Testing device for representing optical field information in optical fiber

Abstract

The utility model belongs to the technical field of optical detection, and discloses a testing device for representing optical field information in an optical fiber, which comprises a laser, a light beam emitted by the laser sequentially penetrates through a first lens and a second lens, then is emitted by a first reflector and sequentially enters a first polaroid and a first 1 / 2 wave plate, and then enters a second polaroid and a second 1 / 2 wave plate; the light beam enters a spatial light modulator and is emitted to become linear polarization vortex light, the polarization vortex light passes through a second 1 / 2 wave plate and a vortex wave plate and then is reflected by a second reflector, the reflected light beam enters an objective lens to be focused and then enters an optical fiber, and optical fiber end face near-field information received by an optical fiber scanning probe is sent to a beam splitter; the cutting knife is used for cutting the optical fiber with different lengths, near-field light fields and spinning distribution of the end faces of the cut optical fiber with different lengths are tested, the distribution conditions of light fields, tracks and spinning angular momentum of radial polarization vortex light at different positions in the optical fiber are analyzed, and the transmission condition of the light in the optical fiber is described more accurately.

Description

Technical Field

[0001] The utility model belongs to the technical field of optical detection, and in particular relates to a testing device for characterizing light field information inside an optical fiber. Background Art

[0002] Traditional communications include wireless communications and wired communications, and wired communications are currently mainly fiber-optic communications, that is, light is used as the signal carrier and optical fiber is the medium for light transmission. With the development of communication technology, wavelength division multiplexing, space division multiplexing, mode multiplexing and other technologies are used to increase the transmission capacity of optical fiber. In order to further improve the transmission capacity of optical fiber, different types of new structural beams and new optical fibers are used. In the study of optical fiber transmission, the study of the transmission of light beams inside the optical fiber is mainly carried out by analyzing the far-field light beam at the optical fiber output end, and then indirectly analyzing the distribution of the light beam transmitted inside the optical fiber. However, due to the influence of scattering and diffraction of the optical fiber end face, and the long-distance transmission of the light beam after output, there are certain errors and inaccuracies in analyzing the light beam transmitted inside the optical fiber by the far-field detection method at the output end. Utility Model Content

[0003] In order to solve the technical problems existing in the prior art, the utility model provides a testing device for characterizing the light field information inside an optical fiber, which further and more accurately describes the transmission of light inside the optical fiber by detecting the near-field information of the optical fiber end face.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a testing device for characterizing the light field information inside an optical fiber, comprising a laser, a first lens and a second lens are arranged at the laser output end, the first lens and the second lens are arranged in parallel, the light beam emitted by the laser output end is arranged toward the incident end of the first lens, and the output end of the first lens and the incident end of the second lens are arranged opposite to each other.

[0005] The emission end of the second lens is arranged toward the reflection surface of the first reflection mirror, and the reflection surface of the first reflection mirror is arranged tilted relative to the second lens.

[0006] The output end of the first reflector is arranged toward the incident end of the first polarizer, the output end of the first polarizer is arranged toward the incident end of the first 1 / 2 wave plate, and the output end of the first 1 / 2 wave plate is arranged toward the incident end of the spatial light modulator.

[0007] The output end of the spatial light modulator is arranged toward the incident end of the second 1 / 2 wave plate, and the output end of the second 1 / 2 wave plate is arranged toward the incident end of the vortex wave plate.

[0008] The output end of the vortex wave plate is arranged toward the reflection surface of the second reflection mirror, the reflection surface of the second reflection mirror is arranged tilted relative to the vortex wave plate, and the output end of the second reflection mirror is arranged toward the incident end of the objective lens.

[0009] The output end of the objective lens enters the optical fiber, and the receiving end of the optical fiber scanning probe is within the near field area from the optical fiber end face. The signal transmission end received by the optical fiber scanning probe is connected to the input end of the beam splitter through the optical fiber.

[0010] The first output end of the beam splitter is connected to the incident end of the first 1 / 4 wave plate through an optical fiber, the output end of the first 1 / 4 wave plate is arranged toward the incident end of the second polarizer, the output end of the second polarizer is arranged toward the incident end of the first photomultiplier tube, and the output end of the first photomultiplier tube is connected to the terminal processing device.

[0011] The second output end of the beam splitter is connected to the incident end of the second photomultiplier tube through an optical fiber, and the output end of the second photomultiplier tube is connected to the terminal processing device.

[0012] The third output end of the beam splitter is connected to the incident end of the second 1 / 4 wave plate through an optical fiber, the output end of the second 1 / 4 wave plate is arranged toward the incident end of the third polarizer, the output end of the third polarizer is arranged toward the incident end of the third photomultiplier tube, and the output end of the third photomultiplier tube is connected to the terminal processing device.

[0013] The optical axis of the first quarter wave plate is +45° relative to the optical axis of the second polarizer. 。 Arrangement.

[0014] The optical axis of the second quarter wave plate is -45 degrees relative to the optical axis of the third polarizer. 。 Arrangement.

[0015] Compared with the prior art, the specific beneficial effects of the utility model are embodied in that: the utility model can more accurately reflect the transmission of the light beam inside the optical fiber by detecting the near-field information of the optical fiber end face using a near-field scanning device, avoid the inaccurate information caused by light beam scattering, diffraction, propagation, etc. caused by the far-field detection method, and provide a new research idea and test device for the research of optical fiber medium transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the utility model.

[0017] In the figure, 1 is a laser, 2 is a first lens, 3 is a second lens, 4 is a first reflector, 5 is a first polarizer, 6 is a first 1 / 2 wave plate, 7 is a spatial light modulator, 8 is a second 1 / 2 wave plate, 9 is a vortex wave plate, 10 is a second reflector, 11 is an objective lens, 12 is a fiber scanning probe, 13 is a beam splitter, 14 is a first 1 / 4 wave plate, 15 is a second polarizer, 16 is a first photomultiplier tube, 17 is a second photomultiplier tube, 18 is a second 1 / 4 wave plate, 19 is a third polarizer, 20 is a third photomultiplier tube, and 21 is a terminal processing device. DETAILED DESCRIPTION

[0018] In order to make the technical problems, technical solutions and beneficial effects to be solved by 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.

[0019] A test device for characterizing the light field information inside an optical fiber. The device is used to analyze the transmission of radially polarized vortex light in the optical fiber, improve the near-field scanning microscope, achieve precise vertical fixation of the optical fiber medium and three-dimensional movement of the optical fiber medium, and build a near-field light field and spin angular momentum scanning imaging system for the optical fiber end face.

[0020] like Figure 1 As shown, the device includes a laser 1. The Gaussian beam emitted by the laser 1 is expanded by the first lens 2 and the second lens 3. The expanded Gaussian beam is emitted by the first reflector 4 and enters the first polarizer 5. The Gaussian beam after passing through the first polarizer 5 becomes a linearly polarized Gaussian beam. The linearly polarized Gaussian beam passes through the first 1 / 2 wave plate 6 and enters the spatial light modulator 7. The first 1 / 2 wave plate 6 is used to adjust the polarization of the incident beam to make it consistent with the spatial light modulator 7. After being emitted from the spatial light modulator 7, the light becomes a linearly polarized vortex light. The linearly polarized vortex light passes through the second 1 / 2 wave plate 8 and the vortex wave plate 9 and becomes a radially polarized vortex light. The radially polarized vortex light is focused by the objective lens 11 and enters the optical fiber.

[0021] The optical fiber scanning probe 12 is placed on the end face of the optical fiber output end, and the different parameter distributions of the near-field light field of the radially polarized vortex light on the end face of the optical fiber output end are tested respectively. The near-field information of the optical fiber end face received by the optical fiber scanning probe 12 enters the beam splitter 13 through the optical fiber. The near-field information output by the first output end of the beam splitter 13 passes through the first 1 / 4 wave plate 14, the second polarizer 15, and the first photomultiplier tube 16 in sequence and then enters the terminal processing device 21 for analysis.

[0022] The near-field information outputted from the second output end of the beam splitter 13 enters the terminal processing device 21 through the second photomultiplier tube 17 for analysis.

[0023] The near-field information outputted from the third output end of the beam splitter 13 passes through the second 1 / 4 wave plate 18, the third polarizing plate 19, and the second photomultiplier tube 17 in sequence and then enters the terminal processing device 21 for analysis.

[0024] The first photomultiplier tube 16, the second photomultiplier tube 17 and the third photomultiplier tube 20 amplify the signal, and the terminal processing device 21 analyzes the information, and then analyzes the transmission of the radially polarized vortex light in the optical fiber. The optical fiber is cut to different lengths using a cutting knife, and the different parameter distributions of the near-field light field of the optical fiber end face of different lengths after cutting are tested to analyze the light field parameter distribution of the radially polarized vortex light at different positions inside the optical fiber.

[0025] exist Figure 1 In the figure, the grey line is the transmission path of light, and the terminal processing device 21 in this embodiment is a computer.

[0026] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the scope of the present invention.

Claims

1. A test device for characterizing the optical field information inside an optical fiber, characterized in that: The laser (1) comprises a first lens (2) and a second lens (3) arranged at the output end of the laser (1), the first lens (2) and the second lens (3) being arranged in parallel, the light beam emitted from the output end of the laser (1) being arranged toward the incident end of the first lens (2), and the output end of the first lens (2) and the incident end of the second lens (3) being arranged opposite to each other; The emission end of the second lens (3) is arranged toward the reflection surface of the first reflection mirror (4), and the reflection surface of the first reflection mirror (4) is arranged tilted relative to the second lens (3); The output end of the first reflector (4) is arranged toward the incident end of the first polarizer (5), the output end of the first polarizer (5) is arranged toward the incident end of the first 1 / 2 wave plate (6), and the output end of the first 1 / 2 wave plate (6) is arranged toward the incident end of the spatial light modulator (7); The output end of the spatial light modulator (7) is arranged toward the incident end of the second 1 / 2 wave plate (8), and the output end of the second 1 / 2 wave plate (8) is arranged toward the incident end of the vortex wave plate (9); The output end of the vortex wave plate (9) is arranged toward the reflection surface of the second reflection mirror (10), the reflection surface of the second reflection mirror (10) is arranged tilted relative to the vortex wave plate (9), and the output end of the second reflection mirror (10) is arranged toward the incident end of the objective lens (11); The output end of the objective lens (11) enters the optical fiber, the optical fiber is connected to the receiving end of the optical fiber scanning probe (12), and the signal transmission end of the optical fiber scanning probe (12) is connected to the input end of the beam splitter (13) through the optical fiber; The first output end of the beam splitter (13) is connected to the incident end of the first quarter wave plate (14) through an optical fiber, the output end of the first quarter wave plate (14) is arranged toward the incident end of the second polarizer (15), the output end of the second polarizer (15) is arranged toward the incident end of the first photomultiplier tube (16), and the output end of the first photomultiplier tube (16) is connected to the terminal processing device (21); The second output end of the beam splitter (13) is connected to the incident end of the second photomultiplier tube (17) through an optical fiber, and the output end of the second photomultiplier tube (17) is connected to the terminal processing device (21); The third output end of the beam splitter (13) is connected to the incident end of the second quarter wave plate (18) through an optical fiber, the output end of the second quarter wave plate (18) is arranged toward the incident end of the third polarizer (19), the output end of the third polarizer (19) is arranged toward the incident end of the third photomultiplier tube (20), and the output end of the third photomultiplier tube (20) is connected to the terminal processing device (21).

2. A test device for characterizing the optical field information inside an optical fiber according to claim 1, characterized in that: The optical axis of the first quarter wave plate (14) is arranged at 45 degrees relative to the optical axis of the second polarizing plate (15).

3. The test device for characterizing the optical field information inside an optical fiber according to claim 1, characterized in that: The optical axis of the second quarter wave plate (18) is arranged at -45 degrees relative to the optical axis of the third polarizer (19).

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