Device for measuring linear optical effect through light transmittance

Abstract

The utility model relates to the technical field of material property measurement, and discloses a device for measuring linear optical effect through light transmissivity, which comprises an optical platform, a laser is mounted on the optical platform, an attenuator is arranged on the right side of the laser, a beam splitter is arranged on the right side of the attenuator, a polarizer is arranged on the right side of the beam splitter, and the polarizer is arranged on the right side of the beam splitter. A quarter-wavelength wave plate is arranged on the right side of the polarizer, a diaphragm is arranged on the right side of the quarter-wavelength wave plate, a film sample is arranged on the right side of the diaphragm, and a first optical detector is fixedly installed on the right side of the optical platform. According to the utility model, the polarization analyzer driven by the rotating table is combined with the optical detector I, so that the light transmission intensities at different angles can be measured. In combination with the reference light intensity measured by the second light detector, the light transmissivity at different angles can be obtained, so that the dichroism and birefringence effect information of the sample can be obtained.

Description

Technical Field

[0001] The utility model relates to the technical field of material property measurement, in particular to a device for measuring linear optical effects through light transmittance. Background Art

[0002] Soft matter, such as magnetic colloids and liquid crystals, is a material that lies between solids and ideal fluids. The optical effect of a material refers to its response to light fields. Measuring the optical effects of anisotropic media not only reveals important macroscopic properties but also serves as a crucial tool for uncovering its structure.

[0003] Linear optical effects are those that are independent of the intensity of the incident light, primarily dichroism and birefringence. When light propagates in an anisotropic medium along a certain direction, if it is the same as in an isotropic medium, this direction is called the optical axis. The optical axis of liquid crystals is the director of the liquid crystal molecules, and the optical axis of magnetic colloids is the direction of the applied magnetic field. Dichroism is observed when the absorption perpendicular to and parallel to the optical axis differs; birefringence is observed when the refractive index perpendicular to and parallel to the optical axis differs. Therefore, a measurement device is required to perform these measurements.

[0004] Existing measurement techniques measure dichroism and birefringence separately, which is not only time-consuming but also fails to ensure consistency in sample state and detection area when measuring both effects. Furthermore, existing optical measurement devices for the visible light range often use silicon photodetectors for optical signal acquisition. However, the current signal generated by silicon photodiodes varies nonlinearly with the incident light intensity, easily distorting the acquired information and significantly limiting the measured light intensity range. While optical power meters can address this issue, they cannot meet the requirements for high-speed dynamic measurements. Therefore, a device for measuring linear optical effects using light transmittance is proposed to address these issues. Utility Model Content

[0005] In order to achieve the above-mentioned purpose, the utility model adopts the following technical solution: a device for measuring linear optical effects by light transmittance, comprising an optical platform, a laser is installed on the optical platform, an attenuator is provided on the right side of the laser, a beam splitter is provided on the right side of the attenuator, a polarizer is provided on the right side of the beam splitter, a quarter-wave plate is provided on the right side of the polarizer, an aperture is provided on the right side of the quarter-wave plate, a thin film sample is provided on the right side of the aperture, a light detector 1 is fixedly installed on the right side of the top wall of the optical platform, a rotating platform with a built-in polarizer is provided on the left side of the light detector 1, and the optical platform is provided with a computing component.

[0006] As a further description of the above technical solution:

[0007] The computing component includes a data acquisition card, and the optical platform is equipped with a computer.

[0008] As a further description of the above technical solution:

[0009] The rotating platform with built-in polarizer can realize 360° rotation and adjustment of the polarization direction of the polarizer through a data acquisition card and a computer via LabVIEW software. A light detector 1 is provided on the right side of the rotating platform with built-in polarizer.

[0010] As a further description of the above technical solution:

[0011] Both the first and second photodetectors are silicon photodiodes that are sensitive to photoelectric signals and can realize high-dynamic signal materials. Through the use of a data acquisition card and a computer, and through numerical calculations using LabVIEW software, the nonlinear response problem of the photodetectors can be eliminated. In addition, the rotating stage with a built-in polarizer can realize the collection and processing of transmitted light intensity signals under different polarization directions.

[0012] As a further description of the above technical solution:

[0013] The left and right sides of the bottom wall of the optical platform are fixedly connected with support frames, and the two support frames are symmetrically designed. Corner pads are fixedly installed on the front and back sides of the bottom of the two support frames.

[0014] As a further description of the above technical solution:

[0015] Based on the compatibility of this device with magnetic control and electric control devices, it can realize the measurement of linear optical effects such as magneto-optical effect, electro-optical effect and magnetic and electric coupling-optical effect of materials.

[0016] The utility model has the following beneficial effects:

[0017] 1. In this utility model, the polarization analyzer driven by the rotating stage, in conjunction with photodetector 1, can measure the light transmission intensity at different polarization angles. Combined with the reference light intensity measured by photodetector 2, the light transmittance at different polarization angles can be obtained, thereby providing information on the dichroism and birefringence effects of the sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a three-dimensional diagram of a device for measuring linear optical effects by light transmittance proposed in the present invention;

[0019] Figure 2 This is a schematic structural diagram of the optical system of an apparatus for measuring linear optical effects by light transmittance proposed by the present invention.

[0020] Legend:

[0021] 1. Laser; 2. Attenuator; 3. Beam splitter; 4. Polarizer; 5. Quarter-wave plate; 6. Aperture diaphragm; 7. Thin film sample; 8. Rotating table with built-in polarizer; 9. Photodetector 1; 10. Photodetector 2; 11. Data acquisition card; 12. Calculator; 13. Support frame; 14. Corner pads; 15. Optical platform. DETAILED DESCRIPTION

[0022] 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 embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0023] Reference Figure 1 and Figure 2 The utility model provides an embodiment: a device for measuring linear optical effects by light transmittance, comprising an optical platform 15, wherein the optical platform 15 is mounted with a laser 1, an attenuator 2 is disposed on the right side of the laser 1, a beam splitter 3 is disposed on the right side of the attenuator 2, a polarizer 4 is disposed on the right side of the beam splitter 3, a quarter-wave plate 5 is disposed on the right side of the polarizer 4, an aperture 6 is disposed on the right side of the quarter-wave plate 5, a thin film sample 7 is disposed on the right side of the aperture 6, a light detector 9 is mounted on the right side of the top wall of the optical platform 15, a rotating stage 8 with a built-in analyzer is disposed on the left side of the light detector 9, and a computing component is mounted on the optical platform 15;

[0024] Specifically, the rotating stage 8 with the built-in polarizer is driven by the computer LabVIEW program to rotate 360°, and combined with the light detector 9, the light transmission intensity at different polarization angles can be measured. Combined with the reference light intensity measured by the light detector 10, the light transmittance at different polarization angles can be obtained, thereby obtaining information on the dichroism and birefringence effect of the sample.

[0025] Reference Figure 1 , the computing components include a data acquisition card 11 and a computer 12; the light detector 1 9 and the light detector 2 10 are both silicon photodiodes that are sensitive to photoelectric signals and can realize high dynamic signal materials. Through the data acquisition card 11 and the computer 12, the nonlinear response problem of the light detector can be eliminated by numerical calculation processing using LabVIEW software. In addition, the rotating table 8 with a built-in polarizer can realize the acquisition and processing of transmitted light intensity signals under different polarization directions; the left and right sides of the bottom wall of the optical platform 15 are fixedly connected with support frames 13, and the two support frames 13 are symmetrically designed. The front and rear sides of the bottom of the two support frames 13 are fixedly installed with corner pads 14;

[0026] Specifically, the computer LabVIEW software program in the computing component drives the data acquisition card to collect the electrical signals measured by the light detector, and then the LabVIEW program performs numerical calculations and corrections on the data to obtain a light transmittance signal. The support frame 13 and the corner pad 14 can improve the stability of the device during operation.

[0027] Reference Figure 1 and Figure 2 , based on the compatibility of the device with magnetic control and electric control devices, it can realize the measurement of linear optical effects such as magneto-optical effect, electro-optical effect and magnetic and electric coupling-optical effect of materials;

[0028] Working principle: The laser emitted by laser 1 passes through variable attenuator 2 to obtain a beam of a certain power, and then the beam is split into two beams by beam splitter: one beam with intensity I0 is used as reference light; the other beam with intensity is used as detection light. The detection light passes through polarizer 4 and quarter-wave plate 5 to produce circularly polarized light. The angle between the polarization direction of the polarizer and the main axis of the quarter-wave plate is 45° to produce right-handed circularly polarized light or -45° to produce left-handed circularly polarized light. The circularly polarized light is adjusted to its intensity I0 by variable aperture 6. This aperture can also reduce the stray light irradiated on the sample 7. By driving the analyzer and the photodetector 1 9 and the photodetector 2 10 by the rotating stage 8, the angular distribution of the light transmittance can be obtained, thereby determining the linear optical effect of the sample. After the circularly polarized light passes through the sample 7 with optical anisotropy, the transmitted light will be converted into elliptically polarized light. The rotating stage 8 is set to drive the analyzer to rotate so that the analyzer orientation is along the x-axis as the starting angle, that is, θ = 0. The transmitted light intensity I with different polarization rotation angles θ can be obtained by the rotatable analyzer and the detector 1 9. t (θ), which is I t (θ)-θ curve, the analog electrical signal measured by the detector 1 9 can be converted into a digital electrical signal by the data acquisition card 11. In addition, another light signal with an intensity of I0 obtained by the beam splitter 3 can be converted into an analog electrical signal by the light detector 2 10, and then converted into a digital electrical signal by the data acquisition card 11. The digital signals from the light detector 1 9 and the light detector 2 10 collected by the data acquisition card 11 are stored in the computer device 12 for processing, and finally the transmittance angular distribution curve is obtained, T(=I t The (θ) / I0)-θ curve is the ratio of the sum obtained by the measurement light path and the reference light path passing through the photodetector 1 9 and the photodetector 2 10 respectively, which can eliminate the influence of the laser emission fluctuation.

[0029] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent replacements for some of the technical features therein. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A device for measuring linear optical effects by light transmittance, comprising an optical platform (15), characterized in that: The optical platform (15) is equipped with a laser (1), an attenuator (2) is provided on the right side of the laser (1), a beam splitter (3) is provided on the right side of the attenuator (2), a polarizer (4) is provided on the right side of the beam splitter (3), a quarter-wave plate (5) is provided on the right side of the polarizer (4), an aperture (6) is provided on the right side of the quarter-wave plate (5), a thin film sample (7) is provided on the right side of the aperture (6), a light detector (9) is fixedly installed on the right side of the top wall of the optical platform (15), a rotating platform (8) with a built-in polarizer is provided on the left side of the light detector (9), and the optical platform (15) is provided with a computing component.

2. The device for measuring linear optical effects by light transmittance according to claim 1, characterized in that: The computing component includes a data acquisition card (11), and the optical platform (15) is equipped with a computer (12).

3. The device for measuring linear optical effects by light transmittance according to claim 1, wherein: The rotating platform (8) with a built-in polarizer can realize 360-degree rotation and adjustment of the polarization direction of the polarizer through a data acquisition card (11) and a computer (12) via LabVIEW software. A light detector (9) is provided on the right side of the rotating platform (8) with a built-in polarizer.

4. The device for measuring linear optical effects by light transmittance according to claim 1, wherein: The light detector 1 (9) and the light detector 2 (10) are both silicon photodiodes that are sensitive to photoelectric signals and can realize high dynamic signal materials. Through the data acquisition card (11) and the computer (12), the nonlinear response problem of the light detector can be eliminated by numerical calculation processing of LabVIEW software. In addition, the rotating stage (8) with a built-in polarizer can realize the collection and processing of transmitted light intensity signals under different polarization directions.

5. The device for measuring linear optical effects by light transmittance according to claim 4, characterized in that: The left and right sides of the bottom wall of the optical platform (15) are both fixedly connected with support frames (13), the two support frames (13) are both symmetrically designed, and the front and rear sides of the bottoms of the two support frames (13) are both fixedly installed with corner pads (14).

6. The device for measuring linear optical effects by light transmittance according to claim 1, wherein: Based on the compatibility of this device with magnetic control and electric control devices, it can realize the measurement of the material's magneto-optical effect, electro-optical effect and magnetic and electric coupling-optical effect linear optical effect.

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