A cold atom high-resolution imaging microscope objective

Abstract

The present invention discloses 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 is composed of two lenses of a meniscus lens, the intermediate negative lens group is composed of a lens of a meniscus lens, a lens of a biconvex lens and a cemented lens consisting of a biconvex lens and a meniscus lens, and the rear positive lens group is composed of a cemented 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 lens of the present invention has the advantages of a large numerical aperture and a long working distance, can effectively compensate for the aberration introduced by the vacuum window, and realize submicron-level high-resolution imaging.

Description

Technical Field

[0001] The present 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 methods for cold atom gas experiments. It enables single-point detection and manipulation of cold atomic gases, playing a vital role in the study of physical phenomena such as high-temperature superconductivity, giant magnetoresistance, and quantum magnetism. Microscope objectives are a crucial component of cold atom high-resolution imaging systems, enabling 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 target of a traditional microscope objective is 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 high-resolution cold atom imaging experiment has high requirements for 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 long working distance. The optical design of a microscope objective with a long working distance and a large numerical aperture is more 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 aberrations of the vacuum window. However, commercial microscope systems have problems such as a short working distance and an inability to compensate for the aberrations introduced into the imaging system by the vacuum window, which cannot meet the requirements of high-resolution cold atom imaging. Summary of the Invention

[0005] In response to the above-mentioned 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, and achieve submicron-level 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 chamber; the front negative lens group consists of a first lens and a second lens of a meniscus lens; the intermediate negative lens group consists of a third lens of a meniscus lens, a fourth lens of a biconvex lens and a cemented lens first consisting of a biconvex lens and a meniscus lens; the rear positive lens group consists of a second cemented 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.

[0007] The cold atom high-resolution imaging microscope objective lens has a distance between lens 1 and lens 2 of 3.7±0.03 mm; a distance between lens 2 and lens 3 of 26.27±0.03 mm; a distance between lens 3 and lens 4 of 4.6±0.03 mm; a distance between lens 4 and cemented lens 1 of 0.3±0.03 mm; a distance between cemented lens 1 and cemented lens 2 of 3.51±0.03 mm; a distance between cemented lens 2 and rear lens group 1 of 0.3±0.03 mm; a distance between rear lens group 1 and rear lens group 2 of 0.3±0.03 mm; a distance between rear lens group 2 and rear lens group 3 of 0.3±0.03 mm; and a distance between rear lens group 3 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±4 mm; a focal length of lens two of -59.75±4 mm; a focal length of lens three of -102.13±4 mm; a focal length of lens four of 73.69±4 mm; a focal length of cemented lens one of 148.87±4 mm; a focal length of cemented lens two of -64.02±4 mm; a focal length of rear lens group one of 57.21±4 mm; a focal length of rear lens group two of 77.03±4 mm; and a focal length of rear lens group three of 62.89±4 mm.

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

[0010] The described 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 microscope objective lens operates in a wavelength range of 399 to 759 nm, has a numerical aperture of 0.6, a working distance of 15 mm, and a total optical system length of 114.96 mm. According to the Rayleigh criterion, the microscope objective lens has a resolution better than 0.6 μm, enabling submicron-level high-resolution imaging. The scope of cold atom clusters observable by the microscope is 400 μm x 400 μm.

[0011] The beneficial effects produced by the present invention are:

[0012] 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 negative optical focal length, which is conducive to increasing the working distance; the middle lens group consists of two single lenses and a cemented lens, which has negative weak optical focal length and mainly corrects complex aberrations caused by a wide spectrum and a large numerical aperture; the rear lens group has positive optical focal length and is composed of a cemented lens and three single lenses. It bears the main optical focal length of the system, and effectively compensates for various aberrations of the system through a complex design.

[0013] 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 aberrations, and the imaging quality is close to the diffraction limit. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the optical path of an embodiment of the present invention;

[0015] Figure 2 is an optical structure diagram of an embodiment of the present invention;

[0016] Figure 3 This is an MTF diagram of an embodiment of the present invention;

[0017] Figure 4 is a spot diagram of an embodiment of the present invention;

[0018] Figure 5 This is an energy concentration diagram of an embodiment of the present invention;

[0019] Figure 6 2 is a diagram of light aberration according to an embodiment of the present invention.

[0020] 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

[0021] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to 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 intended to limit the present invention.

[0022] 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, 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 cavity.

[0023] The front negative lens group consists of a meniscus lens (lens 1) and a lens 2 (lens 2). The front negative lens group has a negative optical power to increase the working distance of the microscope objective. 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.

[0024] The intermediate negative lens group consists of lens three 3 of a meniscus lens, lens four 4 of a biconvex lens, and a cemented lens one 5 composed of a biconvex 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 large numerical aperture, wherein the distance between lens two 2 and lens three 3 is 26.24-26.3mm, the distance between lens three 3 and lens four 4 is 4.57-4.63mm, the distance between lens four 4 and cemented lens one 5 is 0.27-0.33mm, the distance between cemented lens one 5 and cemented lens two 6 is 3.48-3.54mm, the focal length of lens three 3 is -106.13--98.13mm, the focal length of lens four 4 is 69.69-77.69mm, and the focal length of cemented lens one 5 is 144.87-152.87mm.

[0025] The rear positive lens group is composed of a cemented lens 2 (6) consisting of a biconcave lens and a biconvex lens, a rear lens group 1 (7) of a biconvex lens, a rear lens group 2 (8) of a biconvex lens, and a rear lens group 3 (9) of a meniscus lens. The rear positive lens group bears the main optical power of the system and effectively compensates for various aberrations of the system through a complex design. The distance between the cemented lens 2 (6) and the rear lens group 1 (7) is 0.3 to 0.3 mm, and the distance between the rear lens group 1 (7) and the rear lens group 2 (8) 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.

[0026] 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.

[0027] The low-dispersion calcium fluoride glass material used in lens 4, rear lens group 1 7, and rear lens group 2 8 of the present microscope objective lens effectively reduces chromatic aberration across a wide wavelength range and improves the imaging quality of the microscope objective lens. The lens material of the microscope objective lens has low absorption at the operating wavelength and is composed of HZLAF66GT, HLAK4L, HZBAF20, CAF2, HZLAF68C, and HZLAF53B.

[0028] The focal length of the microscope objective lens of the present invention is 28.5±4mm, and it can be used in conjunction 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.

[0029] In summary, the cold-atom high-resolution imaging microscope objective lens of the present invention, composed of seven single lenses and two cemented lenses, offers the advantages of a long working distance and a large numerical aperture. This effectively compensates for aberrations in the vacuum window, enabling high-resolution imaging of cold atoms within a vacuum chamber. The optical system utilizes lens materials with minimal absorption at the operating wavelength and employs a combination of high- and low-chromatic aberration glass to eliminate aberrations, resulting in imaging quality approaching the diffraction limit.

[0030] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such 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 by: From the object side to the image side, it 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 lens one (1) and lens two (2) of a meniscus lens; the intermediate negative lens group is composed of lens three (3) of a meniscus lens, lens four (4) of a biconvex lens and a cemented lens one (5) composed of a biconvex lens and a meniscus lens; the rear positive lens group is composed of cemented lens two (6) composed of a biconcave lens and a biconvex lens, rear lens one (7) of a biconvex lens, rear lens two (8) of a biconvex lens and rear lens three (9) of a meniscus lens, the distance between lens one (1) and lens two (2) is 3.7mm; the distance between lens two (2) and lens three (3) is 26.27mm; the distance between lens three (3) and lens four (4) is 4.6mm; the distance between lens four (4) and cemented lens one (5) is 0.3mm; the distance between the ... The distance between the combined lens 1 (5) and the cemented lens 2 (6) is 3.51 mm; the distance between the cemented lens 2 (6) and the rear lens 1 (7) is 0.3 mm; the distance between the rear lens 1 (7) and the rear lens 2 (8) is 0.3 mm; the distance between the rear lens 2 (8) and the rear lens 3 (9) is 0.3 mm; the distance between the rear lens 3 (9) and the vacuum window (10) is 4 mm, and the focal length of the lens 1 (1) is 78.09 mm; the lens The focal length of lens two (2) is -59.75mm; the focal length of lens three (3) is -102.13mm; the focal length of lens four (4) is 73.69mm; the focal length of cemented lens one (5) is 148.87mm; the focal length of cemented lens two (6) is -64.02mm; the focal length of rear lens one (7) is 57.21mm; the focal length of rear lens two (8) is 77.03mm, and the focal length of rear lens three (9) is 62.89mm.

2. The cold atom high-resolution imaging microscope objective lens according to claim 1, 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.

3. A cold atom high-resolution imaging microscope objective lens according to claim 1 or 2, characterized in that: The focal length of the microscope objective is 28.5 mm, the working band 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.

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