The screen on the opposite wall has some straight parallel stripes. There are some reflecting mirrors and vertical slit boards in the middle.
Maybe turn the mirror so that the light source shines on it. Light is reflected in another direction. Find another mirror, catch this beam of light, and reflect it again. If the light shines on the wall, there will only be a spot on the wall. After several reflections from the mirror, it is transmitted to the opposite direction. Finally, the guide light shines on the screen, allowing the exit door to open before entering.
There are 10 different light sources. 500
m-700
m.
There are 10 different slit widths.
0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, .1mm, 1.2mm, 1.3mm, 1.4mm.
The slit can be set at different distances from the screen.
Looking behind, there is also a screen on the upper back wall with parallel straight stripes.
Put a light source, the light source emits light, passes through the slit, and forms stripes on the screen, but they are inconsistent with the stripes on the wall.
He Xin said: "How can I open this?"
Instantaneous said: "No receiver? Just a screen."
Xiang Yu said: "This screen is the receiver."
He Xin said: "What signal should we receive?"
Xiang Yu said: "What color is the light?"
Instantaneous said: "But there are many stripes."
He Xing said: "Is that using a scattering prism?"
Xiang Yu said: "Then the stripes don't look very similar."
Instantaneous said: "This fringe looks like an interference fringe."
Light waves obey the principle of superposition of waves. In the area where two light waves are superimposed, the vibration of some points is always strengthened and the vibration of other points is always weakened. The phenomenon of forming a stable light intensity distribution in this area during the observation time is called light interference phenomenon.
Not any superposition of two light waves can cause interference. The coherence conditions of light waves are: (1) The frequencies of two light waves with the same frequency should be the same. Otherwise, the phase difference changes with rapid changes in time caused by the frequency difference between the two light waves. (2) The vibration directions are the same. (3) The phase difference is constant.
The necessary conditions for interference to occur are that the light waves have the same frequency, the same vibration direction, and a constant phase difference. Light waves that meet the interference conditions are called coherent light waves, and the corresponding light sources are called coherent light sources.
Duan Zhu said: "Is it okay to use two identical light sources? This way we can find two identical light sources."
Xiang Yu said: "No. The light waves generated by two ordinary independent light sources cannot interfere."
Even the light waves radiated from different parts of the same light source cannot meet the conditions of interference. Because the light waves emitted by the actual light source are wave trains, the vibration direction and phase of the wave trains emitted by the atoms at this moment and the wave train emitted at the next moment are random. The phases of the wave trains emitted at different moments meet when they meet. There is no fixed relationship. Only the same wave train emitted by the same atom can be coherent when it meets. To obtain two coherent light waves, the light waves emitted from the same light-emitting point must be used to obtain two related light waves through specific interference devices. When they meet, the frequency, vibration direction and initial phase of the two waves will follow the original light wave. Synchronously changing, there may still be a constant phase difference between each column of light waves, which can cause interference. When they meet, they must also meet the condition that the optical path difference of the two superimposed light waves does not exceed the wave train length of the light waves. The wave train lengths of light waves emitted by various light sources are not the same.
The interference conditions of light waves are: same vibration direction, same frequency, constant phase difference, and the optical path difference of the two light beams must be less than the wave train length of the light wave. The interference pattern on the screen consists of a series of parallel and equidistant light and dark straight stripes, and the distribution of the stripes follows a cosine square variation pattern. The distance between two adjacent bright or dark stripes is called the stripe spacing.
Shunpin said: "There are three robots here, and they are also replacing the light source, slits, and reflectors. They need to illuminate the opposite striped screen before they are assembled."
He Xin said: "I will replace the light source, Xiangyu will replace the slit, and Instant Frequency will replace the reflector."
After He Xin changed the light source, the opposite robot A1 also changed the light source. After Xiang Yu changed the slit, the opposite robot A2 also changed the slit. After replacing the reflector instantly, the opposite robot A3 also replaced the reflector.
The segment resides at the moving slit distance. The opposite slit holder is in automatic movement distance.
The light source here passes through the slits to the reflector, is reflected back, passes through other slits, and reaches the screen behind. The light source on the opposite side passes through the slits to the reflector, is reflected back, passes through other slits, and reaches the screen in front.
Even without robot interference, there are nearly 1,000 combinations of light sources, slits, and distances. I don’t know how to combine them to make the light exactly consistent with the stripes.
This is equivalent to a three-digit combination lock. This means trying out 1,000 combinations.
Shunfeng said: "No, we don't need to try it 1,000 times. If we see that the stripes are inappropriate, we can know how to adjust the stripes."
Based on the wavelength, distance, and gap width, the width of the stripe can be obtained. But the stripe width is too large or too small. I don't know which parameter to adjust.
"But the parameters adjusted by the robot on the other side may prevent us from adjusting in the right direction." Shunfen said, "In other words, if the robot on the other side adjusts the wavelength smaller, we should increase the wavelength."
He Xin said: "Is this the rule? We will gradually adjust the three parameters contrary to the adjustment of the opposite robot."
When it is close to the appropriate value, the wavelength is too large, so turn it down another gear.
During the adjustment process, the robot's light source also shines and is aimed at the wall above the back. If the stripes match properly, Party A loses.
Several people from Party A also have to use baffles and reflectors to block the light from the robot's light source or reflect it in other directions.
Instantaneous said: "Wait a minute, you see, the spacing between the stripes above us and on the opposite side are the same."
Xiang Yu said: "Then the parameters used by the opposite robot are standard values."
Hexin said: "Use this value to configure the combination of light source, slit, and distance."
Finally, the wavelength of 589 nanometers was selected, the slit spacing was 0.9 mm, and the distance was 1.1 meters. The appropriate stripe width was obtained and the photoelectric switch was triggered. The door opened.
