Thin convex lens focal length measuring device and method based on electro-optical modulation

Abstract

The invention belongs to the technical field of optical lens focal length measurement, and particularly relates to a thin convex lens focal length measurement device and method based on electro-optical modulation. An electric signal is used for modulating a light source to enable the light source to emit light with a modulation signal, and after the light passes through a to-be-measured lens, a photoelectric conversion module converts the received light signal into an electric signal, the signal is demodulated into an original electric signal through a demodulation module, and the original electric signal is displayed on an oscilloscope; the distance between the to-be-measured lens and the light source is adjusted, the change of the amplitude of the electric signal is observedby using an oscilloscope, and when the maximum amplitude of the electric signal is observed, the distance between the to-be-measured lens and the light source is the focal length of the to-be-measured lens; knowledge points of optics, electricity, communication and the like are integrated, and the focal length of the optical lens is measured by adopting an electricity method; and the method has the advantages of scientific principle, simple experiment adjustment, convenient data observation, high stability and high measurement precision.

Description

Technical field: [0001] The invention belongs to the technical field of optical lens focal length measurement, and in particular relates to a thin convex lens focal length measurement device and method based on electro-optic modulation. The measurement of the focal length of an optical device is realized by an electrical method, and the measurement accuracy is high and the operation is simple and convenient. Background technique: [0002] Measuring the focal length of a thin convex lens is a basic experiment in university physics experiments. At present, the commonly used measurement methods include the self-collimation method and the conjugate method. For example, Chinese patent CN201720118329.7 discloses an experimental device for measuring the focal length of a thin convex lens. Screen, laser calibration device, using the laser calibration device to complete the adjustment of the coaxial contour of the optical system; adjust the height of the bracket so that the laser emi...

AI Technical Summary

Problems solved by technology

For example, Chinese patent CN201720118329.7 discloses an experimental device for measuring the focal length of a thin convex lens. Screen, laser calibration device, using the laser calibration device to complete the adjustment of the coaxial contour of the optical system; adjust the height of the bracket so that the laser emitted by the laser transmitter can pass through the center of the calibrator; by observing the pointer at the bottom of the bracket and the Read the coordinates of the point light source, the standard thin convex lens, the thin convex lens to be measured, and the light intensity detection probe at the coincident position of the scale on the optical bench; move the position of the light intensity detection probe and observe the light intensity reading changes on the display screen , study the distribution of light intensity in the image space of the thin convex lens to be tested, find the position of the maximum light intensity, thereby find the focal position of the thin convex lens to be tested, and finally achieve the purpose of measuring the focal length of the thin convex lens to be tested; this method relies on the light intensity reading Find the position of the lens to be tested corresponding to the maximum light intensity. The selection of the light source, object screen and image screen will also have a certain impact on the light intensity readings, and the measurement results may have large errors.

Chinese patent CN201720219441.X discloses an experimental instrument for measuring the focal length of a thin convex lens. It uses a CCD camera to capture the imaging spot, and accurately judges the size and intensity of the imaging spot in terms of value and image. It can be quickly and accurately measured and displayed clearly and intuitively. It is an experimental instrument for measuring the focal length of a thin convex lens in two modes, automatic and manual, to help students deepen their understanding of the imaging law of thin lenses, including: point light sources, adjustable diaphragms, thin convex lens components, image screens, and shading tubes , casing, movable track, adjusting gear lever, transmission device, infrared distance measuring device, display screen, CPU controller; this method is based on the conjugate principle, the judgment of imaging depends on the imaging quality of the camera, and the measurement method depends on CPU control, It is relatively complicated and not suitable as a teaching content for college physics experiments

Images