Cold atom high-resolution imaging microscope objective

Abstract

The invention discloses a cold atom high-resolution imaging microscope objective, which sequentially comprises a front negative lens group, a middle negative lens group, a rear positive lens group and a vacuum window on a vacuum cavity from an object space to an image space, the front negative lens group is composed of two lenses of a meniscus lens, and the middle negative lens group is composed of a lens of the meniscus lens, a lens of a biconvex lens and a balsaming lens composed of a biconvex lens and the meniscus lens. The rear positive lens group consists of a balsaming lens consisting of a biconcave lens and a biconvex lens, a rear lens group of the biconvex lens, a rear lens group of the biconvex lens and a rear lens group of the meniscus lens; the microscope objective has the advantages of large numerical aperture and long working distance, aberration introduced by a vacuum window can be effectively compensated, and submicron high-resolution imaging is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of cold atom optical imaging, and in particular relates to a cold atom high-resolution imaging microscope. Background Art

[0002] Cold atom high-resolution imaging technology provides precise and intuitive control means for cold atom gas experiments. It can detect and manipulate cold atom gases at single grid points, and plays an important role in the study of physical phenomena such as high-temperature superconductivity, giant magnetoresistance, and quantum magnetism. Microscope objective is an important component of cold atom high-resolution imaging system, which realizes high-resolution imaging of cold atoms.

[0003] The resolution of a microscope objective is inversely proportional to the numerical aperture of the microscope. The observation targets of traditional microscope objectives are basically in the air, so the working distance of the microscope can be shorter, and it is easier to obtain a microscope objective with a large numerical aperture. However, the cold atom high-resolution imaging experiment has high requirements on the vacuum degree of the vacuum system. The cold atoms to be observed are located in a vacuum cavity, and the microscope objective needs to have a longer working distance. The optical design of a microscope objective with a long working distance and a large numerical aperture is difficult. At the same time, in the cold atom imaging system, the cold atoms need to be imaged through a vacuum window. The vacuum window can be regarded as a parallel plate of glass material. For a microscope objective with a large numerical aperture, a thicker vacuum window will cause significant spherical aberration, reducing the resolution of the entire optical system.

[0004] Therefore, the microscope objective used in the cold atom high-resolution imaging system needs to have a large numerical aperture and a long working distance, and be able to correct the aberration of the vacuum window. However, commercial microscope systems have problems such as short working distance and inability to compensate for the aberration introduced into the imaging system by the vacuum window, and cannot meet the requirements of high-resolution imaging of cold atoms. Summary of the invention

[0005] In view of the above deficiencies in the prior art, the present invention provides a cold atom high-resolution imaging microscope objective lens, which has the advantages of large numerical aperture and long working distance, can effectively compensate for the aberration of the vacuum window, realize submicron high-resolution imaging, and can be applied to the field of cold atom high-resolution imaging.

[0006] The technical solution adopted by the present invention to solve its technical problems is: a cold atom high-resolution imaging microscope objective lens, which comprises, from the object side to the image side, a front negative lens group, an intermediate negative lens group, a rear positive lens group and a vacuum window on a vacuum cavity; the front negative lens group consists of a lens 1 and a lens 2 of a meniscus lens; the intermediate negative lens group consists of a lens 3 of a meniscus lens, a lens 4 of a biconvex lens and a cemented lens 1 consisting of a biconvex lens and a meniscus lens; the rear positive lens group consists of a cemented lens 2 consisting of a biconcave lens and a biconvex lens, a rear lens 1 of the biconvex lens, a rear lens 2 of the biconvex lens and a rear lens 3 of the meniscus lens.

[0007] The cold atom high-resolution imaging microscope objective lens has a distance between lens one and lens two of 3.7±0.03 mm; a distance between lens two and lens three of 26.27±0.03 mm; a distance between lens three and lens four of 4.6±0.03 mm; a distance between lens four and cemented lens one of 0.3±0.03 mm; a distance between cemented lens one and cemented lens two of 3.51±0.03 mm; a distance between cemented lens two and rear lens one of 0.3±0.03 mm; a distance between rear lens one and rear lens two of 0.3±0.03 mm; a distance between rear lens two and rear lens three of 0.3±0.03 mm; and a distance between rear lens three and the vacuum window of 4±0.03 mm.

[0008] The cold atom high-resolution imaging microscope objective lens has a focal length of lens one of 78.09±4mm, a focal length of lens two of -59.75±4mm, a focal length of lens three of -102.13±4mm, a focal length of lens four of 73.69±4mm, a focal length of cemented lens one of 148.87±4mm, a focal length of cemented lens two of -64.02±4mm, a focal length of rear lens one of 57.21±4mm, a focal length of rear lens two of 77.03±4mm, and a focal length of rear lens three of 62.89±4mm.

[0009] The cold atom high-resolution imaging microscope objective lens, wherein lens 4, rear lens group 1 and rear lens group 2 all adopt low-dispersion glass material calcium fluoride, can effectively reduce chromatic aberration in a wide band and improve the imaging quality of the microscope objective lens; the material of the vacuum window is quartz glass with a thickness of 3.5 mm.

[0010] The cold atom high-resolution imaging microscope objective lens has a focal length of 28.5 mm and can be used with a commercial eyepiece to achieve magnified imaging. The working band of the microscope objective lens is 399 to 759 nm, the numerical aperture is 0.6, the working distance is 15 mm, and the total length of the optical system is 114.96 mm. According to the Rayleigh criterion, the resolution of the microscope objective lens is better than 0.6 μm, and submicron-level high-resolution imaging can be achieved. The range of cold atomic clusters that can be observed by the microscope objective lens is 400 μm×400 μm.

[0011] The beneficial effects produced by the present invention are: The microscope objective lens of the present invention is an infinite conjugate microscope objective lens, which adopts a "negative-negative-positive" structural type: the front lens group consists of two single lenses and has a negative optical focal length, which is beneficial to increasing the working distance; the middle lens group consists of two single lenses and a cemented lens, which has a negative weak optical focal length and is mainly used to correct complex aberrations caused by a wide spectrum and a large numerical aperture; the rear lens group has a positive optical focal length, which bears the main optical focal length of the system and is composed of a cemented lens and three single lenses, and effectively compensates for various aberrations of the system through a complex design.

[0012] The present invention has the advantages of long working distance and large numerical aperture, can effectively compensate for the aberration of the vacuum window, and realize high-resolution imaging of cold atoms in the vacuum cavity; the optical system adopts lens materials with less absorption of the working wavelength, and adopts a combination of high and low chromatic aberration glass to eliminate aberration, and the imaging quality is close to the diffraction limit. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a principle diagram of an optical path of an embodiment of the present invention; Figure 2 is an optical structure diagram of an embodiment of the present invention; Figure 3 is an MTF diagram of an embodiment of the present invention; Figure 4 is a point diagram of an embodiment of the present invention; Figure 5 An energy concentration diagram of an embodiment of the present invention; Figure 6 2 is a light aberration diagram of an embodiment of the present invention.

[0014] The figures are marked as follows: 1—lens one, 2—lens two, 3—lens three, 4—lens four, 5—cemented lens one, 6—cemented lens two, 7—rear group lens one, 8—rear group lens two, 9—rear group lens three, 10—vacuum window, 11—imaging cold atom. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0016] like Figure 1 and Figure 2 As shown, a cold atom high-resolution imaging microscope objective lens disclosed in an embodiment of the present invention adopts a "negative-negative-positive" optical focal length combination form, and includes, from the object side to the image side, a front negative lens group, a middle negative lens group, a rear positive lens group and a vacuum window 10 on the vacuum chamber.

[0017] The front negative lens group is composed of a meniscus lens lens 1 and a lens 2; the front negative lens group has a negative focal length to increase the working distance of the microscope objective lens. The distance between lens 1 and lens 2 is 3.67 to 3.73 mm, the focal length of lens 1 is 74.09 to 82.09 mm, and the focal length of lens 2 is -63.75 to -55.75 mm.

[0018] The intermediate negative lens group is composed of lens three 3 of a meniscus lens, lens four 4 of a double convex lens, and a cemented lens one 5 composed of a double convex lens and a meniscus lens; the intermediate negative lens group has negative weak light focal length, mainly correcting complex aberrations caused by a wide spectrum and a large numerical aperture, wherein the distance between lens two 2 and lens three 3 is 26.24-26.3 mm, the distance between lens three 3 and lens four 4 is 4.57-4.63 mm, the distance between lens four 4 and cemented lens one 5 is 0.27-0.33 mm, the distance between cemented lens one 5 and cemented lens two 6 is 3.48-3.54 mm, the focal length of lens three 3 is -106.13--98.13 mm, the focal length of lens four 4 is 69.69-77.69 mm, and the focal length of cemented lens one 5 is 144.87-152.87 mm.

[0019] The rear positive lens group is composed of a cemented lens 26 composed of a double concave lens and a double convex lens, a rear lens 17 of a double convex lens, a rear lens 28 of a double convex lens and a rear lens 39 of a meniscus lens. The rear positive lens group bears the main optical focal length of the system and effectively compensates for various aberrations of the system through a complex design. The distance between the cemented lens 26 and the rear lens 17 is 0.3 to 0.3 mm, and the distance between the rear lens 17 and the rear lens 28 is 0.27 to 0.33 m. m, the distance between the rear lens group 2 8 and the rear lens group 3 9 is 0.27-0.33 mm, the distance between the rear lens group 3 9 and the vacuum window 10 is 3.97-4.03 mm, the focal length of the cemented lens 2 6 is -68.02--60.02 mm, the focal length of the rear lens group 1 7 is 53.21-61.21 mm, the focal length of the rear lens group 2 8 is 73.03-81.03 mm, and the focal length of the rear lens group 3 9 is 58.89-66.89 mm.

[0020] The microscope objective lens of the present invention is an infinite conjugate microscope objective lens, which can compensate for the aberration introduced by the vacuum window 10 and realize high-resolution imaging of the cold atoms in the vacuum cavity through the vacuum window 10. The material of the vacuum window 10 is quartz glass with a thickness of 3.5 mm. The distance between the imaging cold atom 11 and the vacuum window 10 is 11.5 mm.

[0021] The lens 44, the rear lens 17 and the rear lens 28 of the microscope objective lens of the present invention all adopt the low dispersion glass material calcium fluoride, which can effectively reduce the chromatic aberration of a wide band and improve the imaging quality of the microscope objective lens. The lens material of the microscope objective lens has low absorption of the working wavelength, and the lens material is composed of HZLAF66GT, HLAK4L, HZBAF20, CAF2, HZLAF68C and HZLAF53B.

[0022] The focal length of the microscope objective lens of the present invention is 28.5±4mm, and it can be used in combination with a commercial eyepiece to achieve magnified imaging. The working band of the microscope objective lens is 399-759nm, the numerical aperture is 0.6, the working distance is 15mm, and the total length of the optical system is 114.96mm. According to the Rayleigh criterion, the resolution of the microscope objective lens is better than 0.6μm, and submicron high-resolution imaging can be achieved. The range of cold atomic clusters that can be observed by the microscope objective lens is 400μm×400μm. The MTF diagram of the embodiment of the present invention is as follows: Figure 3 As shown, the point diagram is as follows Figure 4 As shown in the energy concentration diagram, Figure 5 As shown, the light aberration diagram is as follows Figure 6 shown.

[0023] In summary, the cold atom high-resolution imaging microscope objective lens of the present invention is composed of 7 single lenses and 2 cemented lenses, and has the advantages of long working distance and large numerical aperture, and can effectively compensate for the aberration of the vacuum window, and realize high-resolution imaging of cold atoms in the vacuum cavity. The optical system uses lens materials with less absorption of the working wavelength, and uses a combination of high and low chromatic aberration glasses to eliminate aberrations, and the imaging quality is close to the diffraction limit.

[0024] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A cold atom high-resolution imaging microscope objective lens, characterized in that: From the object side to the image side, the lens system includes a front negative lens group, an intermediate negative lens group, a rear positive lens group and a vacuum window (10) on the vacuum chamber; the front negative lens group is composed of a meniscus lens lens 1 (1) and a lens 2 (2); the intermediate negative lens group is composed of a meniscus lens lens 3 (3), a biconvex lens lens 4 (4) and a cemented lens 1 (5) composed of a biconvex lens and a meniscus lens; the rear positive lens group is composed of a cemented lens 2 (6) composed of a biconcave lens and a biconvex lens, a rear lens 1 (7) of a biconvex lens, a rear lens 2 (8) of a biconvex lens and a rear lens 3 (9) of a meniscus lens.

2. The cold atom high-resolution imaging microscope objective lens according to claim 1, characterized in that: The distance between the lens 1 (1) and the lens 2 (2) is 3.7±0.03mm; the distance between the lens 2 (2) and the lens 3 (3) is 26.27±0.03mm; the distance between the lens 3 (3) and the lens 4 (4) is 4.6±0.03mm; the distance between the lens 4 (4) and the cemented lens 1 (5) is 0.3±0.03mm; the distance between the cemented lens 1 (5) and the cemented lens 2 (6) is 3.51±0.03mm; the distance between the cemented lens 2 (6) and the rear lens 1 (7) is 0.3±0.03mm; the distance between the rear lens 1 (7) and the rear lens 2 (8) is 0.3±0.03mm; the distance between the rear lens 2 (8) and the rear lens 3 (9) is 0.3±0.03mm; and the distance between the rear lens 3 (9) and the vacuum window (10) is 4±0.03mm.

3. The cold atom high-resolution imaging microscope objective lens according to claim 2, characterized in that: The focal length of the lens one (1) is 78.09±4mm; the focal length of the lens two (2) is -59.75±4mm; the focal length of the lens three (3) is -102.13±4mm; the focal length of the lens four (4) is 73.69±4mm; the focal length of the cemented lens one (5) is 148.87±4mm; the focal length of the cemented lens two (6) is -64.02±4mm; the focal length of the rear lens one (7) is 57.21±4mm; the focal length of the rear lens two (8) is 77.03±4mm, and the focal length of the rear lens three (9) is 62.89±4mm.

4. A cold atom high-resolution imaging microscope objective lens according to claim 1, 2 or 3, characterized in that: The lens four (4), the rear lens group one (7) and the rear lens group two (8) are all made of calcium fluoride, and the material of the vacuum window (10) is quartz glass with a thickness of 3.5 mm.

5. A cold atom high-resolution imaging microscope objective lens according to claim 1, 2, 3 or 4, characterized in that: The focal length of the microscope objective is 28.5 mm, the working band is 399-759 nm, the numerical aperture is 0.6, the working distance is 15 mm, and the total length of the optical system is 114.96 mm.

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