Spectral analysis equipment

Abstract

The invention relates to spectral analysis equipment which comprises a shell and a light path assembly arranged in the shell, and a main light path formed by the light path assembly is configured to be propagated along an XY plane; the device further comprises at least one light trap for suppressing stray light; the light trap comprises a plurality of blades which are arranged at intervals, a light absorption cavity is formed between every two adjacent blades, and the extension direction of each light absorption cavity deviates from the XY plane; the extension direction of the light absorption cavity of the light trap deviates from the plane where the main light path is located, after stray light enters the light absorption cavity, the main propagation and reflection direction of the stray light is forcibly changed and is not parallel to the main signal light path any more, and therefore the possibility that the escaping stray light converges into the main light path again is cut off, and even if a small amount of light is not completely absorbed and escaped, the light trap can be used for the light trap. And the emergent direction of the laser deviates from the original interference path and is difficult to reach the detector, so that the fundamental optimization from the path isolation level is realized.

Description

Technical Field

[0001] This invention relates to the field of optical analysis instrument technology, and specifically to a spectral analysis device. Background Technology

[0002] In optical instruments such as spectrometers, microscopes, and telescopes, stray light is a critical issue that seriously affects analytical accuracy and imaging quality. Stray light refers to unwanted light rays outside the main optical path of the target. Its sources include leakage of external ambient light and reflection and scattering from internal optical components, mechanical supports, and internal walls of the instrument. When this stray light reaches the detector, it will reduce the signal-to-noise ratio, contrast, and measurement accuracy.

[0003] In spectral analysis and precision optical systems, suppressing stray light is a key step in ensuring signal purity and measurement accuracy. Currently, one common technique is to use optical trap structures, such as V-grooves, sawtooth structures, or tilted blade groups placed beside the optical path. These structures suppress stray light by causing it to undergo multiple reflections within them, thereby gradually attenuating its energy.

[0004] However, existing optical trap structures are usually arranged perpendicular or nearly perpendicular to the main optical path, meaning that the extension direction of the optical absorption cavity is perpendicular or nearly perpendicular to the main optical path. This approach has obvious limitations. First, when stray light enters the optical trap at a large incident angle, its surface reflectivity may increase significantly, causing the stray light to be insufficiently absorbed and easily escape from the trap. More importantly, the propagation direction of the escaped stray light is often still close to the original main optical path direction, so there is a high probability that it will eventually enter the detector, interfering with the target spectral signal and affecting the signal-to-noise ratio and measurement accuracy of the system. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a spectral analysis device that employs a novel transverse light trap structure, which can more effectively suppress stray light and change the propagation direction of escaping stray light to avoid interfering with the main optical path signal.

[0006] To achieve the above objectives, the present invention provides a spectral analysis device, including a housing and an optical path assembly disposed within the housing, wherein the main optical path formed by the optical path assembly is configured to propagate along an XY plane; the device further includes at least one optical trap for suppressing stray light; The light trap includes multiple blades spaced apart from each other, with a light absorption cavity formed between adjacent blades, and the extension direction of the light absorption cavity deviates from the XY plane; The light absorption cavity is used to guide stray light entering it to propagate in a direction deviating from the XY plane and undergo multiple reflections and attenuation.

[0007] By adopting this technical solution, the optical trap, whose extension direction of the optical absorption cavity deviates from the XY plane of the main optical path, causes stray light to be reflected and attenuated in the direction deviating from the plane of the main optical path. This physically separates the attenuation path of stray light from the propagation path of the main signal, ensuring that even if stray light escapes from the optical trap, its propagation direction has changed and it is difficult to recouple into the main optical path propagating along the XY plane. This significantly reduces the interference of stray light on the detector in principle.

[0008] Furthermore, the blades are arranged at intervals along a direction parallel to the XY plane, so that the extension direction of the light absorption cavity is perpendicular to the Z direction, which is perpendicular to the XY plane.

[0009] By adopting this technical solution, this arrangement ensures that the extension direction of the light absorption cavity is strictly perpendicular to one of the principal axes in the three-dimensional space defined by the XY plane and the Z direction. The structure is regular, easy to process and assemble. At the same time, it clearly defines that stray light is guided to the dimension (Z direction) that is completely orthogonal to the main optical path plane for attenuation, achieving maximum path isolation.

[0010] Furthermore, the optical path assembly includes an incident component, a collimating component, a beam splitting component, a focusing component, and a detection component arranged sequentially along the main optical path.

[0011] By adopting this technical solution, the applicable typical equipment environment is limited, ensuring that the light trap structure can be seamlessly integrated into a general spectrometer architecture, thus enhancing its practicality.

[0012] Furthermore, the light trap is installed in the space between any two of the incident component, collimation component, beam splitting component, focusing component, and detection component.

[0013] By adopting this technical solution, an optimal layout scheme can be provided, which can set up traps near the source of stray light to achieve source interception and maximize the suppression effect, while not interfering with the core optical path design.

[0014] Furthermore, the light absorption cavity has a cross-sectional shape in the Z direction that is either U-shaped or conical.

[0015] This technical solution provides an optimized geometric configuration: the U-shaped cavity is easy to process and has a stable reflection path, while the conical cavity is conducive to the propagation of light into the depth and increases the number of reflections. Both can effectively promote the absorption and attenuation of light energy.

[0016] Furthermore, the blade surface is mirror-like and coated with a light-absorbing coating.

[0017] By adopting this technical solution, the specific means to achieve efficient attenuation are clarified: the mirror ensures that stray light is reflected directionally within the cavity, avoiding escape caused by diffuse scattering; the absorption coating continuously consumes light energy with each reflection; the combination of the two is the key to realizing the core physical process of multiple reflections + successive absorption.

[0018] Furthermore, the light trap is disposed on the inner wall of the housing, and its position avoids the main light path.

[0019] By adopting this technical solution, it is applicable to utilizing idle space within the equipment or to absorb stray light generated by reflection and scattering from the casing itself, thereby improving the flexibility of the design and the comprehensiveness of the suppression effect.

[0020] Compared with the prior art, the present invention has the following advantages: 1. By causing the extension direction of the optical absorption cavity of the optical trap to deviate from the XY plane where the main optical path is located, when stray light enters the optical absorption cavity, its main propagation and reflection directions are forcibly changed and are no longer parallel to the main signal optical path. This physically cuts off the possibility of the escaping stray light re-entering the main optical path. Even if a small amount of light is not completely absorbed and escapes, its outgoing direction has deviated from the original interference path and is difficult to reach the detector, thus achieving fundamental optimization at the path isolation level.

[0021] 2. This light trap structure can be flexibly installed on the inner wall of the housing or in the empty space between various optical components, without occupying the main optical path space, and is easy to modify or integrate into the existing equipment architecture. Attached Figure Description

[0022] Figure 1 This is a top view of the internal structure of the spectral analysis device in this invention; Figure 2 This is a three-dimensional partial schematic diagram of the internal structure of the spectral analysis device in this invention; Figure 3 This is a schematic lateral cross-sectional view of the optical trap in the spectral analysis device of the present invention; Figure 4 This is a schematic diagram showing the performance comparison of the same device before and after improvement, tested using a filter with a center wavelength of 600nm. Figure 5 This is a schematic diagram showing the performance comparison of the same device before and after improvement, tested using a filter with a center wavelength of 900nm.

[0023] Explanation of reference numerals in the attached drawings: 1. Housing; 2. Incident assembly; 3. Collimation assembly; 4. Beam splitting assembly; 5. Focusing assembly; 6. Detection assembly; 7. Light trap; 71. Blade; 72. Light absorption cavity. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0025] This invention provides a spectral analysis device, the core improvement of which lies in the introduction of a laterally arranged light trap 7 structure, such as... Figure 1 As shown, the device housing 1 is equipped with a series of optical path components that constitute the main optical path, including an incident component 2, a collimating component 3, a beam splitting component 4, a focusing component 5, and a detection component 6. The main optical path propagates along a pre-designed XY plane.

[0026] The structure of the light trap 7 of the present invention is as follows Figure 1 , Figure 2 As shown, it includes several blades 71 closely arranged along the Z direction (i.e., the direction perpendicular to the XY plane), with narrow gaps formed between adjacent blades 71, i.e., light absorption cavities 72; the light absorption cavity 72 has a cross-section parallel to the Z axis (i.e., Figure 2 The side cross-sectional view shown presents a conical shape (as shown). Figure 3 As shown) or U-shaped, the surface of blade 71 is polished to form a mirror finish and further coated with a high-absorption black coating (such as a black anodized layer or a special black paint).

[0027] The installation location of the light trap 7 is very flexible; in a preferred embodiment, such as... Figure 1 As shown, it can be arranged along the inner wall of the housing 1 and strictly avoid the area traversed by the main optical path; in another embodiment, it can also be installed in the free space between any two adjacent optical components, such as between the incident component 2 and the collimating component 3, or between the beam splitting component 4 and the focusing component 5; it should be noted that in the spectral analysis device, the beam splitting component 4 is the area most prone to stray light, so in order to absorb stray light to the maximum extent, the light trap 7 is generally installed on the side of the beam splitting component 4.

[0028] In another preferred embodiment, the light absorption cavity 4 of the light trap 7 extends perpendicularly to or nearly perpendicular to the Z-direction; in other words, the light absorption cavity 4 of the light trap 7 extends parallel to or nearly parallel to the XY plane. This improved arrangement has at least the following beneficial effects: 1) The light absorption cavity 4 extends along (close to) the axis of the main optical path in space. Stray light usually enters the spectral analysis device from the side or from a non-ideal direction. When it enters the entrance of the light absorption cavity 4, it will be more easily guided to the depth of the light absorption cavity 4, regardless of the initial incident angle. After multiple reflections in the light absorption cavity 4, the energy of the light gradually decreases and is eventually absorbed. This arrangement makes the propagation path of stray light after entering the cavity naturally limited to the axial direction or close to the axial direction, reducing the chance of the light directly bouncing away and escaping.

[0029] 2) In a traditional vertical arrangement (where the extension direction of the light absorption cavity 4 is perpendicular to the XY plane), when stray light strikes the surface of the light trap 7 at a large incident angle (such as close to a grazing angle), the surface reflectivity increases significantly (especially for smooth surfaces), causing the light to easily reflect and escape. However, in the arrangement described in this embodiment, after the stray light enters the cavity, it usually interacts with the cavity wall at a relatively small incident angle (close to the normal). This is because the axial extension direction of the light absorption cavity 4 is consistent with (or nearly consistent with) the main optical path. After the stray light enters, the angle between its propagation direction and the cavity wall is closer to perpendicular, thereby reducing the surface reflectivity and improving the absorption efficiency. Based on the above reasons, the arrangement adopted in this embodiment makes the stray light capture effect of the light absorption cavity 4 less affected by the incident angle. Therefore, during design and installation, it is not necessary to estimate the most likely incident angle of the stray light in advance, nor is it necessary to repeatedly adjust the installation angle of the light trap 7. It is only necessary to ensure that the light absorption cavity 4 is aligned along the main optical path direction to effectively suppress stray light at different angles.

[0030] 3) In the traditional vertical arrangement (the extension direction of the optical absorption cavity 4 is perpendicular to the XY plane), the escaping stray light often still propagates along the direction close to the original main optical path and is easy to enter the detector; however, in the arrangement adopted in this embodiment, even if a small amount of light is not completely absorbed and escapes, its escape direction is mainly along the cavity axis of the optical absorption cavity 4 (i.e., parallel to the main optical path), rather than perpendicular or nearly perpendicular to the main optical path; this directional isolation significantly reduces the probability of escaping stray light entering the detector, thereby reducing interference with the spectral signal.

[0031] Working principle: When stray light generated inside the instrument (e.g., by non-working order diffraction of the beam splitter 4 or scattering from the inner wall) is incident on the light trap 7 region, it will enter the light absorption cavity 72 between the blades 71. Since the blades 71 are arranged along the Z direction, the stray light will be reflected back and forth along the Z direction between the two opposing mirror blades 71. With each reflection, part of the light energy is absorbed by the absorption coating on the surface of the blades 71. After multiple reflections, most of the stray light energy is attenuated. Most importantly, even if a very small amount of light is not absorbed and escapes from the light trap 7, since its last reflection direction is along the Z direction, its exit direction is also basically along the Z direction, which is perpendicular to the direction of the main light path propagating in the XY plane. Therefore, it cannot be coupled into the main light path and received by the detector.

[0032] Experimental verification and effect data: To quantitatively evaluate the stray light suppression effect of the transverse light trap structure of this application, the industry standard test method - the cutoff filter method - was used to test the prototype of the spectral analysis equipment that applied the structure, and the results were compared with those of the traditional structure.

[0033] 1. Testing method: Strictly follow the standard procedure for the cutoff filter method in the appendix: Testing instruments: Spectroscopic analysis equipment of the same type as the traditional structure (before improvement) and the structure of this invention (after improvement).

[0034] Test tools: Long-pass filters with cut-on wavelengths of 600nm and 900nm were selected respectively.

[0035] Measurement and Calculation: For each equipment / filter combination, the signal intensity is measured near the cutoff wavelength and in the passband region of each filter. After deducting the dark current, the stray light rate is calculated according to the standard formula.

[0036] 2. Comparison of data and explanation of results: As attached Figure 4 and attached Figure 5 The performance comparison chart shown provides direct evidence for performance comparison: Traditional structure (before improvement): As shown by the orange curve, when tested with a filter with a center wavelength of 600nm, it exhibits a certain level of stray light in the cutoff region; when tested with a filter with a center wavelength of 900nm (again, the orange curve represents the same device before improvement), its stray light level exhibits specific characteristics in the corresponding wavelength band.

[0037] The structure of this invention (after improvement): As shown by the blue curve, the same device was tested using the same 600nm and 900nm filters after applying the transverse light trap structure of this invention.

[0038] The core conclusion is that by comparing the orange (before improvement) and blue (after improvement) curves under the same center wavelength filter test, it can be clearly seen that at each test wavelength point (whether it is the test area corresponding to the 600nm or 900nm filter), the stray light level exhibited by the device using the structure of this invention (blue curve) is significantly lower than that of the traditional structure device (orange curve) under the same test conditions. This directly proves that the transverse light trap structure of this invention can work effectively in different wavelength bands, and its stray light suppression capability is comprehensively superior to that of the traditional structure.

[0039] 3. Experimental conclusions: Through standardized cutoff filter testing and comparative diagrams under the same conditions, it was confirmed that the transverse light trap structure of the present invention can significantly and consistently improve the stray light suppression performance of spectral analysis equipment in multiple spectral bands (such as the test range corresponding to 600nm and 900nm filters). By changing the attenuation path and direction of stray light, this structure effectively reduces the overall stray light level of the system, thereby providing a reliable hardware guarantee for obtaining higher measurement accuracy and signal-to-noise ratio.

[0040] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. Those skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention shall be defined by the appended claims.

Claims

1. A spectral analysis device, comprising a housing and an optical path assembly disposed within the housing, wherein the main optical path formed by the optical path assembly is configured to propagate along an XY plane; characterized in that: The device also includes at least one optical trap for suppressing stray light; The light trap includes multiple blades spaced apart from each other, with a light absorption cavity formed between adjacent blades, and the extension direction of the light absorption cavity deviates from the XY plane; The light absorption cavity is used to guide stray light entering it to propagate in a direction deviating from the XY plane and undergo multiple reflections and attenuation.

2. The spectral analysis device according to claim 1, characterized in that, The blades are arranged at intervals along a direction parallel to the XY plane, so that the extension direction of the light absorption cavity is perpendicular to the Z direction, which is perpendicular to the XY plane.

3. The spectral analysis device according to claim 1, characterized in that: The optical path assembly includes an incident component, a collimation component, a beam splitting component, a focusing component, and a detection component arranged sequentially along the main optical path.

4. The spectral analysis device according to claim 3, characterized in that: The optical trap is installed in the space between any two of the incident component, collimation component, beam splitting component, focusing component, and detection component.

5. The spectral analysis apparatus according to claim 1, characterized in that: The light absorption cavity has a cross-sectional shape in the Z direction that is either U-shaped or conical.

6. The spectral analysis apparatus according to claim 1, characterized in that: The blade surface is mirror-like and coated with a light-absorbing coating.

7. The spectral analysis apparatus according to claim 1, characterized in that: The light trap is disposed on the inner wall of the housing, and its position avoids the main light path.

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