Ultrahigh vacuum optical fiber feed-through integrated with light beam focusing function

Abstract

The utility model discloses an ultrahigh vacuum optical fiber feed-through integrated with a light beam focusing function, which comprises a vacuum flange plate, a lens mounting cylinder and an optical fiber head mounting seat, and is characterized in that a light beam is guided into an ultrahigh vacuum cavity through an optical fiber and is directly input through an optical fiber slot on the flange plate; the stability of an optical path can be well guaranteed, and meanwhile, great convenience is brought to equipment movement; in addition, the required laser beam enters the cavity through the optical fiber port, so that excessive light exposure windows do not exist, and the background brought by spatial light can be greatly reduced. A collimating lens group is further arranged in the optical fiber head mounting seat, a focusing lens is arranged in the lens mounting barrel, a position adjusting mechanism is further arranged, and the diameter of a light spot can be changed by adjusting the distance between the collimating lens group and the focusing lens.

Description

An ultra-high vacuum fiber feedthrough with integrated beam focusing function Technical Field

[0001] This utility model belongs to the field of vacuum device technology, specifically relating to an ultra-high vacuum fiber feedthrough with integrated beam focusing function. Background Technology

[0002] In scientific research, it is often necessary to input laser beams into a vacuum environment. A common method is for a free-space laser beam to be directly introduced into the vacuum environment through a glass window. Particularly in atomic, molecular, and optical physics research, researchers often need to prepare atomic or ionic samples in an ultra-high vacuum environment and then use lasers to act on the samples for scientific research. Correspondingly, ultra-high vacuum cavities often require multiple glass windows to allow light transmission, and researchers need to introduce a pre-tuned laser beam from free space into the ultra-high vacuum cavity through these windows. However, this method of light transmission has some problems:

[0003] (1) The laser beam in free space is relatively independent of the ultra-high vacuum cavity where the sample is located, and it is difficult to guarantee the stability of the optical path. In particular, when the equipment needs to be moved, the optical path needs to be readjusted and optimized.

[0004] (2) Free space beams enter the vacuum cavity through a large glass window, but excessive light exposure also allows ambient light beams to enter the sample space more easily, resulting in a relatively large light background, which has an adverse effect on some experiments.

[0005] (3) Traditional free light enters the cavity through a glass window, and the existing flange fiber coupling design makes it difficult to adjust the divergence angle and laser spot size after the laser enters the cavity. In addition, in many studies that require high power density, the laser that is traditionally focused by a lens outside the cavity is limited by the distance from the lens to the cavity center, which cannot be smaller, so the focused spot is difficult to reach the level of several micrometers. Summary of the Invention

[0006] The purpose of this invention is to address the aforementioned problems in the existing technology by providing an ultra-high vacuum fiber feedthrough with integrated beam focusing function.

[0007] The above-mentioned objectives of this utility model are achieved through the following technical means:

[0008] An ultra-high vacuum fiber optic feedthrough with integrated beam focusing function includes a vacuum flange, a lens mounting cylinder, and a fiber optic head mounting base. A mounting groove is provided at the center of one side of the vacuum flange, the front end of the fiber optic head mounting base is located in the mounting groove, and a fiber optic head socket is provided at the rear end of the mounting groove. The lens mounting cylinder is located on the other side of the vacuum flange and is equipped with a focusing lens.

[0009] As described above, the fiber optic connector mounting base is also equipped with a collimating lens group, which is located in front of the fiber optic connector socket, and a light-transmitting hole is provided between the fiber optic connector socket and the collimating lens group.

[0010] It also includes an optical fiber adjustment mechanism, which includes multiple sets of set wires, each set of set wires including two set wires arranged in the same direction and opposite to each other; the optical fiber head mounting base is also provided with multiple sets of adjustment holes, each set of adjustment holes including two adjustment holes in the same direction, the two adjustment holes of each set of adjustment holes are respectively distributed on both sides of the optical fiber head socket and connected, the adjustment holes are perpendicular to the optical fiber socket, multiple pairs of adjustment threaded holes are evenly distributed along the circumferential direction of the optical fiber head mounting base, the two set wires of each set of set wires are respectively adapted and connected to the two adjustment holes of the corresponding set of adjustment holes, one end of the set wire is inserted into the adjustment hole, and the other end of the set wire is provided with an adjustment knob.

[0011] As described above, the set screw has an external thread, and the adjustment hole has an internal thread that matches the external thread of the set screw. The set screw is screwed into the corresponding adjustment hole until it abuts against the fiber optic head.

[0012] As described above, the bottom of the mounting slot has a window mounting hole that penetrates the vacuum flange, and a sealing window is provided in the window mounting hole.

[0013] As mentioned above, the lens mounting cylinder is also equipped with an exhaust port.

[0014] It also includes a focusing lens position adjustment mechanism, which includes a first fixing ring and a second fixing ring. The lens mounting cylinder is provided with an internal thread, and both the first fixing ring and the second fixing ring are provided with external threads that are adapted to the internal threads of the lens mounting cylinder. The focusing lens is disposed between the first fixing ring and the second fixing ring.

[0015] As mentioned above, the fiber optic connector is also equipped with a fiber optic head fixing clip.

[0016] As described above, the fiber optic connector, light-transmitting hole, collimating lens group, sealing window, and focusing lens all share a common central axis.

[0017] Compared with the prior art, this utility model has the following advantages:

[0018] (1) The beam of this utility model is guided into the ultra-high vacuum cavity through optical fiber. The beam is directly input through the optical fiber slot on the flange, which can ensure the stability of the optical path and also bring great convenience to the movement of the equipment. In addition, since the laser beam we need enters the high vacuum cavity through the optical fiber port, there are no excessive light exposure windows, which can also greatly reduce the background caused by spatial light.

[0019] (2) The present invention is also provided with a collimating lens group and a focusing lens, and a focusing lens position adjustment mechanism is provided, which can change the spot diameter by adjusting the distance between the collimating lens group and the focusing lens. Attached Figure Description

[0020] Figure 1 is a cross-sectional view of the device of this utility model;

[0021] Figure 2 is a front view of the device of this utility model viewed axially from the focusing lens side;

[0022] Figure 3 is a front view of the device of this utility model after it is connected to the optical fiber;

[0023] Figure 4 is a front view of the device of this utility model viewed axially from the fiber optic mounting base side;

[0024] Figure labels and corresponding component names:

[0025] 1-Focusing lens; 2-Sealed window; 3-Vacuum flange; 4-Collimating lens group; 5-Mounting groove; 6-Fiber optic head mounting base; 7-Fiber optic head socket; 8-Fiber optic head fixing buckle; 9-Light passage hole; 10-Top screw; 11-First fixing ring; 12-Lens mounting cylinder; 13-Second fixing ring; 14-Exhaust port. Detailed Implementation

[0026] To facilitate understanding and implementation of this utility model by those skilled in the art, the present utility model will be further described in detail below with reference to embodiments. The embodiments described herein are only for illustration and explanation and are not intended to limit the present utility model.

[0027] Example 1:

[0028] An ultra-high vacuum fiber optic feedthrough with integrated beam focusing function includes a vacuum flange 3, a lens mounting cylinder 12, and a fiber optic head mounting base 6. A mounting groove 5 is provided at the center of one side of the vacuum flange 3. The front end of the fiber optic head mounting base 6 is located in the mounting groove 5, and a fiber optic head socket 7 is provided at the rear end of the mounting groove 5. The lens mounting cylinder 12 is located on the other side of the vacuum flange 3, and a focusing lens 1 is provided on the lens mounting cylinder 12.

[0029] The fiber optic head mounting base 6 is also provided with a collimating lens group 4, which is located in front of the fiber optic head socket 7. A light-transmitting hole 9 is provided between the fiber optic head socket 7 and the collimating lens group 4, and the light-transmitting hole 9 is directly aligned with the collimating lens group 4. After the fiber optic head is inserted into the fiber optic head socket 7, the light output from the fiber optic head passes through the light-transmitting hole 9 and reaches the collimating lens group 4.

[0030] As one possible implementation, the collimating lens group 4 can be a short focal length lens. Alternatively, strong adhesive can be used to fix the collimating lens group 4 to the fiber optic head mounting base 6. The collimating lens group 4 can be adjusted to make the laser beam parallel, which is used to convert the light emitted from the fiber optic head into a parallel beam. The parallel beam is transmitted through the quartz window to the focusing lens 1.

[0031] The bottom of the mounting slot 5 is provided with a window mounting hole that penetrates the vacuum flange 3. A sealing window 2 is provided in the window mounting hole. The parallel beam converted by the collimating lens group 4 is then transmitted to the focusing lens 1 through the sealing window 2.

[0032] As one possible implementation, the two sides of the sealing window 2 are respectively the atmospheric environment and the vacuum environment. Therefore, the sealing window 2 can be made of high-strength quartz window to separate the atmospheric environment and the vacuum environment.

[0033] It also includes an optical fiber adjustment mechanism, which comprises multiple sets of set wires, each set of set wires including two set wires 10 arranged in the same direction and opposite to each other; the optical fiber head mounting base 6 is also provided with multiple sets of adjustment holes, each set of adjustment holes including two adjustment holes along the same direction, the two adjustment holes of each set of adjustment holes are respectively distributed on both sides of the optical fiber head socket 7 and connected, the adjustment holes are perpendicular to the optical fiber socket (i.e. perpendicular to the axial direction of the optical fiber head mounting base 6), multiple pairs of adjustment threaded holes are evenly distributed along the circumferential direction of the optical fiber head mounting base 6, the two set wires 10 of each set of set wires are respectively adapted and connected to the two adjustment holes of the corresponding set of adjustment holes, wherein one end of the set wire 10 is inserted into the adjustment hole, and the other end of the set wire 10 is provided with an adjustment knob; the set wire 10 can ensure the stability of the beam direction of the optical fiber output;

[0034] As one possible implementation, the set screw 10 is provided with an external thread, and the adjustment hole is provided with an internal thread that matches the external thread of the set screw 10. The set screw 10 and the adjustment hole are connected by threads. The set screw 10 is screwed into the corresponding adjustment hole until it abuts against the fiber optic head. The two set screws 10 in the same set screw group can also be adjusted by adjusting the knob, which can realize the fine adjustment of the beam direction output by the fiber optic head.

[0035] The fiber optic connector 7 is also provided with a fiber optic connector fixing buckle 8. As one possible implementation, the fiber optic connector fixing buckle 8 is an opening on the outer periphery of the end of the fiber optic connector 7, which is used to accommodate the protrusion of the fiber optic connector, to hold the fiber optic connector in place, and to prevent the fiber optic connector from rotating.

[0036] It also includes a position adjustment mechanism for the focusing lens 1. The position adjustment mechanism includes a first fixing ring 11 and a second fixing ring 13. The lens mounting cylinder 12 is provided with an internal thread. The first fixing ring 11 and the second fixing ring 13 are both provided with external threads that are adapted to the internal threads of the lens mounting cylinder 12. The focusing lens 1 is disposed between the first fixing ring 11 and the second fixing ring 13.

[0037] An exhaust port 14 is also provided on the lens mounting tube 12.

[0038] In this embodiment, the vacuum flange 3 is made of a material suitable for ultra-high vacuum environments, such as stainless steel, but not limited to stainless steel. The connection between the vacuum flange 3 and the ultra-high vacuum cavity is provided on one side of the vacuum flange 3 with the lens mounting cylinder 12. The connection can be made by knife-edge connection and screw fastening. The parallel beam of light is focused by the focusing lens 1 and then enters the ultra-high vacuum cavity.

[0039] When installing the lens into the lens mounting cylinder 12, the first retaining ring 11, the focusing lens 1, and the second retaining ring 13 are inserted in sequence. When it is necessary to adjust the position of the focusing lens 1, the first retaining ring 11 and the second retaining ring 13 can be rotated at the exhaust port 14 to adjust the position of the focusing lens 1.

[0040] Fiber optic connector 7, light-transmitting hole 9, collimating lens group 4, sealing window 2, and focusing lens 1 are all on the same central axis.

[0041] By adjusting the position of the focusing lens 1, the distance between the focusing lens 1 and the collimating lens group 4 can be adjusted. The laser emitted from the focusing lens 1 can achieve different spot diameters depending on the distance, thereby achieving different focusing effects and realizing the laser beam expansion or contraction effect. The smallest spot size can be as small as a few micrometers.

[0042] Specifically, the diameter d of the laser spot at the focal point after laser focusing can be calculated using the following formula:

[0043] d=2f*λ / D (1)

[0044] Where f is the focal length of focusing lens 1, λ is the laser wavelength, and D is the beam waist diameter before laser focusing. Since focusing lens 1 is inside the ultra-high vacuum cavity, the focal length f is not limited by the size of the cavity. It can continuously approach the ion trap without affecting ion confinement. The beam expansion effect can be achieved by adjusting the distance between collimating lens group 4 and focusing lens 1, so that D reaches a diameter of several mm (e.g., 10 mm). Therefore, when the laser wavelength λ (e.g., 500 nm) is fixed, the focal length f is 50 mm, and the diameter d of the focused spot can reach 5 μm, which is much smaller than the spot diameter when focusing outside the cavity. The power density achieved at the same laser power is also greater. This can also be achieved by replacing focusing lens 1 with different focal lengths.

[0045] It should be noted that the embodiments described in this utility model are merely illustrative examples of the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described embodiments or use similar methods to replace them, but without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. An ultra-high vacuum fiber optic feedthrough with integrated beam focusing function, comprising a vacuum flange (3), characterized in that, It also includes a lens mounting cylinder (12) and an optical fiber head mounting base (6). A mounting groove (5) is provided at the center of one side of the vacuum flange (3). The front end of the optical fiber head mounting base (6) is provided in the mounting groove (5). The rear end of the mounting groove (5) is provided with an optical fiber head socket (7). The lens mounting cylinder (12) is provided on the other side of the vacuum flange (3). The lens mounting cylinder (12) is provided with a focusing lens (1).

2. The ultra-high vacuum fiber feedthrough with integrated beam focusing function according to claim 1, characterized in that, The fiber optic head mounting base (6) is also provided with a collimating lens group (4), which is located in front of the fiber optic head socket (7). A light-transmitting hole (9) is provided between the fiber optic head socket (7) and the collimating lens group (4).

3. The ultra-high vacuum fiber feedthrough with integrated beam focusing function according to claim 2, characterized in that, It also includes an optical fiber adjustment mechanism, which includes multiple sets of top wires. Each set of top wires includes two top wires (10) arranged in the same direction and opposite to each other. The optical fiber head mounting base (6) is also provided with multiple sets of adjustment holes. Each set of adjustment holes includes two adjustment holes along the same direction. The two adjustment holes of each set of adjustment holes are respectively distributed on both sides of the optical fiber head socket (7) and connected. The adjustment holes are perpendicular to the optical fiber socket. Multiple pairs of adjustment threaded holes are evenly distributed along the circumferential direction of the optical fiber head mounting base (6). The two top wires (10) of each set of top wires are respectively adapted and connected to the two adjustment holes of the corresponding set of adjustment holes. One end of the top wire (10) is inserted into the adjustment hole, and the other end of the top wire (10) is provided with an adjustment knob.

4. The ultra-high vacuum fiber feedthrough with integrated beam focusing function according to claim 3, characterized in that, The set screw (10) is provided with an external thread, and the adjustment hole is provided with an internal thread that matches the external thread of the set screw (10). The set screw (10) is screwed into the corresponding adjustment hole until it abuts against the fiber optic head.

5. The ultra-high vacuum fiber feedthrough with integrated beam focusing function according to claim 4, characterized in that, The bottom of the mounting groove (5) is provided with a window mounting hole that penetrates the vacuum flange (3), and a sealing window (2) is provided in the window mounting hole.

6. The ultra-high vacuum fiber feedthrough with integrated beam focusing function according to claim 1, characterized in that, The lens mounting tube (12) is also provided with an exhaust port (14).

7. The ultra-high vacuum fiber feedthrough with integrated beam focusing function according to claim 1, characterized in that, It also includes a position adjustment mechanism for the focusing lens (1), the position adjustment mechanism includes a first fixing ring (11) and a second fixing ring (13), the lens mounting cylinder (12) is provided with an internal thread, the first fixing ring (11) and the second fixing ring (13) are both provided with external threads that are adapted to the internal threads of the lens mounting cylinder (12), and the focusing lens (1) is disposed between the first fixing ring (11) and the second fixing ring (13).

8. The ultra-high vacuum fiber feedthrough with integrated beam focusing function according to claim 1, characterized in that, The fiber optic connector (7) is also provided with a fiber optic head fixing buckle (8).

9. The ultra-high vacuum fiber feedthrough with integrated beam focusing function according to claim 5, characterized in that, The fiber optic connector (7), light-transmitting hole (9), collimating lens group (4), sealing window (2), and focusing lens (1) share a common central axis.

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