Three-mode composite optical system

Abstract

The invention, which relates to the optical design field, discloses a three-mode composite optical system comprising an object plane, a primary reflector, a secondary reflector, a first beam splitter, a second beam splitter, a laser system, a visible light system and a long-wave infrared system. Light emitted by an object plane is reflected to the first beam splitter through the secondary reflector and the primary reflector and is transmitted to the second beam splitter, and a light path is reflected through the second beam splitter to form a laser system; light emitted by an object plane is reflected to the first beam splitter through the secondary reflector and the primary reflector, and forms a visible light system through a reflection light path of the first beam splitter; light emitted by an object plane is reflected to the first beam splitter through the secondary reflector and the primary reflector, reaches the second beam splitter through the transmission effect of the first beam splitter, and passes through a transmission light path on the second beam splitter to form a long-wave infrared system; according to the system provided by the invention, the two beam splitters are used for splitting light, so that the cost is reduced, and the application range is wide.

Description

Technical Field

[0001] The present invention relates to the technical field of optical design, and in particular to a three-mode composite optical system. Background Art

[0002] As an important component of the composite seeker, the composite optical system detects and tracks the infrared radiation of the target and receives the laser energy reflected by the target during the flight of the missile. The multi-mode composite optical system can obtain information on the target in multiple dimensions, improve the anti-stealth, anti-interference and target recognition capabilities of the seeker, and enhance the missile's perception and penetration capabilities for wide-area information. Since multi-mode composite technology belongs to complex imaging, there are problems such as mode switching and multi-mode information fusion. In addition, the system is complex and has a large number of parts, which makes assembly and adjustment difficult. Therefore, a three-mode composite optical system is urgently needed to overcome the problems existing in the existing methods. Summary of the invention

[0003] The purpose of the present invention is to provide a three-mode composite optical system to solve the problems existing in the prior art, such as difficulty in mode switching, difficulty in multi-mode information fusion, complex system, large number of parts and difficult assembly and adjustment.

[0004] To achieve the above object, the present invention provides a three-mode composite optical system, comprising an object plane, a primary reflector, a secondary reflector, a first beam splitter, a second beam splitter, a laser system, a visible light system and a long-wave infrared system;

[0005] The light emitted from the object surface is reflected by the secondary reflector and the primary reflector to the first beam splitter, and then transmitted to the second beam splitter. After the light path is reflected by the second beam splitter, a laser system is formed.

[0006] The light emitted from the object surface is reflected by the secondary reflector and the primary reflector to the first beam splitter, and passes through the reflected light path of the first beam splitter to form a visible light system;

[0007] The light emitted from the object surface is reflected by the secondary reflector and the primary reflector to the first beam splitter, reaches the second beam splitter through the transmission effect of the first beam splitter, and passes through the transmission light path on the second beam splitter to form a long-wave infrared system.

[0008] Preferably, the laser system includes a first lens group, a first filter and a first detector; the light beam reflected on the second beam splitter passes through the first lens group and the first filter and is received by the first detector; wherein the first lens group includes a first lens, a second lens and a third lens which are sequentially arranged away from the second beam splitter.

[0009] Preferably, the front and rear curvature radii of the first lens range from 67mm to 97mm and 10mm to 40mm; the absolute value of the optical thickness ranges from 12mm to 15mm; and the optical material is H-LAK5A; the front and rear curvature radii of the second lens range from -35mm to -5mm and -64mm to -34mm; the absolute value of the optical thickness ranges from 3mm to 6mm; and the optical material is H-ZLAF76A; the front and rear curvature radii of the third lens range from -5mm to 25mm and -3mm to 27mm; the absolute value of the optical thickness ranges from 4mm to 7mm; and the optical material is H-ZLAF90.

[0010] Preferably, the visible light system includes a second lens group, a second filter and a second detector; the light beam reflected by the first beam splitter passes through the second lens group and the second filter and is received by the second detector; wherein the second lens group includes a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens which are sequentially arranged away from the first beam splitter.

[0011] Preferably, the front and rear curvature radius of the fourth lens ranges from -74mm to -44mm and 69mm to 99mm; the absolute value of the optical thickness ranges from 6mm to 9mm; and the optical material is H-ZK50GT; the front and rear curvature radius of the fifth lens ranges from -32mm to -2mm and -87mm to -57mm; the absolute value of the optical thickness ranges from 3mm to 6mm; and the optical material is H-ZLAF68B; the front and rear curvature radius of the sixth lens ranges from 1mm to 31mm and -51mm to -21mm; the absolute value of the optical thickness ranges from 2mm to 5mm; and the optical material is H-ZF88G T; the front and rear curvature radii of the seventh lens range from 95mm to 125mm and 3mm to 33mm; the absolute value of the optical thickness ranges from 3mm to 6mm; the optical material is H-ZLAF68B; the front and rear curvature radii of the eighth lens range from -91mm to -61mm and 44mm to 74mm; the absolute value of the optical thickness ranges from 3mm to 6mm; the optical material is H-ZLAF50E; the front and rear curvature radii of the ninth lens range from -33mm to -3mm and 44mm to 74mm; the absolute value of the optical thickness ranges from 12mm to 15mm; the optical material is H-ZLAF68B.

[0012] Preferably, the long-wave infrared system includes a third lens group, a third filter and a third detector; the light beam transmitted on the second beam splitter passes through the third lens group and the third filter and is received by the third detector; wherein the third lens group includes a tenth lens, an eleventh lens, a twelfth lens, a thirteenth lens, a fourteenth lens and a fifteenth lens which are arranged in sequence away from the second beam splitter.

[0013] Preferably, the front and rear curvature radii of the tenth lens range from 158mm to 188mm and -559mm to -529mm; the absolute value of the optical thickness ranges from 8mm to 11mm; and the optical material is GERMANIUM; the front and rear curvature radii of the eleventh lens range from 17mm to 47mm and 7mm to 37mm; the absolute value of the optical thickness ranges from 2mm to 5mm; and the optical material is GERMANIUM; the front and rear curvature radii of the twelfth lens range from 10mm to 40mm and 22mm to 52mm; the absolute value of the optical thickness ranges from 2mm to 5mm; and the optical material is ZNSE; The front and rear curvature radii of the lens range from -24mm to 6mm and -33mm to -3mm; the absolute value range of the optical thickness is 7mm to 10mm; the optical material is GERMANIUM; the front and rear curvature radii of the fourteenth lens range from 11mm to 41mm and -110mm to -80mm; the absolute value range of the optical thickness is 7mm to 10mm; the optical material is IRG206; the front and rear curvature radii of the fifteenth lens range from -140mm to -110mm and -289mm to -259mm; the absolute value range of the optical thickness is 13mm to 16mm; the optical material is ZNS-BROAD.

[0014] Therefore, the present invention adopts the above-mentioned three-mode composite optical system to split the three-mode light sources of laser, visible light and infrared light, and images are formed through different optical systems, which can meet the practical application needs of multi-mode composite optical system imaging performance verification, system installation and adjustment, and has good imaging effect, compact system structure and small size; the present invention can perform three-mode light source homogenization and attenuation, realize multiple light source simulation, and can meet multiple simulation test needs and meet anti-interference test needs.

[0015] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is an overall structural diagram of a three-mode composite optical system of the present invention;

[0017] Figure 2 It is a structural diagram of the laser system of the present invention;

[0018] Figure 3 is a structural diagram of the visible light system of the present invention;

[0019] Figure 4 It is a structural diagram of the long-wave infrared system of the present invention;

[0020] Figure 5 is an MTF curve diagram of the laser system of the present invention;

[0021] Figure 6is a spot diagram of the laser system of the present invention;

[0022] Figure 7 is a MTF curve diagram of the visible light system of the present invention;

[0023] Figure 8 is a spot diagram of a visible light system of the present invention;

[0024] Fig. 9 is the MTF curve diagram of the long-wave infrared system of the present invention;

[0025] Fig.10 is a spot diagram of the long-wave infrared system of the present invention;

[0026] Reference numerals

[0027] 1. Object plane; 2. Primary reflector; 3. Secondary reflector; 4. First beam splitter; 5. Second beam splitter; 6. First lens group; 7. First filter; 8. First detector; 9. Second lens group; 10. Second filter; 11. Second detector; 12. Third lens group; 13. Third filter; 14. Third detector; 15. First lens; 16. Second lens; 17. Third lens; 18. Fourth lens; 19. Fifth lens; 20. Sixth lens; 21. Seventh lens; 22. Eighth lens; 23. Ninth lens; 24. Tenth lens; 25. Eleventh lens; 26. Twelfth lens; 27. Thirteenth lens; 28. Fourteenth lens; 29. ​​Fifteenth lens. DETAILED DESCRIPTION

[0028] The following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figure 1-Figure 10 , a three-mode composite optical system, comprising an object plane 1, a primary reflector 2, a secondary reflector 3, a first beam splitter 4, a second beam splitter 5, a laser system, a visible light system and a long-wave infrared system;

[0030] The light emitted from the object plane 1 is reflected by the secondary reflector 3 and the primary reflector 2 to the first beam splitter 4, and is transmitted to the second beam splitter 5, and the light path is reflected by the second beam splitter 5 to form a laser system; the laser system includes a first lens group 6, a first filter 7 and a first detector 8; the light beam reflected on the second beam splitter 5 is received by the first detector 8 through the first lens group 6 and the first filter 7; wherein the first lens group 6 includes a first lens 15, a second lens 16 and a third lens 17 which are sequentially arranged away from the second beam splitter 5. The front and rear curvature radii of the first lens 15 range from 67mm to 97mm and 10mm to 40mm; the absolute value range of the optical thickness is 12mm to 15mm; the optical material is H-LAK5A; the front and rear curvature radii of the second lens 16 range from -35mm to -5mm and -64mm to -34mm; the absolute value range of the optical thickness is 3mm to 6mm; the optical material is H-ZLAF76A; the front and rear curvature radii of the third lens 17 range from -5mm to 25mm and -3mm to 27mm; the absolute value range of the optical thickness is 4mm to 7mm; the optical material is H-ZLAF90.

[0031] The light emitted by the object plane 1 is reflected by the secondary reflector 3 and the primary reflector 2 to the first beam splitter 4, and the light path is reflected by the first beam splitter 4 to form a visible light system; the visible light system includes a second lens group 9, a second filter 10 and a second detector 11; the light beam reflected by the first beam splitter 4 is received by the second detector 11 through the second lens group 9 and the second filter 10; wherein the second lens group 9 includes a fourth lens 18, a fifth lens 19, a sixth lens 20, a seventh lens 21, an eighth lens 22 and a ninth lens 23 which are sequentially arranged away from the first beam splitter 4. The fourth lens 18 has a front and rear curvature radius ranging from -74mm to -44mm and 69mm to 99mm; the absolute value of the optical thickness ranges from 6mm to 9mm; and the optical material is H-ZK50GT; the fifth lens 19 has a front and rear curvature radius ranging from -32mm to -2mm and -87mm to -57mm; the absolute value of the optical thickness ranges from 3mm to 6mm; and the optical material is H-ZLAF68B; the sixth lens 20 has a front and rear curvature radius ranging from 1mm to 31mm and -51mm to -21mm; the absolute value of the optical thickness ranges from 2mm to 5mm; and the optical material is H-ZF88GT; The front and rear curvature radii of the seventh lens 21 range from 95mm to 125mm and 3mm to 33mm; the absolute value of the optical thickness ranges from 3mm to 6mm; the optical material is H-ZLAF68B; the front and rear curvature radii of the eighth lens 22 range from -91mm to -61mm and 44mm to 74mm; the absolute value of the optical thickness ranges from 3mm to 6mm; the optical material is H-ZLAF50E; the front and rear curvature radii of the ninth lens 23 range from -33mm to -3mm and 44mm to 74mm; the absolute value of the optical thickness ranges from 12mm to 15mm; the optical material is H-ZLAF68B.

[0032] The light emitted from the object plane 1 is reflected by the secondary reflector 3 and the primary reflector 2 to the first beam splitter 4, and reaches the second beam splitter 5 through the transmission effect of the first beam splitter 4. The transmission light path on the second beam splitter 5 forms a long-wave infrared system. The long-wave infrared system includes a third lens group 12, a third filter 13 and a third detector 14; the light beam transmitted on the second beam splitter 5 is received by the third detector 14 through the third lens group 12 and the third filter 13; wherein the third lens group 12 includes a tenth lens 24, an eleventh lens 25, a twelfth lens 26, a thirteenth lens 27, a fourteenth lens 28 and a fifteenth lens 29 which are sequentially arranged away from the second beam splitter 5. The tenth lens 24 has a front and rear curvature radius ranging from 158mm to 188mm and -559mm to -529mm; the absolute value of the optical thickness ranges from 8mm to 11mm; the optical material is GERMANIUM; the eleventh lens 25 has a front and rear curvature radius ranging from 17mm to 47mm and 7mm to 37mm; the absolute value of the optical thickness ranges from 2mm to 5mm; the optical material is GERMANIUM; the twelfth lens 26 has a front and rear curvature radius ranging from 10mm to 40mm and 22mm to 52mm; the absolute value of the optical thickness ranges from 2mm to 5mm; the optical material is ZNSE; the thirteenth lens The front and rear curvature radii of 27 range from -24mm to 6mm and -33mm to -3mm; the absolute value range of optical thickness is 7mm to 10mm; the optical material is GERMANIUM; the front and rear curvature radii of the fourteenth lens 28 range from 11mm to 41mm and -110mm to -80mm; the absolute value range of optical thickness is 7mm to 10mm; the optical material is IRG206; the front and rear curvature radii of the fifteenth lens 29 range from -140mm to -110mm and -289mm to -259mm; the absolute value range of optical thickness is 13mm to 16mm; the optical material is ZNS-BROAD.

[0033] Example

[0034] It should be noted that the negative thickness in the embodiment indicates the negative propagation thickness along the light propagation direction in the optical design, which is in line with the modeling habits of optical software.

[0035] In this embodiment, the first lens 15 has a front and rear curvature radius of 82.414 mm and 25.065 mm; an optical thickness of -13.587 mm; and an optical material of H-LAK5A; the second lens 16 has a front and rear curvature radius of -20.081 mm and -49.488 mm; an optical thickness of -4.524 mm; and an optical material of H-ZLAF76A; the third lens 17 has a front and rear curvature radius of 9.910 mm and 12.384 mm; an optical thickness of -6.043 mm; and an optical material of H-ZLAF90, wherein Table 1 shows the specific parameters of each optical element

[0036] Table 1

[0037]

[0038]

[0039] In this embodiment, the front and rear curvature radii of the fourth lens 18 are -59.245mm and 83.560mm; the optical thickness is -6.628mm; the optical material is H-ZK50GT; the front and rear curvature radii of the fifth lens 19 are -16.853mm and -72.441mm; the optical thickness is -3.876mm; the optical material is H-ZLAF68B; the front and rear curvature radii of the sixth lens 20 are 15.664mm and -35.716mm; the optical thickness is -3.300mm; the optical material is H-ZF88GT; the seventh lens 2 1 front and rear curvature radii are 109.632mm and 17.755mm; the optical thickness is -4.637mm; the optical material is H-ZLAF68B; the eighth lens 22 front and rear curvature radii are -76.027mm and 58.737mm; the optical thickness is -3.847mm; the optical material is H-ZLAF50E; the ninth lens 23 front and rear curvature radii are -18.495mm and -10.207mm; the optical thickness is -12.806mm; the optical material is H-ZLAF68B, wherein Table 2 shows the specific parameters of each optical element

[0040] Table 2

[0041]

[0042]

[0043] In this embodiment, the tenth lens 24 has a front and rear curvature radius of 172.849 mm and -544.359 mm; an optical thickness of 9.913 mm; and an optical material of GERMANIUM; the eleventh lens 25 has a front and rear curvature radius of 31.793 mm and 21.822 mm; an optical thickness of 3.690 mm; and an optical material of GERMANIUM; the twelfth lens 26 has a front and rear curvature radius of 24.898 mm and 37.129 mm; an optical thickness of 3.037 mm; and an optical material of ZNSE; the thirteenth lens 27 The front and rear curvature radii are -9.074mm and -18.018mm; the optical thickness is 8.292mm; the optical material is GERMANIUM; the front and rear curvature radii of the fourteenth lens 28 are 26.032mm and -94.834mm; the optical thickness is 8.008mm; the optical material is IRG206; the front and rear curvature radii of the fifteenth lens 29 are -124.906mm and -273.541mm; the optical thickness is 14.408mm; the optical material is ZNS-BROAD, wherein Table 3 shows the specific parameters of each optical component.

[0044] Table 3

[0045]

[0046]

[0047] from Figure 5 It can be seen that the system has an extremely high MTF response in the central field of view (0.0000 degrees), and the low-frequency part is close to the ideal value (MTF≈1.0), indicating that the system has good contrast transmission capabilities for large-scale targets. As the field of view angle increases (such as 0.1500 degrees), the MTF response gradually decreases, mainly subject to edge aberrations such as field curvature and astigmatism. There are certain differences in the MTF curves in the Sagittal (meridian) and Tangential (tangential) directions, indicating that the system has optimized astigmatism within the full field of view, but there is still a slight residue at a large field of view. Overall, the optical system still has significant imaging capabilities for spatial frequencies of up to 39 cycles / mm at a wavelength of 532nm, verifying that it has good performance in imaging resolution and contrast retention, meeting the design requirements of high-performance imaging applications.

[0048] like Figure 6As shown, in order to further evaluate the imaging quality of the optical system under different fields of view, a spot diagram based on a wavelength of 532nm is drawn. The figure shows the distribution of the light spot from the field of view of 0.0000° to 0.1500° on the object side. The figure is the image plane and the unit is mm. The spot diagram of the central field of view (0.0000°) is approximately circular, and the light spot is compact, indicating that the system has excellent imaging performance near the optical axis. As the field of view angle increases, the spot gradually deviates from the axis and produces a certain degree of asymmetric expansion, reflecting the increase in aberration effects at the edge of the field of view, mainly including coma, astigmatism, and field curvature. Especially at ±0.1500° on the object side, the light spot shows obvious stretching, dispersion, and even double peaks. This structure shows that the imaging quality of the system is significantly reduced at extreme field angles, and its edge performance limitations need to be paid attention to in actual use. From the RMS (root mean square radius) and GEO (geometric mean radius) values ​​listed below the figure, it can be seen that the RMS of the central spot (point 1) is only 15.134μm, while the edge (point 10) reaches 17.984μm, and the geometric mean even rises to 49.186μm, confirming the influence of edge aberration. In addition, the spot under each field of view angle contains multiple wavefront sample points, indicating that the simulation takes into account the beam distribution under the actual entrance pupil. Overall, the system has good focusing performance in the center and middle fields of view, and the changes in the edge spot reveal the boundary characteristics of the system's imaging range.

[0049] Figure 7 The figure shows the modulation transfer function (MTF) curve of the optical system in the wavelength range of 550nm to 750nm, which is used to evaluate the chromatic aberration control and overall imaging performance of the system under wide-band imaging conditions. The figure includes the MTF performance in the meridian and tangential directions at multiple angles from the center of the optical axis (0.0000°) to the edge of the field of view (0.7500°). In the entire spatial frequency range, the MTF curves at each field of view angle show a stable and smooth downward trend, and the MTF of the central field of view still maintains a high value (close to 0.7) in the high-frequency region, indicating that the system has good resolution of high spatial frequency details. Although the edge field of view has a certain decline, it still maintains an MTF value of more than 0.4 below 54.6 cycles / mm, indicating that the system has excellent full-field imaging consistency. In addition, the difference in the MTF curves between the wavelengths is small, indicating that the system has effectively controlled both on-axis and off-axis chromatic aberrations and has good multi-wavelength imaging capabilities. This feature makes it particularly suitable for multi-band laser imaging, polychromatic illumination detection or wide-spectrum imaging systems.

[0050] Figure 8The figure shows the spot diagram generated by the optical system at a wavelength of 532nm, which is used to demonstrate the imaging focusing ability and aberration performance under different field of view angles. The figure shows the distribution of the light spot at 10 typical viewing angles from 0.0000° to ±0.1500° in the object field of view. The image plane position has been corrected for aberrations and represents the final imaging position of the system. At the center of the optical axis (0.0000°), the light spot is approximately circular and highly concentrated, indicating that the system has excellent imaging sharpness and minimal wavefront distortion in the axial direction. As the field of view angle increases, the light spot gradually shows a tendency to stretch, deform or diffuse, especially at a viewing angle of ±0.1500°, the light spot shows typical coma and astigmatism characteristics, reflecting the cumulative effect of non-axial aberrations. The RMS radius and geometric mean radius (GEO Radius) in the table further quantify the changes in imaging quality. The RMS of the center field point (point 1) is 15.135μm, while the RMS of the edge field point (point 10) is 17.984μm. The geometric radius also increases accordingly, indicating that the system still maintains acceptable imaging performance in the edge imaging area and has good full field of view consistency.

[0051] like Fig. 9 As shown in the figure, the modulation transfer function (MTF) curve of the optical system in the wavelength range of 8.500μm to 13.500μm shows the imaging performance of the system in the mid-infrared band. The figure lists the MTF performance in the meridian and tangential directions of multiple field points from the center of the optical axis (0.0000°) to the maximum field of view (±1.3181°). Overall, the MTF curve of the system in each field of view has a steady downward trend, and still maintains a high OTF modulus value (about 0.5 to 0.6) when the spatial frequency reaches 20 cycles / mm, indicating that it has good high-frequency detail resolution capabilities in mid- and far-infrared imaging applications. The MTF is the highest in the central field of view. Although the edge field of view decreases slightly, the curve converges and is consistent, reflecting the system's full-field imaging uniformity and chromatic aberration control capabilities. This type of performance is particularly critical for mid-infrared imaging systems, such as thermal imaging, infrared detection and remote sensing applications, which place higher requirements on detail resolution and band adaptability. This system effectively controls chromatic aberration and image aberration by optimizing the band coverage design, ensuring stable imaging quality under multi-band conditions.

[0052] Fig.10The figure shows the spot diagram of the optical system at multiple field angles (from 0.0000° to ±1.3181° on the object side) on the image plane at a wavelength of 13.5μm. Each figure shows the expansion morphology of the imaging spot at the corresponding field point, which is used to intuitively evaluate the focusing ability and aberration control level of the system in the mid-infrared band. The spot in the central field of view (0.0000°) presents a regular and symmetrical diamond structure with a compact size, indicating that the system has good focusing accuracy and minimum aberration in the axial direction. As the field angle increases, especially at ±1.3181°, the spot gradually shows asymmetric expansion, edge stretching and composite structure, reflecting the appearance of typical edge aberrations such as coma and field curvature. The RMS radius listed in the table is only 12.367μm at the center point, while the maximum field of view (point 10) rises to 16.652μm, and the geometric radius (GEO) also increases accordingly, indicating that although the edge aberration has increased, the system as a whole still maintains a relatively high imaging quality range, which is particularly suitable for mid-infrared imaging application scenarios such as infrared remote sensing, thermal imaging, and large field of view detection.

[0053] Therefore, the present invention adopts the above-mentioned three-mode composite optical system. The system shares a secondary reflector and a primary reflector, and uses two beam splitters for light splitting, so that the system is applicable to laser, visible light and long-wave infrared light. While ensuring the quality of optical imaging, the system size is reduced, the cost is reduced, and the application range is wide.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A three-mode composite optical system, characterized in that: It includes an object plane, a primary reflector, a secondary reflector, a first beam splitter, a second beam splitter, a laser system, a visible light system and a long-wave infrared system; The light emitted from the object surface is reflected by the secondary reflector and the primary reflector to the first beam splitter, and then transmitted to the second beam splitter. After the light path is reflected by the second beam splitter, a laser system is formed. The light emitted from the object surface is reflected by the secondary reflector and the primary reflector to the first beam splitter, and passes through the reflected light path of the first beam splitter to form a visible light system; The light emitted from the object surface is reflected by the secondary reflector and the primary reflector to the first beam splitter, reaches the second beam splitter through the transmission effect of the first beam splitter, and passes through the transmission light path on the second beam splitter to form a long-wave infrared system.

2. A three-mode composite optical system according to claim 1, characterized in that: The laser system includes a first lens group, a first filter and a first detector; the light beam reflected on the second beam splitter passes through the first lens group and the first filter and is received by the first detector; wherein the first lens group includes a first lens, a second lens and a third lens which are sequentially arranged away from the second beam splitter.

3. A three-mode composite optical system according to claim 2, characterized in that: The front and rear curvature radii of the first lens range from 67mm to 97mm and 10mm to 40mm; the absolute value range of the optical thickness is 12mm to 15mm; the front and rear curvature radii of the second lens range from -35mm to -5mm and -64mm to -34mm; the absolute value range of the optical thickness is 3mm to 6mm; the front and rear curvature radii of the third lens range from -5mm to 25mm and -3mm to 27mm; the absolute value range of the optical thickness is 4mm to 7mm.

4. A three-mode composite optical system according to claim 3, characterized in that: The visible light system includes a second lens group, a second filter and a second detector; the light beam reflected by the first beam splitter passes through the second lens group and the second filter and is received by the second detector; wherein the second lens group includes a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens which are sequentially arranged away from the first beam splitter.

5. A three-mode composite optical system according to claim 4, characterized in that: The front and rear curvature radius of the fourth lens ranges from -74mm to -44mm and 69mm to 99mm; the absolute value range of optical thickness is 6mm to 9mm; the front and rear curvature radius of the fifth lens ranges from -32mm to -2mm and -87mm to -57mm; the absolute value range of optical thickness is 3mm to 6mm; the front and rear curvature radius of the sixth lens ranges from 1mm to 31mm and -51mm to -21mm; the absolute value range of optical thickness is 2mm to 5mm; the front and rear curvature radius of the seventh lens ranges from 95mm to 125mm and 3mm to 33mm; the absolute value range of optical thickness is 3mm to 6mm; the front and rear curvature radius of the eighth lens ranges from -91mm to -61mm and 44mm to 74mm; the absolute value range of optical thickness is 3mm to 6mm; the front and rear curvature radius of the ninth lens ranges from -33mm to -3mm and 44mm to 74mm; the absolute value range of optical thickness is 12mm to 15mm.

6. A three-mode composite optical system according to claim 5, characterized in that: The long-wave infrared system includes a third lens group, a third filter and a third detector; the light beam transmitted on the second beam splitter passes through the third lens group and the third filter and is received by the third detector; wherein the third lens group includes a tenth lens, an eleventh lens, a twelfth lens, a thirteenth lens, a fourteenth lens and a fifteenth lens which are sequentially arranged away from the second beam splitter.

7. A three-mode composite optical system according to claim 6, characterized in that: The front and rear curvature radii of the tenth lens range from 158mm to 188mm and -559mm to -529mm; the absolute value range of optical thickness is 8mm to 11mm; the front and rear curvature radii of the eleventh lens range from 17mm to 47mm and 7mm to 37mm; the absolute value range of optical thickness is 2mm to 5mm; the front and rear curvature radii of the twelfth lens range from 10mm to 40mm and 22mm to 52mm; the absolute value range of optical thickness is 2mm to 5mm; the front and rear curvature radii of the thirteenth lens range from -24mm to 6mm and -33mm to -3mm; the absolute value range of optical thickness is 7mm to 10mm; the front and rear curvature radii of the fourteenth lens range from 11mm to 41mm and -110mm to -80mm; the absolute value range of optical thickness is 7mm to 10mm; the front and rear curvature radii of the fifteenth lens range from -140mm to -110mm and -289mm to -259mm; the absolute value range of optical thickness is 13mm to 16mm.

Images