Interferometer based on light speed adjustment

Abstract

The present application relates to the field of optical technology, particularly to interferometer. The interferometer based on light speed adjustment includes an interferometer system, the interferometer system includes a laser and optical device irradiated by the laser, and includes a light speed path difference fine adjustment system; the light speed path difference fine adjustment system includes a glass tube, a transparent liquid container and a two-way pump; the glass tube has a liquid supply port on the side wall, the liquid supply port is connected to one pump port of the two-way pump, the other pump port of the two-way pump is connected to the transparent liquid container, and the transparent liquid container stores transparent liquid; there is a vertical light path between the laser and at least one optical device, and the glass tube is vertically arranged in the vertical light path.

Description

Technical Field

[0001] This invention relates to the field of optical technology, and in particular to interferometers. Background Technology

[0002] An interferometer is a precision measuring instrument designed based on the principle of wave superposition. It is mainly used to obtain phase or optical path difference information of waves through interference phenomena, thereby indirectly measuring physical quantities. Its core principle is to split a wave (such as a light wave) into two or more beams, propagate them through different paths, and then superimpose them. The target parameters are derived by analyzing the changes in the interference fringes.

[0003] Interferometers can be classified according to different standards: Classified by structure: Single-path interferometers: such as the Sagnac interferometer, where interference waves propagate along the same path.

[0004] Multipath interferometers: such as the Michelson interferometer, in which light is split into two beams, reflected by different paths, and then superimposed.

[0005] According to the method of spectral dispersion: Wavefront decomposition: using sub-wave sources at different positions on the wavefront to form interference, such as Young's double-slit interference.

[0006] Amplitude decomposition: The amplitude is split into multiple beams by a beam splitter, such as in a Fabry-Perot interferometer.

[0007] Classified by testing technology Zero-difference detection: Using a reference signal of the same frequency to eliminate the influence of noise, such as a Mach-Zehnder interferometer.

[0008] Heterodyne detection: Utilizes two beams of light with similar frequencies to generate beat frequency signals, improving measurement accuracy; commonly used in laser interferometry. Main application areas: High-precision length and displacement measurement: Optical path difference is calculated by the number of shifts in interference fringes, achieving nanometer-level precision. For example, the Michelson interferometer was once used to define the international meter using the wavelength of the cadmium red spectral line.

[0009] Optical component inspection: Inspecting mirror flatness, lens aberrations, etc. Shearing interferometers generate interference patterns by staggering wavefronts, simplifying reference surface requirements.

[0010] Astronomical observations: Interferometric arrays composed of multiple telescopes (such as radio interferometers) can simulate ultra-large apertures and improve resolution. For example, the Michelson interferometer measures the angular diameter of stars, and heterodyne interferometry combined with lasers improves the accuracy of infrared astronomical observations.

[0011] Refractive index and medium analysis: The Fizeau interferometer measures gas density, liquid refractive index, etc., by measuring changes in optical path difference. It is commonly used to inspect optical planes.

[0012] Quantum Physics and Microscopic Research: Used for quantum entanglement experiments, surface stress analysis, and biomolecular interaction studies, such as Linnicke interferometer analysis of microstructures.

[0013] Dynamic parameter measurement: Laser interferometers can measure the angle of motion of the axis of motion, vibration frequency, etc., and analyze the laser linewidth by combining acousto-optic modulation technology.

[0014] With their nanometer-level precision and wide applicability, interferometers have become a core tool in scientific research and industrial inspection. From fundamental physics experiments to space observation, and then to microelectronics manufacturing and biomedical engineering, their technology continues to drive innovation in the field of precision measurement.

[0015] The distances between the optical components of an interferometer are typically adjusted and fixed manually. This includes the positions of reflectors, semi-transparent mirrors, and lasers. The positional relationships of these optical components directly determine the equipment's detection performance and even the accuracy of the detection results.

[0016] Human adjustments, influenced by personal experience and other uncertainties, are prone to errors.

[0017] In addition, once the interferometer is properly adjusted, the positions of the optical components are fixed during a single measurement. Therefore, regardless of whether the imaging effect is clear or not, it is difficult to make any further manual interventions. Summary of the Invention

[0018] The purpose of this invention is to provide an interferometer based on light speed adjustment to solve the problems existing in the prior art.

[0019] The above-mentioned technical objective of the present invention is achieved through the following technical solution: An interferometer based on light speed adjustment includes an interferometer system, the interferometer system including a laser and optical devices irradiated by the laser light from the laser, characterized in that: Includes a light-speed travel difference fine-tuning system; The light speed travel difference fine adjustment system includes a glass tube, a transparent liquid container, and a bidirectional pump; The glass tube has a liquid supply port on its side wall, which is connected to one pump port of a bidirectional pump. The other pump port of the bidirectional pump is connected to a transparent liquid container, which contains a light-transmitting liquid. Inside the glass tube is a floating, transparent sheet with a density less than that of the transparent liquid. The sheet is used to eliminate unevenness on the surface of the transparent liquid. The glass tube has a flat and transparent structure at least in the middle of both ends; A vertical optical path exists between the laser and at least one of the optical devices, and the glass tube is vertically disposed in the vertical optical path; Both the upper side wall of the glass tube and the upper part of the transparent liquid container are provided with a vent, and the two vents are connected. The air pressure at the top of the glass tube is stabilized during liquid level changes by using two vents, thereby improving control accuracy.

[0020] The transparent liquid uses methyl silicone oil.

[0021] The light speed travel difference fine adjustment system using methyl silicone oil features colorless and transparent properties with good light transmittance, temperature resistance (-50℃~200℃), low volatility inside the equipment, stable chemical properties over a very long period of time, moderate liquid viscosity, and high adjustment sensitivity and precision.

[0022] The speed of light in air is generally taken as 3 × 10⁻⁶. 8 m / s.

[0023] The refractive index of methyl silicone oil at 25°C typically ranges from 1.390 to 1.410, with slight variations depending on viscosity and temperature. For example, low-viscosity silicone oil has a refractive index of 1.375, while medium-to-high viscosity silicone oil has a refractive index of 1.403. Taking a typical refractive index of 1.395 as an example, the speed of light is calculated to be 2.15 × 10⁻⁶. 8 m / s.

[0024] In this invention, the travel distance of light in a transparent liquid is adjusted by adjusting the liquid level in the glass tube, thereby achieving high-precision optical path (optical path difference) adjustment.

[0025] Taking methyl silicone oil as an example, the difference in the speed of light between the two is 0.85 × 10⁻⁶. 8 m / s, which is 28% of the speed of light in air. When the liquid level in the glass tube is adjusted to 1 mm, it is equivalent to adjusting the position of the optical device by only 0.28 mm.

[0026] It allows for adjustments to larger liquid levels, equivalent to adjusting the liquid level in a smaller glass tube. Therefore, the adjustment precision is greatly improved.

[0027] Transparent liquids can be made from pure water.

[0028] Pure water has a sufficiently high light velocity and good chemical stability, allowing for more precise adjustments.

[0029] Above the liquid level in the glass tube, inside the transparent liquid container, the remaining space outside the liquid is a negative pressure space. Negative pressure is a pressure state below one atmosphere, ensuring that the gas density is low enough.

[0030] This avoids nonlinear interference caused by changes in liquid level due to gas pressure, greatly improving adjustment accuracy.

[0031] Furthermore, the cross-sectional area of ​​the inner cavity of the glass tube is greater than 4 square centimeters.

[0032] By using a thicker glass tube, more liquid can be dispensed to change a smaller liquid level. This allows for the use of a less precise bidirectional pump, enabling accurate liquid level adjustment.

[0033] Furthermore, the bidirectional pump is a peristaltic pump, and the flexible tubing of the peristaltic pump is set in a negative pressure container.

[0034] Peristaltic pumps are characterized by their bidirectional operation and high delivery accuracy; however, traditional peristaltic pumps cannot be connected to negative pressure or negative pressure containers. This invention addresses this by placing the flexible tube of the peristaltic pump within a negative pressure container, achieving pressure balance with the liquid level above the glass tube and the transparent liquid container, thus avoiding the influence of external atmospheric pressure on the flexible tube. This makes the peristaltic pump usable and significantly improves the overall accuracy of the equipment.

[0035] In use, first perform a coarse adjustment manually to fix the approximate position of the optical components. Then perform a fine adjustment using the light speed travel difference fine adjustment system to achieve a high precision that is far greater than that obtained manually.

[0036] The glass tube has graduated markings on its wall to indicate the liquid level.

[0037] The edges of the transparent sheet are equipped with reflective strips to enable alignment with the scale markings for easy reading.

[0038] It also includes a microprocessor system and a camera system for reading interferometric images; The microprocessor system controls the bidirectional pump and reads the interference images via a camera system; The microprocessor system controls the bidirectional pump to adjust the liquid level in the glass tube until the interference image is close enough to the preset image, at which point the bidirectional pump stops.

[0039] This is considered a single (optical path difference) adjustment. This self-feedback automatic adjustment, achieved through interference image recognition, has a precision far exceeding that of traditional manual or electric displacement adjustments.

[0040] For applications such as high-precision length and displacement measurement; optical component inspection; astronomical observation; refractive index and medium analysis; quantum physics and microscopic research; and dynamic parameter measurement, improving accuracy is of significant physical, industrial, and market importance. Attached Figure Description

[0041] Figure 1 This is a partial optical path diagram of the present invention. Detailed Implementation

[0042] The present invention will be further described in detail below with reference to the accompanying drawings.

[0043] An interferometer based on light speed adjustment includes an interferometer system 4, wherein the interferometer system 4 includes a laser 3 and an optical device 1 irradiated by the laser light from the laser 3, characterized in that: Includes a light-speed travel difference fine-tuning system; The light speed travel difference fine adjustment system includes a glass tube 2, a transparent liquid container, and a bidirectional pump; The glass tube 2 has a liquid supply port on its side wall, which is connected to one pump port of a bidirectional pump. The other pump port of the bidirectional pump is connected to a transparent liquid container, which contains a light-transmitting liquid. Inside the glass tube 2, there is a floating transparent sheet with a density less than that of the transparent liquid. The sheet is used to eliminate the unevenness of the liquid surface. The glass tube 2 has a flat and transparent structure at least in the middle of both ends; There is a vertical optical path between the laser 3 and at least one of the optical devices 1, and the glass tube 2 is vertically arranged in the vertical optical path; Both the upper side wall of the glass tube 2 and the upper part of the transparent liquid container are provided with a vent, and the two vents are connected. The air pressure at the top of the glass tube is stabilized during liquid level changes by using two vents, thereby improving control accuracy.

[0044] The transparent liquid uses methyl silicone oil.

[0045] The light speed travel difference fine adjustment system using methyl silicone oil features colorless and transparent properties with good light transmittance, temperature resistance (-50℃~200℃), low volatility inside the equipment, stable chemical properties over a very long period of time, moderate liquid viscosity, and high adjustment sensitivity and precision.

[0046] The speed of light in air is generally taken as 3 × 10⁻⁶. 8 m / s.

[0047] The refractive index of methyl silicone oil at 25°C typically ranges from 1.390 to 1.410, with slight variations depending on viscosity and temperature. For example, low-viscosity silicone oil has a refractive index of 1.375, while medium-to-high viscosity silicone oil has a refractive index of 1.403. Taking a typical refractive index of 1.395 as an example, the speed of light is calculated to be 2.15 × 10⁻⁶. 8 m / s.

[0048] In this invention, the travel distance of light in the transparent liquid is adjusted by adjusting the liquid level in the glass tube 2, thereby achieving high-precision optical path (optical path difference) adjustment.

[0049] Taking methyl silicone oil as an example, the difference in the speed of light between the two is 0.85 × 10⁻⁶. 8m / s, accounting for 28% of the speed of light in air. When the liquid level in glass tube 2 is adjusted to 1mm, it is equivalent to adjusting the position of optical device 1 by only 0.28mm.

[0050] This allows for adjustments to a larger liquid level, equivalent to adjusting the liquid level in a smaller glass tube 2. Therefore, the adjustment accuracy is greatly improved.

[0051] Transparent liquids can be made from pure water.

[0052] Pure water has a sufficiently high light velocity and good chemical stability, allowing for more precise adjustments.

[0053] Above the liquid level in glass tube 2, within the transparent liquid container, the remaining space outside the liquid is a negative pressure space. Negative pressure is a pressure state below one atmosphere, ensuring a sufficiently low gas density.

[0054] This avoids nonlinear interference caused by changes in liquid level due to gas pressure, greatly improving adjustment accuracy.

[0055] Furthermore, the cross-sectional area of ​​the inner cavity of the glass tube 2 is greater than 4 square centimeters.

[0056] By using a thicker glass tube 2, more liquid can be dispensed to change a smaller liquid level. This allows for the use of a less precise bidirectional pump, enabling accurate liquid level adjustment.

[0057] Furthermore, the bidirectional pump is a peristaltic pump, and the flexible tubing of the peristaltic pump is set in a negative pressure container.

[0058] Peristaltic pumps are characterized by their bidirectional operation and high delivery accuracy; however, traditional peristaltic pumps cannot be connected to negative pressure or negative pressure containers. This invention addresses this by placing the flexible tube of the peristaltic pump within a negative pressure container, achieving pressure balance with the liquid level above the glass tube 2 and the transparent liquid container, thus avoiding the influence of external atmospheric pressure on the flexible tube. This makes the peristaltic pump usable and significantly improves the overall accuracy of the equipment.

[0059] In use, first perform a rough manual adjustment to fix the approximate position of optical component 1. Then perform a fine adjustment, using the light speed travel difference fine adjustment system to achieve a high precision effect that is far greater than the precision of manual adjustment.

[0060] The glass tube 2 has graduated markings on its wall to indicate the liquid level.

[0061] The edges of the transparent sheet are equipped with reflective strips to enable alignment with the scale markings for easy reading.

[0062] It also includes a microprocessor system and a camera system for reading interferometric images; The microprocessor system controls the bidirectional pump and reads the interference images via a camera system; The microprocessor system controls the bidirectional pump to adjust the liquid level in glass tube 2 until the interference image is close enough to the preset image, at which point the bidirectional pump stops.

[0063] This is considered a single (optical path difference) adjustment. This self-feedback automatic adjustment, achieved through interference image recognition, has a precision far exceeding that of traditional manual or electric displacement adjustments.

[0064] For applications such as high-precision length and displacement measurement; optical component inspection; astronomical observation; refractive index and medium analysis; quantum physics and microscopic research; and dynamic parameter measurement, improving accuracy is of significant physical, industrial, and market importance.

[0065] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. An interferometer based on light speed adjustment, comprising an interferometer system 4, the interferometer system 4 including a laser 3 and an optical device 1 irradiated by the laser light from the laser 3, characterized in that: Includes a light-speed travel difference fine-tuning system; The light speed travel difference fine adjustment system includes a glass tube 2, a transparent liquid container, and a bidirectional pump; The glass tube 2 has a liquid supply port on its side wall, which is connected to one pump port of a bidirectional pump. The other pump port of the bidirectional pump is connected to a transparent liquid container, which contains a light-transmitting liquid. Inside the glass tube 2, there is a floating transparent sheet with a density less than that of the transparent liquid. The sheet is used to eliminate the unevenness of the liquid surface. The glass tube 2 has a flat and transparent structure at least in the middle of both ends; There is a vertical optical path between the laser 3 and at least one of the optical devices 1, and the glass tube 2 is vertically arranged in the vertical optical path; Both the upper side wall of the glass tube 2 and the upper part of the transparent liquid container are provided with a vent, and the two vents are connected. The air pressure at the top of the glass tube is stabilized during liquid level changes by using two vents, thereby improving control accuracy.

2. The interferometer based on light speed adjustment according to claim 1, characterized in that, The transparent liquid uses methyl silicone oil.

3. The interferometer based on light speed adjustment according to claim 1, characterized in that, The transparent liquid is made from pure water.

4. The interferometer based on light speed adjustment according to claim 1, characterized in that, Above the liquid level in glass tube 2, inside the transparent liquid container, the remaining space outside the liquid is a negative pressure space.

5. The interferometer based on light speed adjustment according to claim 1, characterized in that, The cross-sectional area of ​​the inner cavity of the glass tube 2 is greater than 4 square centimeters.

6. The interferometer based on light speed adjustment according to claim 1, characterized in that, The bidirectional pump uses a peristaltic pump, and the flexible tubing of the peristaltic pump is set in a negative pressure container.

7. The interferometer based on light speed adjustment according to claim 1, characterized in that, The glass tube 2 has graduation markings on its wall; The transparent sheet has reflective strips along its edges to allow for alignment with the scale markings for easy reading.

8. The interferometer based on light speed adjustment according to any one of claims 1 to 7, characterized in that, It also includes a microprocessor system and a camera system for reading interferometric images; The microprocessor system controls the bidirectional pump and reads the interference images via a camera system; The microprocessor system controls the bidirectional pump to adjust the liquid level in glass tube 2 until the interference image is close enough to the preset image, at which point the bidirectional pump stops.

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