Shulou(Shulou.com)11/24 Report--

Is the colored light colorful?

Is the gray light a gray light?

No, neither.

Color light and gray light are commonly used optical signals in the field of optical communication, which are invisible to the naked eye.

What kind of light is invisible to the naked eye? As shown in the figure below, the light in the 380nm~780nm wavelength range is visible light, which is visible to the naked eye, such as rainbows, while other wavelengths are invisible light, which is invisible to the naked eye, such as X-rays, ultraviolet rays, infrared rays, microwaves and so on.

Optical communication refers to optical fiber communication, in which optical signals can be transmitted in optical fiber. Optical communication is widely used in OTN, SDH, IP and other networks.

The wavelength range of optical communication is 850nm~1650nm, which is located in the near infrared region. The light in this wavelength range belongs to invisible light.

Color light and gray light are used for optical communication, so they are also invisible light.

Which position is the color light or the gray light? According to the regulations of ITU-T, the wavelength of optical communication is divided into 850band, O band, E band, S band, C band, L band and U band. For a detailed introduction of the optical band, you can refer to the three band rookies of optical communication, don't you know? ".

The 850th band is window 1 (850nm window).

The O-band is window 2 (1310nm window).

C-band is window 3 (1550nm window).

The L-band is the fourth window.

The E-band is the fifth window.

The S and U bands are not defined.

At present, 850band (850nm window), O band (1310nm window), C band (1550nm window) and L band light are widely used in optical communication.

The color light is located in the C band (1550nm window), and the gray light is located in the 850th band (850nm window) and O band (1310nm window).

What is color light and gray light? Color light: light located in the 1550nm window, the light signal has a standard wavelength. It is usually used in OTN networks and is suitable for long-distance transmission scenarios.

Gray light: light located in 850nm and 1310nm windows, the light signal does not have a standard wavelength. It is usually used in SDH, IP and other networks, and is suitable for short-distance transmission scenarios.

Simply understand, color light and gray light are not an optical signal, but many optical signals within a certain wavelength range, some optical signals have standard wavelengths, some optical signals do not have standard wavelengths.

Next, let's first introduce what is a standard wavelength optical signal and an optical signal without a standard wavelength.

Standard wavelength means that the optical signal fluctuates in a very small range near a certain central wavelength, which is a single wavelength of light.

No standard wavelength means that the optical signal fluctuates in a certain range, which is a wide range and has no central wavelength.

For example, to help people understand color light and gray light.

Color light is like a sniper rifle, firing a long distance, firing only one bullet at a time, causing a bullet hole to hit the bull's-eye, then the bullet is a light signal with a standard wavelength.

Grey light is like a shotgun, the firing distance is short, and many bullets are fired at the same time, causing multiple bullet holes to hit the bull's-eye, so these bullets do not have a standard wavelength light signal.

Who will provide color light and gray light? Light module to provide color light and gray light.

Color light module: send and receive color light signals with standard central wavelength.

Gray module: send and receive gray light signal without central wavelength.

Combined with the actual network equipment, we look at the application and deployment of color light and gray light in the network.

The SDH / IP equipment on the client side emits gray light through the gray light module to enter the OTN network, and the OTN device completes the conversion from gray light to color light, which is transmitted in the OTN network through the color light module of the OTN equipment.

Summary: nowadays, color light and gray light are widely used in optical communication, which realizes the efficient carrying and transmission of light in optical fiber, satisfies the short-distance and long-distance transmission scenarios of various networks, and promotes the rapid development of optical communication network.

This article comes from the official account of Wechat: ZTE documents (ID:ztedoc)

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