Backscattering stray light detection device and method

Abstract

The invention relates to the field of optical measurement, and discloses a backscattering stray light detection device and method, in the device, after a light beam emitted by a light source module is processed by a light beam processing module, the light beam is divided into a transmission light beam and a reflection light beam by a light splitting flat plate; the transmission light beam enters the unit to be measured to generate back scattering stray light, and the reflection light beam is absorbed by the light absorption module to prevent the reflection light beam from interfering with the measurement result. In addition, the light beam collection module collects back scattering stray light returned from the unit to be detected, and the back scattering stray light is detected through the detector module. According to the design, the influence of stray light is reduced, the sensitivity and accuracy of detection are improved through the synergistic effect of the light absorption module and the light beam collection module, the detection level can be improved to 10 <-10 > W magnitude, more accurate data are provided for gravitational wave measurement, and the precision and reliability of gravitational wave detection are improved.

Description

Technical Field

[0001] The present invention relates to the field of optical measurement, and more particularly to a backscattered stray light detection device and method. Background Art

[0002] Gravitational wave detection is one of the frontiers of contemporary physics research, and interstellar laser interferometry is the key to high-precision gravitational wave detection. In this technology, telescopes, as one of the core payloads, are crucial to improving the efficiency of light beam transmission between satellites. In order to detect gravitational wave signals in the 0.1mHz to 1Hz frequency band, based on the interstellar laser interferometer arm length of about 170,000 kilometers, it is necessary to increase the interstellar displacement measurement accuracy to picometers per square root of hertz (pm / Hz). 1 / 2 ) level. This extremely high precision requirement poses great challenges to the design and manufacture of telescopes, especially in terms of stray light control.

[0003] At present, intersatellite laser interferometry systems generally use a laser transceiver multiplexing design. Under this design, when a 4-watt transmitted laser reaches a remote satellite, the received power is only on the order of 10 nanowatts. Under such weak signal conditions, the backscattering of the receiving telescope may have a significant impact on the final beat signal. In order to ensure measurement accuracy, the stray light (mainly backscattering) of the entire system needs to be controlled within 10 -10 However, it is difficult for traditional testing methods to effectively remove the impact of external stray light on detection, resulting in aliasing of external stray light and backscattered light, which seriously affects the accuracy of stray light measurement. This problem restricts further improvement of telescope performance and also limits the application potential of interstellar laser interferometry systems in gravitational wave detection. Summary of the invention

[0004] In order to reduce the influence of external stray light in backscattering measurement and improve the accuracy of gravitational wave measurement, the present invention proposes the following technical solutions:

[0005] In a first aspect, the present invention provides a backscattered stray light detection device, comprising:

[0006] The light source module is used to emit a light beam.

[0007] The light beam processing module is used to shape, collimate and / or expand the light beam emitted by the light source module.

[0008] The beam splitter plate is used to split the light beam processed by the light beam processing module into a transmitted light beam and a reflected light beam.

[0009] The unit to be tested is arranged on the transmission light path of the light splitting plate, and is used to receive the transmission light beam and generate backscattered stray light.

[0010] The light absorption module is arranged on the reflected light path of the light splitting plate and is used for absorbing the reflected light beam.

[0011] The light beam collection module is arranged between the light splitting plate and the detector module, and is used to collect the backscattered stray light returned from the unit to be tested and reflected by the light splitting plate.

[0012] The detector module is connected to the light beam collection module and is used to receive and detect the backscattered stray light collected by the light beam collection module.

[0013] As a preferred technical solution, the reflected light path between the beam splitter plate and the unit to be measured, and the reflected light path between the beam splitter plate and the beam collecting module are connected through a connected light shield.

[0014] As a preferred technical solution, the beam splitter plate is a circular plate with a diameter of 25 mm and a thickness of 10.06 mm.

[0015] As a preferred technical solution, the beam splitter plate includes an incident surface and an exit surface.

[0016] The incident surface of the beam splitter plate is coated with an anti-reflection film, and the output surface is coated with a semi-transparent and semi-reflective film.

[0017] The beam splitter plate is tilted so that the light beam is incident on the light beam incident surface at an angle of 50°.

[0018] As a preferred technical solution, both the incident surface and the exit surface of the beam splitter plate are provided with light apertures.

[0019] The light splitting plate is coated with a black coating in areas other than the light clearing aperture.

[0020] As a preferred technical solution, the light absorption module includes a light trap, the residual reflectivity of the light trap is 10 -6 the following.

[0021] As a preferred technical solution, the light beam collection module includes a lens and an aperture.

[0022] The lens is installed on the reflected light path of the beam splitter plate, and the focus of the lens is located on the detector surface of the detector module.

[0023] The aperture is arranged on the optical path between the lens and the detector module to eliminate other stray light propagating along the optical path.

[0024] As a preferred technical solution, the detector module includes a phototube and an amplifier.

[0025] The photoelectric tube is used to convert the received light signal into an electrical signal.

[0026] The amplifier is used to amplify the electrical signal output by the photoelectric tube.

[0027] As a preferred technical solution, the light beam emitted by the light source module is a 1064nm laser.

[0028] In a second aspect, the present invention further provides a backscattered stray light detection method, which is applied to the backscattered stray light detection device as described in any solution of the first aspect, comprising:

[0029] Use the Light Source module to emit a light beam.

[0030] The light beam processing module is used to shape, collimate and / or expand the light beam emitted by the light source module.

[0031] The light beam processed by the light beam processing module is divided into a transmitted light beam and a reflected light beam by a light splitting plate.

[0032] The unit to be tested is arranged on the transmission light path of the light splitting plate, receives the transmission light beam and generates backscattered stray light.

[0033] A light absorption module is arranged on the reflected light path of the beam splitter plate to absorb the reflected light beam.

[0034] A beam collecting module is arranged between the light splitting plate and the detector module to collect backscattered stray light that is returned from the unit to be tested and reflected by the light splitting plate.

[0035] A detector module connected to the light beam collection module is used to receive and detect the backscattered stray light collected by the light beam collection module.

[0036] The beneficial effects of the present invention include at least:

[0037] The light beam emitted by the light source module of the present invention is shaped, collimated and / or expanded by the light beam processing module to form a light beam characteristic suitable for subsequent measurement. Then, the spectroscopic plate divides the processed light beam into a transmitted light beam and a reflected light beam. The transmitted light beam enters the unit to be measured and generates backscattered stray light, while the reflected light beam is absorbed by the light absorption module to prevent it from interfering with the measurement result. In addition, the light beam collection module collects the backscattered stray light returned from the unit to be measured and detects it through the detector module. This design not only reduces the influence of external stray light, but also improves the sensitivity and accuracy of detection through the synergistic effect of the light absorption module and the light beam collection module, and can increase the detection level to 10 -10 W level, providing more accurate data for gravitational wave measurements and improving the accuracy and reliability of gravitational wave detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1This is a schematic diagram of the structure of the backscattered stray light detection device provided in Example 1.

[0039] Figure 2 This is a schematic diagram of the structure of the backscattered stray light detection device provided in Example 2.

[0040] Figure 3 This is a schematic structural diagram of the beam splitter plate provided in Example 2.

[0041] Figure 4 This is a schematic flow chart of the backscattered stray light detection method provided in Example 3.

[0042] Among them, there are a light source module-1, a light beam processing module-2, a spectroscopic plate-3, a unit to be tested-4, a light absorption module-5, a light beam collection module-6, a detector module-7, and a light shield-8. DETAILED DESCRIPTION

[0043] The following will describe the embodiments of the present invention with reference to the accompanying drawings and preferred technical solutions. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred technical solutions are only for illustrating the present invention, not for limiting the scope of protection of the present invention.

[0044] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0045] In the following description, numerous details are discussed to provide a more thorough explanation of the embodiments of the present invention. However, it is obvious to those skilled in the art that the embodiments of the present invention can be implemented without these specific details. In other embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail to avoid making the embodiments of the present invention difficult to understand.

[0046] Example 1

[0047] This embodiment provides a backscattered stray light detection device, such as Figure 1 As shown, Figure 1This is a schematic structural diagram of the backscattered stray light detection device provided in this embodiment, which includes: a light source module 1, a light beam processing module 2, a spectroscopic plate 3, a unit to be tested 4, a light absorption module 5, a light beam collection module 6 and a detector module 7.

[0048] In the specific implementation process, all components of the backscattered stray light detection device except the unit to be tested 4 are placed in a black box, and the inner wall is painted with black paint. The light source module 1 emits a light beam, and the light beam then enters the light beam processing module 2, in which it is shaped, collimated and / or expanded to achieve the desired characteristics of the light beam. The processed light beam reaches the spectroscopic plate 3, and the spectroscopic plate 3 divides it into two paths: one transmission light beam enters the unit to be tested 4, and the other reflected light beam enters the light absorption module 5 to be absorbed. The unit to be tested 4 receives the transmitted light beam and generates backscattered stray light, which returns from the unit to be tested 4, is reflected by the spectroscopic plate 3, and is collected by the beam collection module 6 arranged between the spectroscopic plate 3 and the detector module 7. The beam collection module 6 transmits the collected backscattered stray light to the detector module 7. The detector module 7 receives and detects the backscattered stray light signal transmitted from the beam collection module 6, and obtains relevant performance index data. In the whole process, each module needs to be precisely matched to ensure that the detection device can work normally and obtain reliable measurement results.

[0049] It can be understood that in the backscattered stray light detection device proposed in this embodiment, the light beam emitted by the light source module 1 is shaped, collimated and / or expanded by the light beam processing module 2 to form a light beam characteristic suitable for subsequent measurement. Then, the spectroscopic plate 3 divides the processed light beam into a transmitted light beam and a reflected light beam. The transmitted light beam enters the unit to be measured 4 and generates backscattered stray light, while the reflected light beam is absorbed by the light absorption module 5 to prevent it from interfering with the measurement result. In addition, the light beam collection module 6 collects the backscattered stray light returned from the unit to be measured 4 and detects it through the detector module 7. This design not only reduces the influence of external stray light, but also improves the sensitivity and accuracy of detection through the synergistic effect of the light absorption module 5 and the light beam collection module 6, and can increase the detection level to 10 -10 W level, providing more accurate data for gravitational wave measurements and improving the accuracy and reliability of gravitational wave detection.

[0050] Example 2

[0051] This embodiment makes improvements on the backscattered stray light detection device proposed in the first embodiment. Figure 2 As shown, Figure 2 A schematic diagram of the structure of the backscattered stray light detection device provided in this embodiment

[0052] In this embodiment, the reflected light path between the beam splitter plate 3 and the unit to be tested 4, and the reflected light path between the beam splitter plate 3 and the beam collecting module 6, are connected through a connected light shield 8. The inner diameter of the light shield 8 is the same as the inner beam diameter, and the inner wall is coated with a black coating.

[0053] It is understandable that the light shield 8 can effectively block the stray light on the reflected light path of the beam splitter plate 3 and the reflected light path of the beam collecting module 6, preventing the stray light from entering the detector module 7 and improving the signal-to-noise ratio of the detection system. The black coating can absorb the stray light and further reduce the interference of the detector module 7.

[0054] In this embodiment, the light beam emitted by the light source module 1 is a 1064nm laser.

[0055] In this embodiment, Figure 3 As shown, the beam splitter plate 3 is a circular plate with a diameter of 25 mm and a thickness of 10.06 mm. The beam splitter plate 3 includes an incident surface and an exit surface. The incident surface of the beam splitter plate 3 is coated with an anti-reflection film, and the exit surface is coated with a semi-transparent and semi-reflective film. The beam splitter plate 3 is tilted so that the light beam is incident on the light beam incident surface at an angle of 50°. The incident surface and the exit surface of the beam splitter plate 3 are both provided with a clear aperture, and the clear aperture is an elliptical aperture with a major axis of 7.78 mm and a minor axis of 5 mm. The beam splitter plate 3 is coated with a black coating in areas other than the clear aperture.

[0056] It is understandable that the selection of a suitable size of the spectroscopic plate 3 can meet the requirements of optical path design and device integration, and ensure that the spectroscopic plate 3 will not be deformed or damaged when subjected to the light beam, thereby ensuring the stability and reliability of the detection system. The anti-reflection film can increase the transmittance of the incident light beam, and the semi-transparent and semi-reflective film can separate the transmitted light beam from the reflected light beam, and ensure that the intensity of the reflected light beam is moderate. The tilted setting of the spectroscopic plate 3 can avoid direct reflection into the detector, further improving the signal-to-noise ratio of the detection system. The clear aperture can ensure that the light beam enters and exits the spectroscopic plate 3 smoothly, and the black coating can absorb stray light on the surface of the plate to prevent it from entering the detector module 7, thereby improving the detection sensitivity.

[0057] In this embodiment, the light absorption module 5 includes a light trap, and the residual reflectivity of the light trap is 10 -6 the following.

[0058] It is understandable that the light trap can effectively absorb the reflected light beam, ensuring that the reflected light will not enter the unit to be tested 4 or other optical elements again, avoiding interference and improving the anti-interference ability of the detection system.

[0059] In this embodiment, the beam collection module 6 includes a lens and an aperture. The lens is installed on the reflected light path of the beam splitter plate 3, and its focus is located on the detector surface of the detector module 7. The aperture is arranged on the light path between the lens and the detector module 7 to eliminate other stray light propagating along this light path.

[0060] It is understandable that the lens can effectively collect the backscattered stray light returned from the unit to be tested 4 and focus it on the detector surface to improve the detection sensitivity. The aperture can block other irrelevant stray light from entering the detector, further improving the signal-to-noise ratio.

[0061] In this embodiment, the detector module 7 includes a photoelectric tube and an amplifier. The photoelectric tube is used to convert the received light signal into an electrical signal. The amplifier is used to amplify the electrical signal output by the photoelectric tube.

[0062] It is understandable that the photoelectric tube can effectively convert the backscattered stray light signal into a measurable electrical signal. The amplifier can amplify this weak electrical signal to a level that can be analyzed and processed by subsequent circuits, further improving the detection sensitivity.

[0063] Example 3

[0064] like Figure 3 As shown, this embodiment provides a backscattered stray light detection method, which is applied to the backscattered stray light detection device as described in the above embodiment, including:

[0065] S1: Use light source module 1 to emit a light beam.

[0066] S2: using the beam processing module 2 to shape, collimate and / or expand the beam emitted by the light source module 1 .

[0067] S3: Splitting the light beam processed by the light beam processing module 2 into a transmitted light beam and a reflected light beam through the light splitting plate 3.

[0068] S4: The unit to be tested 4 is arranged on the transmission light path of the beam splitter plate 3 to receive the transmission light beam and generate backscattered stray light.

[0069] S5: Arrange a light absorbing module 5 on the reflected light path of the beam splitting plate 3 to absorb the reflected light beam.

[0070] S6: a light beam collecting module 6 is arranged between the light splitting plate 3 and the detector module 7 to collect backscattered stray light returned from the unit to be tested 4 and reflected by the light splitting plate 3 .

[0071] S7: using the detector module 7 connected to the light beam collection module 6 to receive and detect the backscattered stray light collected by the light beam collection module 6 .

[0072] It can be understood that the backscattered stray light detection method proposed in this embodiment is to form a beam characteristic suitable for subsequent measurement by subjecting the light beam emitted by the light source module 1 to shaping, collimating and / or beam expansion processing by the light beam processing module 2. Then, the spectroscopic plate 3 divides the processed light beam into a transmitted light beam and a reflected light beam. The transmitted light beam enters the unit to be measured 4, generating backscattered stray light, while the reflected light beam is absorbed by the light absorption module 5 to prevent it from interfering with the measurement result. In addition, the beam collection module 6 collects the backscattered stray light returned from the unit to be measured 4 and detects it through the detector module 7. This design not only reduces the influence of external stray light, but also improves the sensitivity and accuracy of detection through the synergistic effect of the light absorption module 5 and the beam collection module 6, and can increase the detection level to the order of 10-10W, providing more accurate data for gravitational wave measurement, and improving the accuracy and reliability of gravitational wave detection.

[0073] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0074] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "N" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0075] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0076] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array, a field programmable gate array, etc.

[0077] A person skilled in the art may understand that all or part of the steps in the above-mentioned embodiment method may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0078] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A backscattered stray light detection device, characterized in that: include: A light source module (1), used for emitting a light beam; A light beam processing module (2) is used to perform beam shaping, collimation and / or beam expansion processing on the light beam emitted by the light source module (1); A beam splitter plate (3) used for splitting the light beam processed by the light beam processing module (2) into a transmitted light beam and a reflected light beam; The unit to be tested (4) is arranged on the transmission light path of the light splitting plate (3) and is used to receive the transmission light beam and generate backscattered stray light; A light absorption module (5) is arranged on the reflected light path of the light splitting plate (3) and is used to absorb the reflected light beam; A light beam collection module (6) is arranged between the light splitting plate (3) and the detector module (7) and is used to collect backscattered stray light that is returned from the unit to be tested (4) and reflected by the light splitting plate (3); A detector module (7) is connected to the light beam collection module (6) and is used to receive and detect the backscattered stray light collected by the light beam collection module (6).

2. The backscattered stray light detection device according to claim 1, characterized in that: The reflected light path between the beam splitter plate (3) and the unit to be measured (4), and the reflected light path between the beam splitter plate (3) and the light beam collection module (6) are connected via a connected light shield (8).

3. The backscattered stray light detection device according to claim 1, characterized in that: The light splitting plate (3) is a circular plate with a diameter of 25 mm and a thickness of 10.06 mm.

4. The backscattered stray light detection device according to claim 3, characterized in that: The beam splitter plate (3) comprises an incident surface and an exit surface; The incident surface of the beam splitter plate (3) is coated with an anti-reflection film, and the output surface is coated with a semi-transparent and semi-reflective film; The beam splitter plate (3) is arranged tilted so that the light beam is incident on the light beam incident surface at an angle of 50°.

5. The backscattered stray light detection device according to claim 4, characterized in that: The incident surface and the exit surface of the beam splitter plate (3) are both provided with light apertures; The light splitting plate (3) is coated with a black coating in areas other than the light-clearing aperture.

6. The backscattered stray light detection device according to claim 1, characterized in that: The light absorption module (5) comprises a light trap, the residual reflectivity of the light trap is within 10 -6 the following.

7. The backscattered stray light detection device according to claim 1, characterized in that: The light beam collection module (6) comprises a lens and a diaphragm; The lens is installed on the reflected light path of the beam splitter plate (3), and its focus is located on the detector surface of the detector module (7); The aperture is arranged on the optical path between the lens and the detector module (7) to eliminate other stray light propagating along the optical path.

8. The backscattered stray light detection device according to claim 1, characterized in that: The detector module (7) comprises a photoelectric tube and an amplifier; The photoelectric tube is used to convert the received light signal into an electrical signal; The amplifier is used to amplify the electrical signal output by the photoelectric tube.

9. The backscattered stray light detection device according to claim 1, characterized in that: The light beam emitted by the light source module (1) is a 1064nm laser.

10. A backscattered stray light detection method, applied to the backscattered stray light detection device according to any one of claims 1 to 9, characterized in that: include: Using a light source module (1) to emit a light beam; Using the beam processing module (2) to shape, collimate and / or expand the beam emitted by the light source module (1); The light beam processed by the light beam processing module (2) is divided into a transmission light beam and a reflection light beam by a light splitting plate (3); The unit to be tested (4) is arranged on the transmission light path of the light splitting plate (3) to receive the transmission light beam and generate backscattered stray light; A light absorption module (5) is arranged on the reflected light path of the light splitting plate (3) to absorb the reflected light beam; A light beam collection module (6) is arranged between the light splitting plate (3) and the detector module (7) to collect backscattered stray light that is returned from the unit to be measured (4) and reflected by the light splitting plate (3); A detector module (7) connected to the light beam collection module (6) is used to receive and detect the backscattered stray light collected by the light beam collection module (6).

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