The principle of anti reflection coating, what is the principle of anti reflection coating

Light has wave-particle duality, i.e., it can be understood as both a wave and a beam of particles moving at high speed at the microscopic level (note, don't think of it as a simple wave and a simple particle here). They are all microscopic, and Einstein named them photons through his research. The wavelength of the red light wave = microns The wavelength of violet light = microns.

Whereas the mass of a photon is kilograms. So they are far from the macroscopic waves and particles we think. The principle of anti-reflection coating is to consider light as a kind of wave, because light waves have the same interfering properties as mechanical waves.

Apply a layer of anti-reflection coating to the front of the lens (generally"Calcium fluoride", slightly soluble in water), if the thickness of the film is equal to a quarter of the wavelength of the red light (note: red light is spoken of here) in the anti-reflection coating, then the red light reflected back on both sides of this film will interfere and cancel each other out, and you will not see a little reflection in front of the lens, because this red light has already passed through the lens. Why do we never see lenses without reflections?

The reason is very simple, because visible light has seven colors: "red, orange, yellow, green, blue, indigo, and violet", and the thickness of the film is unique, so it can only take care of one color of light to let it fully enter the lens, and under normal circumstances, all the green light is entered, in this case, the color of the lens reflection you see in the visible light is blue-violet, because there is no green light in the reflected light. The thickness of the film can also be determined based on the color characteristics of the lens. The function of the visible anti-reflection coating is to reduce the intensity of the reflected light, thereby increasing the intensity of the transmitted light, so that the optical system can be imaged more clearly.

Apply a layer of anti-reflection coating to the front of the lens (generally"Calcium fluoride", slightly soluble in water), if the thickness of the film is equal to a quarter of the wavelength of the red light (note: red light is spoken of here) in the anti-reflection coating, then the red light reflected back on both sides of this film will interfere and cancel each other out, and you will not see a little reflection in front of the lens, because this red light has already passed through the lens.

Why have I never seen a lens without reflections? The reason is very simple, because visible light has seven colors: "red, orange, yellow, green, blue, indigo, and violet", and the thickness of the film is unique, so it can only take care of one color of light to let it fully enter the lens, and under normal circumstances, all the green light is entered, in this case, the color of the lens reflection you see in the visible light is blue-violet, because there is no green light in the reflected light. The thickness of the film can also be determined based on the color characteristics of the lens.

The principle of anti-reflection coating is that the anti-reflection coating uses the interference of light.

Light has wave-particle duality, that is, it can be understood as a wave and a beam of high-speed moving particles from the microscopic level, with the property of interference. The anti-reflection coating is taken to enhance the reflective effect.

When the light hits the interface of two transparent media, if the light is emitted from the optically dense medium to the optophobic medium, the light may be fully reflected. When light is emitted from an optically phobic medium to a light-dense medium, the reflected light has a half-wave loss.

For the anti-reflection coating on the glass lens, the refractive index is between the refractive index of the glass and the air, when the light is sold from the air to the lens, the reflected light on both sides of the film is lost by half a wave, so that the thickness of the film only meets the optical path difference of the two reflected lights is half a wavelength.

The reflected light on the back surface of the film travels more distance than the reflected light on the front surface, i.e., the target is twice the thickness of the film. Therefore, the thickness of the film should be 1 4 of the wavelength of the light in the thin film medium, so that the two reflected lights cancel each other out.

Anti-reflection coating features

It can be seen that the thickness of the anti-reflection coating d 4n (where n is the refractive index of the film such as Li, which is the wavelength of light in the air in the posture) The principle of the anti-reflection coating is to consider light as a wave, because light waves have the same interference properties as mechanical waves.

Anti-reflection coating generally refers to anti-reflective coating. Anti-reflection coating, also known as anti-reflection coating, its main function is to reduce or eliminate the reflected light from optical surfaces such as lenses, prisms, and plane mirrors, thereby increasing the light transmission of these elements and reducing or eliminating stray light in the system.

The principle of <> anti-reflection coating is to consider light as a kind of wave, because light waves have the same interference properties as mechanical waves, when a layer of anti-reflection coating is applied in front of the lens, when the thickness of the film is equal to a quarter of the wavelength of red light, the red light reflected back on both sides of this film will interfere, thus canceling each other. Reflections will not be visible in front of the lens, as the red light has all passed through the lens. That is, the anti-reflection coating is used to reduce the reflected light on the surface of the element.

In optical instruments, the reflection on the surface of optical components not only affects the luminous energy of optical components, but also forms stray light in the instrument, affecting the imaging quality of optical instruments. In order to solve these problems, a single or multi-layer film of a certain thickness is usually coated on the surface of the optical component, in order to reduce the reflected light on the surface of the component.