the optical imaging device 2, and the light beam directions and divergence angles of light with different wavelengths can be determined by observing the central positions and sizes of the light spots and comparing the light spots with standard light spots. The circuit has the advantages of being simple in structure, small in number of components, small in occupied space, stable, reliable, capable of being miniaturized and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of optical detection, and in particular to a light beam coaxiality detection device and detection method. Background Art

[0002] In a spectral-based beam synthesis device, it is usually necessary to detect the coaxiality of each beam in a multi-wavelength mixed beam. Existing detection devices generally use spectroscopic devices such as dichroic mirrors to first separate beams of different wavelengths, then use the detection optical path to detect the optical axis direction of each beam, and finally compare the optical axis directions of each beam and make a judgment.

[0003] The existing detection optical path of this type generally includes a lens and an optical sensor placed on the focal plane of the lens, such as CCD, CMOS, APD, PSD, etc. Although such a detection optical path can achieve the purpose, it often requires multiple spectroscopic devices, multiple lenses, and multiple optical sensors, and has problems such as complex structure, large number of components, and large space occupied. In addition, the optical axis of the detection optical path itself is difficult to stabilize, so the measurement error is large. Summary of the invention

[0004] The purpose of the present invention is to solve the above-mentioned problems existing in the prior art and to provide a light beam coaxiality detection device, which includes a spectroscopic focusing device 1 and an optical imaging device 2, wherein the optical imaging device 2 is located on the focal plane of the spectroscopic focusing device 1; the spectroscopic focusing device 1 includes N (N≥2) transmission areas, and each transmission area can transmit a different light beam wavelength range; N corresponding imaging areas are arranged on the optical imaging device 2, and each imaging area can receive a group of light beams for imaging there.

[0005] Furthermore, the spectroscopic focusing device 1 is composed of at least two optical elements arranged in series along the optical axis, the optical elements are bonded together or dispersedly arranged at a certain distance, and N transmission areas are arranged on the optical element close to the multi-wavelength mixed light beam.

[0006] Furthermore, the light splitting and focusing device 1 is composed of a pyramid and a lens, which are coaxially arranged and the lens is close to the optical imaging device 2. Each edge of the pyramid divides its surface into N transmission areas. The pyramid is mainly used for light splitting, and the lens is mainly used for focusing.

[0007] Furthermore, the spectroscopic focusing device 1 is formed by splicing or bonding N lens blocks or grating blocks, each lens block or grating block corresponds to a transmission area, and the optical axes of the lens blocks or grating blocks are different and can only transmit light beams within a specific wavelength range.

[0008] Furthermore, the light splitting and focusing device 1 further comprises a light-proof frame, and the lens block or the grating block is fixed in the light-proof frame by means of embedding.

[0009] Furthermore, the spectroscopic focusing device 1 is an indivisible whole optical element (such as an integrated diffractive optical device), and the surface of the element or device is divided into N transmission areas, each area has a different optical axis and can only transmit light beams within a specific wavelength range.

[0010] Furthermore, the specific value of N is 3, 4, and 5.

[0011] Furthermore, when N=3, the transmission area is fan-shaped and arranged in a circular manner, and the corresponding imaging area is circular and arranged in a triangular manner.

[0012] Furthermore, when N=4, the transmission area is fan-shaped and arranged in a circular manner, and the corresponding imaging area is circular and arranged in a rectangular manner.

[0013] Furthermore, when N=5, the transmission area includes a circle at the center and four fan rings surrounding it, and the corresponding imaging area is circular and arranged in an X-shape.

[0014] The second object of the present invention is to provide a method for detecting the coaxiality of each light beam in a multi-wavelength mixed light beam using the above-mentioned device, comprising: fixing the detection device on the optical path of the multi-wavelength mixed light beam, and after the multi-wavelength mixed light beam passes through each transmission area on the spectroscopic focusing device 1, a light spot is formed on each imaging area of ​​the optical imaging device 2, and the central position and size of each light spot are detected and compared with the position and size of the standard light spot, thereby determining the beam direction and divergence angle of the light beams of different wavelengths.

[0015] Compared with the existing similar technologies, the advancement of the present invention is reflected in the following aspects: (1) Only two relatively simple optical devices, namely the spectroscopic focusing device and the optical imaging device, are needed to focus the lights of various wavelengths in the multi-wavelength mixed light beam into different areas of the same imaging device, thereby realizing the measurement of parameters such as the optical axis direction and divergence angle of lights of different wavelengths by one imaging device; (2) The structural forms of the spectroscopic focusing device and the optical imaging device are flexible and changeable, which can adapt to mixed light beams of different numbers of wavelengths and meet different application scenarios and usage requirements; (3) The structure of the detection device is relatively simple, and has a series of advantages such as a small number of components, small space occupied, and stable and reliable, which is very conducive to the miniaturization of a multi-wavelength synthesis device with a dynamic adjustment function. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a side view of the light beam coaxiality detection device in Example 1.

[0017] Figure 2 for Figure 1 Front view schematic diagram of the mid-beam focusing device.

[0018] Figure 3 for Figure 1 Front view schematic diagram of the optical imaging device.

[0019] Figure 4 This is a side view of the light beam coaxiality detection device in Example 2.

[0020] Figure 5 for Figure 4 Front view schematic diagram of the mid-beam focusing device.

[0021] Figure 6 for Figure 4 Front view schematic diagram of the optical imaging device.

[0022] Figure 7 This is a side view of the light beam coaxiality detection device in Example 3.

[0023] Figure 8 for Figure 7 Front view schematic diagram of the mid-beam focusing device.

[0024] Fig. 9 for Figure 7 Front view schematic diagram of the optical imaging device.

[0025] Among them: 1 spectroscopic focusing device, 2 optical imaging device, 3 multi-wavelength mixed light beam; 1-1 transmission area a, 1-2 transmission area b, 1-3 transmission area c, 1-4 transmission area d, 1-5 transmission area e, 1-6 tetrahedron, 1-7 lens; 2-1 imaging area a, 2-2 imaging area b, 2-3 imaging area c, 2-4 imaging area d, 2-5 imaging area e; 3-1a wavelength light, 3-2b wavelength light, 3-3c wavelength light, 3-4d wavelength light, 3-5e wavelength light. DETAILED DESCRIPTION

[0026] In order to enable ordinary technicians in the field to fully understand the technical solutions and beneficial effects of the present invention, further description is given below in conjunction with specific embodiments and drawings.

[0027] It should be emphasized that the embodiments listed below are only preferred implementations of the present invention, and simple replacements or improvements made thereon still fall within the protection scope of the present invention.

[0028] Example 1

[0029] like Figure 1A device for detecting the coaxiality of a multi-wavelength mixed light beam is shown, which is composed of a light splitting and focusing device 1 and an optical imaging device 2, which are arranged one after the other on the optical axis at a certain distance. During the test, the multi-wavelength mixed light beam 3 passes through the light splitting and focusing device 1 and the optical imaging device 2 from left to right in sequence, and forms a light spot on the optical imaging device 2.

[0030] like Figure 2 As shown, the spectroscopic focusing device 1 is circular, and is formed by gluing three fan-shaped lens blocks or grating blocks of the same size (or different sizes), or by embedding three lens blocks or grating blocks in an opaque frame. The optical axes of the three lens blocks or grating blocks are different, and each lens block or grating block can only transmit light within a certain wavelength range, and each lens block or grating block can transmit different wavelengths of light beams. As a result, the spectroscopic focusing device 1 is divided into three transmission areas (1-1 to 1-3), namely, transmission area a, transmission area b, and transmission area c, and each lens block or grating block corresponds to a transmission area.

[0031] like Figure 3 As shown, since the optical imaging device 2 is located on the focal plane of the spectroscopic and focusing device 1, the three beams of light 3-1 to 3-3 with different wavelengths (i.e., light of wavelength a, light of wavelength b, and light of wavelength c) separated by each transmission area of ​​the spectroscopic and focusing device 1 will form three light spots on the optical imaging device 2, and these light spots fall on the imaging areas 2-1 to 2-3 on the optical imaging device 2 (i.e., imaging area a, imaging area b, and imaging area c).

[0032] Reasonable design of the outgoing optical axis of the light-transmitting area of ​​the beam splitting and focusing device 1 can ensure that the light spots formed by each light beam in the multi-wavelength mixed light beam 3 on the optical imaging device 2 do not overlap each other. By calibrating in advance, the standard light spot position and size (such as Figure 6 , 9 The actual measured position and size of each light spot (as shown in the dashed circle in the figure) Figure 6 , 9 By comparing the position and size of the standard light spot (shown as the solid circle in the middle), the direction and divergence angle of each wavelength in the actual incident light beam can be accurately calculated.

[0033] Example 2

[0034] like Figure 4 A device for detecting the coaxiality of a multi-wavelength mixed light beam is shown, and the device is composed of a light splitting and focusing device 1 and an optical imaging device 2 arranged front and back along the optical axis. During the test, the multi-wavelength mixed light beam 3 passes through the light splitting and focusing device 1 and the optical imaging device 2 from left to right in sequence, and forms a light spot on the optical imaging device 2.

[0035] like Figure 5 As shown, the light splitting and focusing device 1 is an integrated circular diffractive optical device, the optical surface on the left side of which is divided into five parts, including the central transmission area 1-5 and the transmission areas 1-1 to 1-4 surrounding it, and the optical surface on the right side can be a spherical surface or an aspherical surface (such as a plane). Similarly, each transmission area can only transmit light within a certain wavelength range, and each transmission area can transmit different wavelengths of light beams.

[0036] like Figure 6 As shown, the optical imaging device 2 is provided with 5 imaging areas, which correspond to imaging area a 2-1, imaging area b 2-2, imaging area c 2-3, imaging area d 2-4, and imaging area e 2-5. Since the optical imaging device 2 is located on the focal plane of the light-splitting and focusing device 1, the five beams of light 3-1 to 3-5 with different wavelengths separated by each transmission area of ​​the light-splitting and focusing device 1 will form five light spots in each imaging area on the optical imaging device 2. By comparing the position and size of each light spot actually obtained with the position and size of the pre-calibrated standard light spot, the direction and divergence angle of each wavelength light beam in the actual incident light beam can be calculated.

[0037] Example 3

[0038] like Figure 7 A device for detecting the coaxiality of a multi-wavelength mixed light beam is shown, and the device is composed of a light splitting and focusing device 1 and an optical imaging device 2 arranged front and back along the optical axis. During the test, the multi-wavelength mixed light beam 3 passes through the light splitting and focusing device 1 and the optical imaging device 2 from left to right in sequence, and forms a light spot on the optical imaging device 2.

[0039] like Figure 7 As shown, the light splitting and focusing device 1 is assembled from a quadrangular pyramid 1-6 and a lens 1-7, which can be directly bonded together (as shown in the figure above) or coaxially fixed together at a certain distance (as shown in the figure below). Figure 8 As shown, the edges of the quadrangular pyramid 1-6 divide the optical surface of the light-splitting and focusing device 1 into four planes, thereby forming transmission areas 1-1 to 1-4. Each transmission area can only transmit light within a certain wavelength range, and each transmission area can transmit light beams of different wavelengths.

[0040] like Fig. 9As shown, the optical imaging device 2 is provided with four imaging areas, namely, imaging area a 2-1, imaging area b 2-2, imaging area c 2-3, and imaging area d 2-4. Since the optical imaging device 2 is located on the focal plane of the light-splitting and focusing device 1, the four beams of light 3-1 to 3-4 with different wavelengths separated by each transmission area of ​​the light-splitting and focusing device 1 will form four light spots in each imaging area on the optical imaging device 2. By comparing the position and size of each light spot actually obtained with the position and size of the pre-calibrated standard light spot, the direction and divergence angle of each wavelength light beam in the actual incident light beam can be calculated.

[0041] The present invention not only greatly simplifies the structure of the coaxial detection optical path, reduces the number of components of the entire device, and reduces the space and volume occupied by the equipment, but also improves the stability of the optical path and reduces the detection error, thereby realizing the miniaturization and portability of the coaxial detection optical path.

Claims

1. A light beam coaxiality detection device, characterized in that: The detection device includes a spectroscopic focusing device and an optical imaging device, wherein the optical imaging device is located on the focal plane of the spectroscopic focusing device; the spectroscopic focusing device includes N transmission areas, each of which can transmit a different range of light beam wavelengths; N corresponding imaging areas are arranged on the optical imaging device, each of which can receive a group of light beams for imaging; wherein N≥2.

2. The light beam coaxiality detection device according to claim 1, characterized in that: The light splitting and focusing device is formed by at least two optical elements arranged in series along the optical axis. The optical elements are bonded together or dispersedly arranged at a certain distance. N transmission areas are arranged on the optical element close to the multi-wavelength mixed light beam.

3. The light beam coaxiality detection device according to claim 2, characterized in that: The light splitting and focusing device is composed of a pyramid and a lens, which are coaxially arranged and the lens is close to the optical imaging device. Each edge of the pyramid divides its surface into N transmission areas.

4. The light beam coaxiality detection device according to claim 1, characterized in that: The spectroscopic focusing device is formed by splicing or bonding N lens blocks or grating blocks, each lens block or grating block corresponds to a transmission area, the optical axes of the lens blocks or grating blocks are different and can only transmit light beams within a specific wavelength range.

5. The light beam coaxiality detection device according to claim 4, characterized in that: The light splitting and focusing device also includes a light-proof frame, and the lens block or the grating block is embedded in the light-proof frame.

6. The light beam coaxiality detection device according to claim 1, characterized in that: The light splitting and focusing device is an integrated diffraction optical device, the surface of which is divided into N transmission areas, the optical axis of each area is different and can only transmit light beams within a specific wavelength range.

7. The light beam coaxiality detection device according to claim 1, characterized in that: N=3, the transmission area is fan-shaped and arranged in a circular manner, and the corresponding imaging area is circular and arranged in a triangular manner.

8. The light beam coaxiality detection device according to claim 1, characterized in that: N=4, the transmission area is fan-shaped and arranged in a circular manner, and the corresponding imaging area is circular and arranged in a rectangular manner.

9. The light beam coaxiality detection device according to claim 1, characterized in that: N=5, the transmission area includes a circle at the center and four fan rings surrounding it, and the corresponding imaging area is circular and arranged in an X shape.

10. A method for detecting the coaxiality of each light beam in a multi-wavelength mixed light beam using the device according to any one of claims 1 to 9, characterized in that The method includes: fixing the detection device on the optical path of the multi-wavelength mixed light beam, after the multi-wavelength mixed light beam passes through each transmission area on the spectroscopic focusing device, forming a light spot on each imaging area of ​​the optical imaging device, detecting the central position and size of each light spot and comparing them with the position and size of the standard light spot, thereby determining the beam direction and divergence angle of the light beams of different wavelengths.

Images