SU1541660A1 - Method of demonstration of optical interference and light diffraction - Google Patents

Abstract

The invention relates to teaching aids, in particular to educational devices in physics, and can be used in a series of physics courses. The purpose of the invention is to expand the demonstration capabilities, taking into account the degree of coherence of the light source. This goal is achieved by setting the interval and direction for reading information from a visible image, then converting the read information into an additionally created visible color image, calculating the interference color image, and comparing the effect of the degree of coherence as a result of the additional visible image light source. 2 Il.

Description

The invention relates to teaching aids, in particular to educational devices in physics, and can be widely used in a number of physics courses, such as, for example, optics, spectroscopy, computer technology, etc.

The purpose of the invention is to expand the demonstration capabilities, taking into account the degree of coherence of the light source.

FIG. 1 is a graphical diagram of the device; in fig. 2 is a block diagram of a computing device.

A device for demonstrating optical interference and diffraction, taking into account the degree of coherence of a light source, comprises a light source 1, for example, a mercury incandescent lamp,

a capacitor 2 for forming a uniform illumination, a movable 1 aim 3 serving to obtain a better visible image, a transforming optical element k - interchangeable with a Fresnel biprism or a slit, which makes it possible to obtain an interference or diffraction pattern, a screen 5 for visual observation of a physical appearance, information retrieval unit 6 designed to pick up the intensity signals from the screen by the photosensor and move it around the screen, the signal processing and control unit 7 designed to receive and send tempered the television color signal from the observed physical phenomenon, the television color projection device 8 forming

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color video image, projection screen 9, displaying information arriving at it graphically, demonstrating phenomenon 10 and the same calculated in advance similar 11, shown on screen 9.

In addition, the device (Fig. 2) contains a photosensor 12 for receiving information from the screen 5 of the demonstrated phenomenon 10, an amplifier 13 of the analog signal amplifying the signal from the photosensor 12 to a predetermined voltage level, for example

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interfering with waves, this circumstance results in a small interference field, which makes it difficult to visualize it on the screen. Then, including information retrieval unit 6, with the help of motors 17 and 18 (Fig. Photo sensor 12 is set to the lowest left position of the screen 5 in the zone of the interference pattern 10, the position of which is set by conversion unit 16, for example D / A converter, thereby assigning the channel counter value (fig, 3), denoting at

from 0 to 7 V, the conversion module Ik this, that the installation of the DAC-10 is initial

analog signal to digital and vice versa, for example, the type of CREIT CAMAC,

two-way communication

with niniavm and in turn containing

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digital in, for example, the cove zero position is complete. Then, setting the time interval for moving the photosensors 12 from point to point equal, for example, 1 s, along the horizontal axis, the photosensor 12 directly removes the intensity level of the pattern 10 by points, the number of which is set by the DAC-Yu, and is equal to 2-102 points . The signals from the photo sensor 12 are amplified by the amplifier 13 to the voltage level of the response of the analog-to-digital conversion unit 15, for example, ADC-1, where the analog signals are converted to

These are received from the photodiode 12, the digital-to-analogue digital conversion unit 16, for example, DAC-10, which controls the movement of photosensors 25 kz 12 using the motor 17 along and the motor 18 across the screen b, and the controller 19, for example K-16, The employee for organizing two-way communications to the zero position is complete. Then, setting the time interval for moving the photosensors 12 from point to point equal, for example, 1 s, along the horizontal axis, the photosensor 12 directly removes the intensity level of the pattern 10 by points, the number of which is set by the DAC-Yu, and is equal to 2-102 points . The signals from the photo sensor 12 are amplified by the amplifier 13 to the voltage level of the response of the analog-to-digital conversion unit 15, for example, ADC-1, where the analog signals are converted to

g miniature computer and k-transformation module, -Q digital values and through the controller

bi-directional bus 20 connected to the Q-BUS 5 bus 21, mini-computer 22 allowing to control, read and process the incoming information, unidirectional bus 23 for the subsequent transfer of information to the screen, color interface 2k, which forms the TV clock pulses and R, G, B-color signals, block 25 of conjugation of television sync pulses and K, C3B signals from interface 2k, block 26 of conjugation of television device 8, with the help of which a visible color image is generated

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19 and the bidirectional information bus 20 is fed to a common Q-BUS 21 mini-computer 22, for example, Electronics-60, in which peripheral devices communicate with the central processor and RAM through an internal trunk bus system, where the trunk has lines for alternate transmission over him addresses and data. In the mini-computer, the signals of the measured intensities I (K) are brought into the array I (K) and output to the tper screen of the projection screen 9 via the 2k interface, which forms a color R,

interfering with waves, this circumstance leads to a small interference field, which makes it difficult to visualize it on the screen. Then, including the information acquisition unit 6, with the help of the motors 17 and 18 (Fig. 2), the photosensor 12 is set to the lowest left position of the screen 5 in the zone of the interference pattern 10, the position of which is set by the conversion unit 16, for example, D / A converter, thereby Channels assigns a value (FIG. 3), denoting at

This, that the installation of the DAC-10

to zero position finished. Then, setting the time interval for moving the photosensors 12 from point to point equal, for example, 1 s, along the horizontal axis, the photosensor 12 directly removes the intensity level of the pattern 10 by points, the number of which is set by the DAC-Yu, and is equal to 2-102 points. The signals from the photo sensor 12 are amplified by the amplifier 13 to the voltage level of the response of the analog-to-digital conversion unit 15, for example, ADC-1, where the analog signals are converted to

digital values and through the controller

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19 and the bidirectional information bus 20 is fed to a common Q-BUS 21 mini-computer 22, for example, Electronics-60, in which peripheral devices communicate with the central processor and RAM through an internal trunk bus system, where the trunk has lines for alternate transmission over him addresses and data. In the mini-computer, the signals of the measured intensities I (K) are brought into the array I (K) and output to the tper screen of the projection screen 9 via the 2k interface, which forms a color R,

on a color television project C, In the image, block 25,

screen 9.

The operation of the device on the example of interference when using Fresnel biprism.

The light from the source 1 of the scythe is formed by the condenser 2 and illuminates a uniformly moving slit 3. The transmitted light that passes through the slit 3 hits the Fresnel k biprism with which the interference pattern 10 on the screen 5 is formed. Since the refracting angles of the bi-prism are very small for to ensure a small distance between

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matching the output clock pulses and H, C, B signals of the interface 2k with the input signals of the complete television device 8 through the block 26 of its interface. When issuing the next intensity signal, the screen of the photo sensor is moved by the DAC to a new position, and after a time interval of 1 second, the new intensity level I (K) is read, which is displayed on the screen until the entire screen is passed.

Know the wavelength, the distance from the Fresnel biprism to the screen, the aperture,

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matching the output clock pulses and H, C, B signals of the interface 2k with the input signals of the complete television device 8 through the block 26 of its interface. When issuing the next intensity signal, the screen of the photo sensor is moved by the DAC to a new position, and after a time interval of 1 second, the new intensity level I (K) is read, which is displayed on the screen until the entire screen is passed.

Know the wavelength, the distance from the Fresnel biprism to the screen, the aperture,

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On the projection screen, a pre-calculated interference pattern is constructed using the formula for the dependence of intensity on the order of interference. As a result, a pre-calculated pattern 11 is formed on the projection screen and is directly removed from the displayed event 10, where they are displayed on it in different colors.

Since the visibility of the interference pattern is directly equal to the fraction of the coherence of the light present in the interfering light beams, therefore changing the visibility of the pattern on the screen allows us to determine the intensity fraction of the coherent components of these light beams and thereby actually reflect this on the projection screen.

Similarly, the device also works when replacing a Fresnel biprism with a slit, with the only difference that a diffraction pattern is built in advance on a color television screen according to predefined 25 initial conditions based on known dependencies.

Changing the light source and the transition to a coherent one, demonstrate a clear picture of the resulting phenomenon. By changing the different conditional parameters of the initial conditions, this device clearly tracks any change in their visual representation,

The proposed device allows

whose fuser is attached a photo sensor, whose surface serves as a screen when it is installed vertically, the module 14 for converting signals of the KREIT-KAMAK type with standard blocks ADC-14, DAC-10, K-16, mini-Electronics Electronics-60, or DVK-2 (3, 4) color interface CDR-1, projection

color MI

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TV 01 HRC, as well as mates, matching levels of input and output signals Demonstration and didactic perception are increased due to the fact that this device compares real physical phenomenon with its theoretical representation in real time with the possibility of changing physical quantities such as wavelength, slot size, screen distance, laser cavity length, etc. with simultaneous observation of these changes on the screens in the above representations. V

The demonstration possibilities are extended due to the fact that the proposed method allows observing and de- ming to observe any optical phenomena with the possibility of high resolution. i

Claims (1)

Invention Formula A method of demonstrating optical interference and diffraction of light, to expand the possibility of demonstrations that transform light energy to optics, as it provides a visible image, which is a monster of low-resolution and poorly-illuminated optical phenomena, as well as the possibility of their comparison with a pre-calculated phenomenon according to a known law, such as diffraction by a filament, diffraction at the edge of the screen, gas laser mode, the correlation radius of the light source coherence, and so on. d., and thus give a correct idea of this phenomenon, To demonstrate a number of optical phenomena, standard devices are used: PDS-021 two-coordinate recorder, on horizontal 40 In order to expand the demonstration capabilities, taking into account the degree of coherence of the light source, the interval and direction of reading information from the visible image are further specified, followed by conversion of the read information into the additionally created visible color image, and the resulting color image is calculated comparing it with the additionally created visible image determines the degree of coherence of the light source. 45 M6606 whose fuser is attached a photo sensor, whose surface serves as a screen when it is installed vertically, the module 14 for converting signals of the KREIT-KAMAK type with standard blocks ADC-14, DAC-10, K-16, mini-Electronics Electronics-60, or DVK-2 (3, 4) color interface CDR-1, projection 0 five 0 five ny color MI tv electronics 0 TV 01 PCs, as well as mates, matching levels of input and output signals Demonstration consistency and didactic perception are increased due to the fact that in this device the real physical phenomenon is compared with its theoretical representation in real time with the ability to change a number of physical quantities such as wavelength, slot size, screen spacing, laser cavity length, etc. with simultaneous observation of these changes on the screens in the above representations. V The demonstration possibilities are extended due to the fact that the proposed method allows observing and de- ming to observe any optical phenomena with the possibility of high resolution. i Invention Formula The method of demonstration of optical interference and diffraction of light, including and with In order to expand the demonstration capabilities, taking into account the degree of coherence of the light source, the interval and direction of reading information from the visible image are further specified, followed by conversion of the read information into the additionally created visible color image, and the resulting color image is calculated comparing it with the additionally generated visible image determines the degree of coherence of the light source. l з I