Interferometric integrated temperature and vibration optical fiber sensing demonstration device

Abstract

The invention discloses an interference type integrated temperature and vibration optical fiber sensing demonstration device, relates to the field of optical fiber sensing demonstration teaching aids, and aims to solve the problem that both the prior art and the optical fiber sensing demonstration teaching aids cannot be considered. The vibration platform drives the plate spring steel to reciprocate to form vibration through a stepping motor controlled by a frequency controller; and tail fibers of the experiment arm and the reference arm are fixed on a movable pipe of the optical fiber fixing mechanism and are provided with bolts for locking. The optical fiber sensing process is quantitatively visualized based on Young's double-slit interference and the MZI principle, the principle can be deeply understood in the experiment process, the experiment precision is guaranteed while operability is achieved, and temperature and position changes can be rapidly calculated through stripe movement while experiment observation is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of optical fiber sensing demonstration teaching aids, in particular to an interference type integrated temperature and vibration optical fiber sensing demonstration device. Background Art

[0002] The WGX-11 fiber optic sensor experiment instrument is currently used in modern university physics experiments. Although this device allows students to clearly see the changes in the movement of interference fringes caused by changes in temperature and stress, it cannot perform quantitative calculations and has great limitations. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the existing defects and provide an interference type integrated temperature and vibration optical fiber sensing demonstration device, which can effectively solve the problems in the background technology.

[0004] In order to achieve the above-mentioned purpose, the present invention discloses an interference type integrated temperature and vibration optical fiber sensing demonstration device, which adopts the technical scheme of comprising an optical fiber double-beam interference experimental device, the optical fiber double-beam interference experimental device comprising an experimental arm and a reference arm, a heating platform is provided below the experimental arm, and the influence of temperature on optical fiber interference fringes can be explored by starting the heating platform, an optical fiber ring is provided on the experimental arm, and a vibration platform is provided below the optical fiber ring, and the influence of vibration on optical fiber interference fringes can be explored; the vibration platform comprises a frame, a stepper motor is provided on the frame, the output end of the stepper motor is connected to a transmission mechanism, the transmission mechanism is connected to a leaf spring steel, the leaf spring steel is connected to the frame, the optical fiber ring is connected to the leaf spring steel, the stepper motor is electrically connected to a frequency controller, and the vibration frequency of the vibration platform can be effectively controlled by controlling the frequency controller; the pigtails of the experimental arm and the reference arm are connected to an optical fiber fixing mechanism, the optical fiber fixing mechanism is equipped with a lens of the optical fiber double-beam interference experimental device, the pigtails of the experimental arm and the reference arm are located at the focus of the lens, and the optical fiber fixing mechanism can be more convenient for fixing the pigtails and for focusing the experimental arm and the reference arm at the focus of the lens.

[0005] As a preferred technical solution of the present invention, the transmission mechanism includes a connecting member, one end of the connecting member is fixedly connected to the output shaft of the stepper motor, and the other end is hinged with a connecting rod, and the connecting rod is also hinged with an articulated seat, and the articulated seat is fixedly connected to the leaf spring steel. The output end of the stepper motor drives the connecting member to rotate, and the connecting member drives the articulated seat to move up and down through the connecting rod transmission, thereby driving the leaf spring steel to vibrate.

[0006] As a preferred technical solution of the present invention, the optical fiber fixing mechanism includes a base, the base is connected to a support rod, the support rod is provided with a through hole, a movable tube is slidably connected in the through hole, and the support rod is also provided with a threaded hole communicating with the through hole, a bolt is engaged in the threaded hole, and the end face of the bolt is in sliding contact with the movable tube; the pigtails of the experimental arm and the reference arm are fixed in the movable tube, and by sliding the movable tube in the through hole, the spacing between the pigtails of the experimental arm and the reference arm and the lens can be adjusted, thereby adjusting the imaging effect, and after adjusting to the appropriate position, the position of the movable tube can be fixed by bolts.

[0007] As a preferred technical solution of the present invention, a mounting seat is provided on the support rod, the lens is mounted on the mounting seat, and the lens and the through hole are coaxial, so as to facilitate focusing of the pigtail.

[0008] As a preferred technical solution of the present invention, the movable tube is a columnar structure, and a slit is provided on the movable tube, and the pigtails of the experimental arm and the reference arm are in sliding contact in the slit; a plug is installed in the slit, and the plug is in sliding contact with the pigtails of the experimental arm and the reference arm. After the pigtail is installed in the slit, the pigtail in the slit can be fixed by installing the plug.

[0009] As a preferred technical solution of the present invention, the optical fiber used in the optical fiber dual-beam interference experimental device is a bare optical fiber. Compared with an optical fiber with an outer sheath, a bare optical fiber is more sensitive to temperature and vibration.

[0010] As a preferred technical solution of the present invention, the optical fiber used in the optical fiber dual-beam interference experimental device is a 650nm optical fiber, and the diameter of the optical fiber ring is 2.32cm. This diameter can ensure vibration sensitivity while minimizing the attenuation of optical signals during the vibration process, thereby ensuring the accuracy of vibration measurement.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention quantitatively visualizes the process of optical fiber sensing based on Young's double-slit interference and MZI principles, which is conducive to an in-depth understanding of the principles during experiments, and ensures the accuracy of the experiments while achieving operability; uses bare optical fibers for light transmission, and sets the bare optical fibers on a heating platform and a vibration platform, which can accurately and sensitively feedback the effects of temperature and vibration on the interference fringes of the optical fibers, thereby facilitating experimental observations and quickly calculating temperature and position changes through fringing movement; the vibration platform uses a stepper motor and a transmission mechanism to drive the leaf spring steel to vibrate, thereby forming a vibration factor under the optical fiber ring of the optical fiber, which can make the vibration factor of the demonstration device more controllable; uses an optical fiber fixing mechanism to fix the pigtails of the experimental arm and the reference arm, which not only makes the fixation of the pigtails simpler and more stable, but also makes it easier to adjust the spacing between the pigtails and the lens, and can ensure that the light waves emitted by the pigtails can produce clear interference fringes. Taking into account the axial heat conduction of the optical fiber, after temperature correction, the sensitivity of the present invention to temperature and vibration reaches 32.078 nm / °C and 0.001 Hz respectively, that is, under experimental conditions, it has high sensitivity and accuracy and can meet the requirements of precision measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 The schematic diagram of the vibration platform structure of the present invention is Figure 1 ; Figure 3 The schematic diagram of the vibration platform structure of the present invention is Figure 2 ; Figure 4 The schematic diagram of the transmission mechanism structure of the present invention is Figure 1 ; Figure 5 The schematic diagram of the transmission mechanism structure of the present invention is Figure 2 ; Figure 6 FIG. 1 is a schematic diagram of the structure of the optical fiber fixing mechanism of the present invention. Figure 1 ; Figure 7 FIG. 1 is a schematic diagram of the structure of the optical fiber fixing mechanism of the present invention. Figure 2 ; Figure 8 It is a schematic diagram of the movable tube structure of the present invention; Fig. 9 It is a schematic diagram of the side view structure of the movable tube of the present invention; Fig.10 It is a schematic diagram of the AA cross-sectional structure of the present invention; Fig.11 This is a graph showing the temperature variation over time obtained in Example 1 of the present invention; Fig.12This is a graph showing the variation of the vibration position over time obtained in Example 1 of the present invention.

[0013] In the figure: 1. light source; 2. one-to-two fiber coupler; 3. experimental arm; 301. fiber ring; 4. reference arm; 5. fiber fixing mechanism; 501. base; 502. support rod; 503. mounting seat; 504. lens; 505. movable tube; 5051. slit; 506. bolt; 507. plug; 6. CCD; 7. computer; 8. heating table; 9. vibration platform; 901. frame; 902. stepping motor; 903. transmission mechanism; 931. connector; 932. connecting rod; 933. hinge seat; 904. leaf spring steel. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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. Example 1

[0015] like Figures 1 to 10 As shown, the present invention discloses an interference type integrated temperature and vibration optical fiber sensor demonstration device, the technical scheme adopted is, including an optical fiber double-beam interference experimental device, which includes a light source 1, the light source 1 adopts a 650nm band laser pen, the laser emission end of which is connected to the input end of a one-to-two optical fiber coupler 2 through an optical fiber, and the two output ends of the one-to-two optical fiber coupler 2 are respectively connected to an optical fiber, namely an experimental arm 3 and a reference arm 4, an optical fiber ring 301 is wound around the experimental arm 3, and the optical fiber ring 301 is bundled with a thin wire to maintain its bending shape. In order to obtain an interference fringe image, the pigtails of the experimental arm 3 and the reference arm 4 are fixed on the optical fiber fixing mechanism 5, as shown in FIG. Figure 6 , Figure 7 As shown, the optical fiber fixing mechanism 5 includes a base 501, a support rod 502 is arranged on the base 501, an L-shaped mounting seat 503 is arranged on the support rod 502, a circular mounting hole is provided on the mounting seat 503, and a lens 504 is installed in the mounting hole. In order to position the pigtail, a through hole is provided on the support rod 502, the through hole is coaxial with the mounting hole, and a movable tube 505 is slidably connected in the through hole, as shown in FIG. Figure 8 , Fig. 9 , Fig.10As shown, the movable tube 505 is a columnar structure, and a slit 5051 is provided on its curved surface. The two ends of the slit 5051 are connected to the outside world at the end surface of the movable tube 505. The pigtail is inserted into the slit 5051. In order to fix the pigtail, a plug 507 is provided in the slit 5051. The plug 507 fixes the pigtail in the slit 5051 by friction. In order to obtain a clearer interference fringe image, the movable tube 505 needs to be moved in the perforation to adjust the distance between the pigtail and the lens 504, so that the light wave exit point of the pigtail is located at the focus of the lens 504 as much as possible. After the position of the movable tube 505 is adjusted, in order to position the movable tube 505, a threaded hole that penetrates the perforation is provided on the end surface of the support rod 502, and a bolt 506 is engaged in the threaded hole. The end surface of the bolt 506 is in sliding contact with the movable tube 505. A CCD 6 is provided at the rear end of the lens 504, and the rear end of the CCD 6 is connected to a computer 7 via an optical fiber.

[0016] In order to demonstrate the influence of temperature and vibration on the interference fringes of optical fiber, the optical fiber of the experimental arm 3 is attached to the heating platform of the heating platform 8 by using adhesive tape, and the optical fiber ring 301 is fixed on the vibration platform 9, as shown in FIG. Figure 2 , Figure 3 As shown, the vibration platform 9 includes a frame 901, a stepper motor 902 is arranged on the frame 901, and the output end of the stepper motor 902 is connected to a transmission mechanism 903, as shown in FIG. Figure 4 , Figure 5 As shown, the transmission mechanism 903 includes a connecting member 931, one end of the connecting member 931 is fixedly connected to the output shaft of the stepper motor 902, and the other end is hinged to one end of the connecting rod 932, and the other end of the connecting rod 932 is hinged to the hinge seat 933, and the hinge seat 933 is L-shaped, and its vertical section is hinged to the connecting rod 932, and the horizontal section is fixedly connected to one end of the leaf spring steel 904, and the other end of the leaf spring steel 904 is fixedly connected to the frame 901, and the stepper motor 902 is electrically connected to the frequency controller. Use tape to fix the optical fiber ring 301 on the leaf spring steel 904.

[0017] The optical fibers used in this embodiment are all single-mode optical fibers with a core diameter of 8.2 μm, a cladding diameter of 125 μm, and a transmission wavelength of 650 nm. Considering that the optical fiber with an outer sheath is insensitive to temperature and vibration, in order to improve the sensitivity of the sensor, bare optical fiber is selected. In order to ensure vibration sensitivity while minimizing the attenuation of optical signals during vibration, the diameter of the optical fiber ring 301 is maintained at 2.32 cm.

[0018] Working principle of the present invention: Build an optical fiber double-beam interference experimental device, install the pigtails of the experimental arm 3 and the reference arm 4 into the slit 5051 opened by the movable tube 505 of the optical fiber fixing mechanism 5, and fix them with a plug 507, turn on the light source 1, emit 650 nm laser, and transmit the laser to the one-to-two optical fiber coupler 2 through the optical fiber for splitting processing, and the laser enters the experimental arm 3 and the reference arm 4, adjust the distance between the movable tube 505 and the lens 504 until a clear interference fringe image appears on the screen of the computer 7, and tighten the bolt 506 to fix the movable tube 505; use a thermocouple to detect the platform temperature of the heating platform 8, ensure that it is at room temperature, start the screen recording of the computer 7, turn on the switch of the heating platform 8, and set the heating temperature to 80 ℃, operate the frequency controller to start the stepper motor 902, set the vibration frequency to 1 Hz, and the stepper motor 902 drives the connecting piece 931 of the transmission mechanism 903 to rotate, and the connecting piece 931 is transmitted through the connecting rod 932, pulling the leaf spring steel 904 to drive the optical fiber ring 301 to vibrate up and down.

[0019] After the temperature of the heating platform 8 reaches the set temperature, the screen recording of the computer 7 is terminated, the heating platform 8 and the frequency controller are turned off, and the recorded video is imported into the Tracker software for image processing to obtain the collected data.

[0020] Import the collected data into Origin software and use the existing data analysis methods to obtain the following Fig.11 The temperature variation with time shown in the figure and Fig.12 As shown in the graph of vibration position changing with time, it can be observed that the vibration pattern is floating in an oscillating form and the temperature pattern is rising in a straight line trend.

[0021] The circuits and mechanical connections involved in the present invention are conventional means used by those skilled in the art, and technical inspiration can be obtained through a limited number of experiments, which are common knowledge.

[0022] The heating platform 8 and frequency controller used in this article are products available on the market, and other components not described in detail are all prior art.

[0023] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An interferometric integrated temperature and vibration optical fiber sensor demonstration device, comprising an optical fiber double-beam interference experimental device, wherein the optical fiber double-beam interference experimental device comprises an experimental arm (3) and a reference arm (4), and is characterized in that: A heating platform (8) is provided below the experimental arm (3), an optical fiber ring (301) is provided on the experimental arm (3), and a vibration platform (9) is provided below the optical fiber ring (301); the vibration platform (9) comprises a frame (901), a stepping motor (902) is provided on the frame (901), an output end of the stepping motor (902) is connected to a transmission mechanism (903), the transmission mechanism (903) is connected to a leaf spring steel (904), the leaf spring steel (904) is connected to the frame (901), the optical fiber ring (301) is connected to the leaf spring steel (904), and the stepping motor (902) is electrically connected to a frequency controller; the pigtails of the experimental arm (3) and the reference arm (4) are connected to an optical fiber fixing mechanism (5), a lens (504) of the optical fiber double-beam interference experimental device is installed on the optical fiber fixing mechanism (5), and the pigtails of the experimental arm (3) and the reference arm (4) are located at the focus of the lens (504).

2. The interferometric integrated temperature and vibration optical fiber sensing demonstration device according to claim 1, characterized in that: The transmission mechanism (903) comprises a connecting member (931), one end of the connecting member (931) is fixedly connected to the output shaft of the stepping motor (902), and the other end is hinged with a connecting rod (932), the connecting rod (932) is also hinged with an articulated seat (933), and the articulated seat (933) is fixedly connected to the leaf spring steel (904).

3. The interferometric integrated temperature and vibration optical fiber sensing demonstration device according to claim 1, characterized in that: The optical fiber fixing mechanism (5) comprises a base (501), the base (501) is connected to a support rod (502), the support rod (502) is provided with a through hole, a movable tube (505) is slidably connected in the through hole, the support rod (502) is also provided with a threaded hole communicating with the through hole, a bolt (506) is meshed in the threaded hole, and an end face of the bolt (506) is in sliding contact with the movable tube (505); the pigtails of the experimental arm (3) and the reference arm (4) are fixed in the movable tube (505).

4. The interferometric integrated temperature and vibration optical fiber sensing demonstration device according to claim 3 is characterized in that: The support rod (502) has a mounting seat (503), the mounting seat (503) has the lens (504) mounted on it, and the lens (504) and the through hole are coaxial.

5. The interferometric integrated temperature and vibration optical fiber sensing demonstration device according to claim 3 or 4, characterized in that: The movable tube (505) is a columnar structure, and a slit (5051) is provided on the movable tube (505), and the pigtails of the experimental arm (3) and the reference arm (4) are in sliding contact in the slit (5051); a plugging piece (507) is installed in the slit (5051), and the plugging piece (507) is in sliding contact with the pigtails of the experimental arm (3) and the pigtails of the reference arm (4).

6. The interferometric integrated temperature and vibration optical fiber sensing demonstration device according to claim 1, characterized in that: The optical fiber used in the optical fiber double-beam interference experimental device is a bare optical fiber.

7. The interferometric integrated temperature and vibration optical fiber sensing demonstration device according to claim 1 or 6, characterized in that: The optical fiber used in the optical fiber double-beam interference experimental device is a 650nm optical fiber, and the diameter of the optical fiber ring (301) is 2.32 cm.

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